## Tipping points/elements

There has been quite lot of discussion recently about climate tipping points, or tipping elements. It’s mostly motivated by a recent Nature comment suggesting that Climate tipping points [are] too risky to bet against. The suggestion is that some the tipping points (West Antarctic Ice Sheet, Greenland Ice Sheet) may triggered sooner than we have anticipated. Hence, we should take this seriously and that international climate action should reflect this. One particular issue would be if there were a cascade of tipping points that, when combined, lead to some new climate state.

However, there do seem to be some who don’t entirely accept this argument, and I can see why. A lot of what is suggested about tipping points is quite speculative; it’s very difficult to quantify the actual likelihood of them being triggered. Also some (like ice sheet retreat) might still be quite slow and may not even be truly irreversible. Hence, I understand why there is some reluctance to make this a major aspect of the narrative.

However, I am starting to think that there is a problem with how we typically discuss this topic; we tend to focus more on what we think will probably happen and not enough on what might happen. Even though what will probably happen could be pretty severe, the low-probability, high-impact outcomes carry the greatest risk. So, I do think we should be talking more about the potential worst-case scenarios, but I’m not entirely sure of how best to do so.

One problem is that the outcome is conditional on what we do in future, and there are a large number of uncertainties associated with that future – what do we do in terms of future emissions, how will our emissions be taken up by the carbon sinks, how will the climate respond to the resulting atmospheric concentration, what will be the impact of this climate response, and how will we then respond to these impacts? In some sense, it’s a continually moving target.

If we fail to limit our emissions, then it becomes more likely that some of the more serious outcomes will materialise. If we start to limit our emissions, then they become less likely. If we have to consider what future pathway we might follow, what will probably happen if we follow that pathway, and also what could happen if we’re unlucky, it all gets rather convoluted. Also, if we do start to limit our emissions, do we stop talking about some of the worst case scenarios that would now be less likely than they had been before, or do we continue to highlight them in case we then start to take emission reductions less seriously?

Also, some of the tipping points/elements are so uncertain that we may have already almost triggered them, or it could still take a fairly substantial amount of additional warming. How should this influence our thinking? Clearly, if we want to avoid them we should aim to limit our emissions, but if we’re not really sure when they’d be triggered, how do we balance this with all the other factors that should influence how we go about reducing our emissions?

As you can probably tell, even though I think it is important to highlight some of the more extreme, worst-case outcomes, I’m still not sure how to do this in a way that accounts for all of the uncertainties, without it becoming so convoluted that it’s difficult to explain clearly. Similarly, how do you avoid simplifying it to the point where it is open to valid criticisms? Maybe other people have some ideas of how to do this. If so, I’d be interested to hear them.

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### 249 Responses to Tipping points/elements

1. morpheusonacid says:

How did you get a tipping point in thermodynamics? This concept is just part of the spreading of fear. Thermodynamics is driven by temperature differences which tend to an equilibrium. It is a stable process.

2. I have NEVER seen a so-called “tipping point” identified before it occurred. Nor do we have any understanding of what the leadup to a “tipping point” might look like.

In fact, we don’t even have a definition of a “tipping point” that reliably distinguishes it from say a “turning point” where for example things were getting warmer for a while but now they’re cooling down.

Not only that, we don’t even have an agreed-upon list of “climate tipping points” throughout history.

What we do have, however, is a wonderful term to scare people with—”If you do not cease your evil carbocrimes, you will surely bring on the dreaded climate tipping point, and boy will you be sorry!”

Come back when you’ve solved those problems and we can discuss the issues you’ve raised. Until then, you’re just engaging in what we used to call “hitchhiking to Chicago” complete with the obscene hand gestures …

Regards,

w.

3. morpheus,
In this case, it refers to something that either starts to change in a way that is essentially irreversible, or that flips the system into a new state. For example, the West Antarctic Ice Sheet could start a process of irreversible melting. It’s, of course, limited by how much ice it has, but once started it may be virtually impossible to stop. Similarly, there are tipping points associated with Greenland, the Amazon rainforest, tropical coral reefs. It doesn’t only refer to the global climate system.

4. Willis,
You’re sort of illustrating one of the issues; how does one discuss this important issue in a way that doesn’t end up being dismissed? Admittedly, you’re clearly not actually interested in taking this seriously, but it’s still important to think about how to avoid presenting things that are then easy targets for those who are looking for ways to undermine the need to take this issue seriously?

5. …and Then There’s Physics says:
November 30, 2019 at 10:04 pm

Willis,
You’re sort of illustrating one of the issues; how does one discuss this important issue in a way that doesn’t end up being dismissed? Admittedly, you’re clearly not actually interested in taking this seriously, but it’s still important to think about how to avoid presenting things that are then easy targets for those who are looking for ways to undermine the need to take this issue seriously?

Dear heavens, ATTP, miss the point much? My whole plea was for you to take this damn issue seriously by:

1) Defining just WTF you are talking about.

2) Identifying a number of observations that would let us distinguish a turning point from a tipping point.

3) Developing a list of what your criteria identify as climate tipping points through history.

Until you do that you’re just playing with your dick and pretending you’re doing science. But instead of actually taking it seriously, you’d rather try to bite my ankles with your ludicrous accusations about my supposed motives.

Take it seriously? Medice, cura te ipsum!

w.

6. Willis,
If you’d read the post, you might have noticed that I do think this is a tricky issue to discuss. I think that quantifying when tipping points, or turning points, might happen is not straightforward. However, as an example, if we lost the West Antarctic Ice Sheet, or Greenland, even if we did manage to limit emissions, then that would illustrate that we crossed some threshold where it was changing irreversibly. However, one of the reasons for highlighting this kind of outcome is to – ideally – avoid it actually happening. If we simply wanted to know how we could tell if it was happening, it would be pretty easy.

you’d rather try to bite my ankles with your ludicrous accusations about my supposed motives.

They may well be wrong, but they’re hardly ludicrous.

7. Thank you for framing this post in such a rational and reasonable manner. As to your question of when would we adjust the way we discuss the question tipping points, I would suggest that we would not change the manner of discussion until we are looking at several years that show that we have altered the trajectory of the Keeling Curve.

Thanks again,

Mike

8. ecoquant says:

Pertinent refs:

* E. Baldwin, “Choosing in the dark: Incomplete preferences, and climate policy“, February 2018.
* M. Weitzman, “On modeling and interpreting the economics of catastrophic climate change“, The Review of Economics and Statistics, February 2009. (The original of Weitzman’s Dismal Theorem.)
* M. Weitzman, “Fat-tailed uncertainty in the economics of catastrophic climate change“, Review of Environmental Economics and Policy, 5(2), Summer 2011, Pages 275-292.

Baldwin, in particular, offers a clever decision theory under incomplete information where actions are preferred if they optimize over all possible “tastes and beliefs”. Accordingly, an action is deemed good and recommended if, no matter what the tipping points we are approaching or not, outcomes and means appeal to everyone’s interest.

9. small,
Yes, I tend to agree that the key thing is to get emissions to start reducing. Then we can ague about how fast.

eco,
Thanks, I’ll have a look at those. I have read the latter one, I think.

10. ecoquant says:

@Willis,

There are many physical systems — and geophysical ones — which can, with nudges, transition into states which are irreversible, or at least reversible with great difficulty. Both the closing of the isthmus at Panama and the breaching of the Mediterranean Sea’s rift valley by the Atlantic Ocean were both such events, events which caused massive realignment of regional climates. One can also imagine the jökulhlaups produced similar effects.

The simplest physical example is a dike wall or sea wall which is fine-fine-fine, until it is breached, or, more pertinently, grounding line instability at some Antarctic glaciers.

11. …and Then There’s Physics says:
November 30, 2019 at 10:20 pm

Willis,
If you’d read the post, you might have noticed that I do think this is a tricky issue to discuss. I think that quantifying when tipping points, or turning points, might happen is not straightforward. However, as an example, if we lost the West Antarctic Ice Sheet, or Greenland, even if we did manage to limit emissions, then that would illustrate that we crossed some threshold where it was changing irreversibly. However, one of the reasons for highlighting this kind of outcome is to – ideally – avoid it actually happening. If we simply wanted to know how we could tell if it was happening, it would be pretty easy.

All of that handwaving is wonderful, but you haven’t even begun to address the issues I raised above, viz:

1) Defining just WTF you are talking about.

2) Identifying a number of observations that would let us distinguish a turning point from a tipping point.

3) Developing a list of what your criteria identify as climate tipping points through history.

Finally, referring to your false claim that I didn’t really want these issues to be taken seriously, an ugly lie for which you have absolutely no evidence, I’d said:

you’d rather try to bite my ankles with your ludicrous accusations about my supposed motives.

To which you replied:

They may well be wrong, but they’re hardly ludicrous.

ATTP, your vile accusations about my supposed motives are hilariously and completely wrong. More to the point, such ugly attempts at character assassination have no place in a scientific discussion. You are destroying your own reputation with your attempt to slime me. Do you think you can bring yourself to set your nastiness aside and stick to the science?

w.

12. Willis,
Calm down. You really don’t get to be a regular contributor to WUWT and then complain about character assassinations and suggest others stick to the science (well, you can, but expecting others to take you seriously would be naive). If you’re serious about sticking to the science, you really do have a lot to do before anyone is going to take you seriously.

13. Joshua says:

> However, I am starting to think that there is a problem with how we typically discuss this topic; we tend to focus more on what we think will probably happen and not enough on what might happen.

Not just this tooic imo. It’s a problem that affects the issue of climate change more generally. People have a hard time making policiss to address uncertainty. So instead of accepting the context of decision-making in the face of uncertainty, they either create a false certainty or whine about uncertainty such that they smf see past it (see Willis above).

14. ecoquant says:

@Joshua,

It’s not just “uncertainty”, which is a pretty nebulous thing to most people: It might be stochastic uncertainty, but it can also be weighting sources telling them things with lower confidence (perfectly legitimate in a Bayesian approach), or it can be a perceived cost of action given embrace of a particular picture of the world. For example, in another space hereabouts, I opined that the IPCC faulted by failing to introduce loss functions into their outcome distributions when they gauged outcomes of various phenomena. As I remarked, I can entirely understand why they chose to do this, because of the Garage Shed Problem and other things, and because they felt they’d then need to bring economists directly into the process, which could be unwieldy. But, as a consequence, the only path left to them was to try to be “objective”, another loaded and somewhat nebulous concept, and one easy to challenge.

So it’s not just uncertainty and its complexities, it’s also things like lags and tradeoffs. It is natural to think people are sufficiently familiar with these in these day-to-day to understand them, but using them, and packaging them into conceptual with the ability to reason with them with facility are two different things.

Frankly, dealing with climate policy concepts, as well as environmental policy and a whole plethora of policies from health risks to crime to education demands numeracy as a skill, let alone logic. And these aren’t as plentiful as they should be. One can quibble about why — modern media has a big role, I think — but their absence basically means the public are ill-suited to reasoning about and choosing these things.

It’s not their fault. But it not being their fault won’t protect them from the consequences of poor choices. That’s hard news. But we can try to persuade, rhetorically and economically.

15. ecoquant says:

@Joshua,

Ironically, I am just reading L. J. Savage’s 1951 paper on “The theory of statistical decision”, cited by Elizabeth Baldwin in the paper I linked above. Not too far into the paper Savage writes:

Traditionally, the central problem of statistics is to draw statistical inferences, that is, to make reasonably secure statements on the basis of incomplete information. This entails other problems, particularly that of designing experiments which permit the strongest inference for the expenditure involved. The new theory under discussion, however, centers about the problem of statistical action rather than inference, that is, deciding on a reasonable course of action on the basis of incomplete information. There is clearly an abundance of situations calling for statistical action.

Indeed.

So, I think, too, a great responsibility is education, both for more numerate approaches to things, and on climate and environment. Fortunately, on the former, trends are, I believe, on our side: For example, most modern businesses are run in an evidence-based way and this is how business schools teach their students management should be done. See, for instance, the great book,

B. S. Baumer, D. T. Kaplan, N. J. Horton, Modern Data Science with R, CRC Press, 2017

to see a great collection of the skills entailed.

16. ecoquant says:

(Sorry for the failure to close the emphasis.) [Mod: fixed]

17. [#ButModulz. -W]

18. Rob says:

Willis has a masters in obfuscation: “tipping” changes the balance such that it does not recover, but “turning” is recoverable.
On topic, perhaps look to Occam.
Most energy is absorbed in the oceans, and these will affect albedo (disappearing ice).
Atmospheric CO2 content is long-lived, so whatever is there presently will mostly still be there in another 100 years. Along with other GHGs this amplification of warming based on the differential (2019 – pre-industrial revolution) is set to continue unless geoengineering occurs.
In very simple terms the question no longer seems “are we there yet?”

19. ecoquant says:

@Willis Eschenbach,

And what about the rest of us, Mr Eschenbach? Why are you ignoring us? Could it be you don’t like our challenges because you have no response, eh?

20. ecoquant says:

@Willis Eschenbach,

Oh, thank you kind master of doubt, for paying attention.

Nope. Not models. Concepts. Grounding lines on Antarctic glaciers are not models. They exists. They have been verified experimentally, in the field, with undersea robots. Ice is buoyant. The grounding line crisis is very similar to the joküaups crisis, or the dike crisis. These are not hypotheticals.

So?

21. [No piling on, please. -W]

22. [Snip. -W]

Tipping points cannot be KNOWN as fact until they happen. The problem is we cannot allow them to occur! It would not be desirable!!!

Climate switch brought on by meteor did not do the dinosaurs any good. Milankovitch cycles (or something ) cause climate to switch between cold and warm. The breakout of “Lake Agassiz. As ice-dam configurations failed, a series of great floods were released from Lake Agassiz, resulting in massive pulses of freshwater added to the world’s oceans.” This caused is most likely the cause of the younger Dryas cold period 15k years ago.

Most scientists who have researched such things as a change in the thermohaline circulation say that fresh non salty water added to north atlantic has a good chance of destroying the “gulf stream” and its warming effect on the northern European climate – a tipping point. Do you have evidence that this cannot happen? Should this be discussed in a scientific way and not simply dismissed as alarmist?
Most scientists who have researched such things as the grounded sea ice round Antarctica have said that if this becomes ungrounded then its damming effect will be lost and the land based glaciers in Antarctica will speed up leading to higher sea levels – a tipping point. Do you have evidence that this cannot happen? Should this perhaps be discussed?
There is a large amount of methane hydrates stored in the ocean floors research shows that warming seas will release this to the atmosphere increasing the GHE – a tipping point. Do you have evidence that this cannot happen? Should this be discussed in a scientific way and not simply dismissed as alarmist?

23. Steven Mosher says:

“I have NEVER seen a so-called “tipping point” identified before it occurred. Nor do we have any understanding of what the leadup to a “tipping point” might look like.”

it might be more helpful if we discuss first what we mean by tipping point. Lets start with a agreed
upon defintion of tipping point.

Can you think of a system, Willis, that changes linearly up to a point and then changes non linearly when a threshhold is crossed? One example is the sandpile in catastrophy theory.
another example would be financial bubbles and collapse ( yup some folks predicted these)

The problem, as you hightlight, is that with tipping points everything looks normal and smooth
up to a point. Then POP.

yup sandpiles have landslides, and financial bubbles burst.

tell me you are not denying the existence of systems that look smooth and then collapse?

24. Steven Mosher says:

I love this alley video willis.

examples of tipping points. piles

25. Steven Mosher says:

Willis

“1) Defining just WTF you are talking about.

The best way forward on this is the example the artcle discusses
“Research in the past decade has shown that the Amundsen Sea embayment of West Antarctica might have passed a tipping point : the ‘grounding line’ where ice, ocean and bedrock meet is retreating irreversibly. A model study shows that when this sector collapses, it could destabilize the rest of the West Antarctic ice sheet like toppling dominoes — leading to about 3 metres of sea-level rise on a timescale of centuries to millennia. Palaeo-evidence shows that such widespread collapse of the West Antarctic ice sheet has occurred repeatedly in the past.”

So, WTF is ATTP talking about? Systems that suddenly and without certain warning, collapse.
See Alleys decription of spreading piles and flying butresses. What do we known from physics?
Glaciers act like spreading piles. They are held back from collapsing by friction at the grounding
Line. If that friction is lost, the “cathederal” collapses. This collapse will not be smooth. It will
be abrupt. Clearly you must recognize the POSSIBLITY of such a system? Clearly you
must admit that it is possible for a system to exhibit smooth change up to a point and then
non linear change. We know from paleo work that this region is subject to collapse.
That much you must agree to or folks will call you a physics denier or history denier.

2) Identifying a number of observations that would let us distinguish a turning point from a tipping point.

If it were that simple, seismologists could predict earthquakes. It’s clear that earth quakes
happen. Its also clear that the system can undergo smooth changes up to a point and then
POP. in fact the problem with tipping points is that you CANNOT simply predict them from
past data.. you look at a financial bubble and the prices go up nicely, then… POP.
So what do we know from studying past tipping points?
A) They EXIST. shit does collapse.
B) simple observation and simple data analysis ( statistical) is probably not up to
the task of predicting the collapse from past data. You need physical models.

So take earthquakes as an example of tipping points if you dont like climate ones

Are they real? yup
the plates slide slow,… and then BAM.
No looking at the dataseries will let you Predict the thing you know will happen.
weird.

In some ways Collapses DEMONSTRATE that your concept of science is wrong

fun video.

common sense gap

26. ecoquant says:

@Rob,

Atmospheric CO2 content is long-lived, so whatever is there presently will mostly still be there in another 100 years.

Rather,

Atmospheric CO2 content is long-lived, so [half] of whatever is there presently will mostly still be there in another 100 300 years[, and another half of whatever is there presently will be there in another 2000 years].

Them’s the facts.

27. Steven Mosher says:

There are no tipping points. There is no such thing as a small change causing a large effect.

These guys could not predict when an avalanche would happen. Therefore Avalanches
are not real. No one has ever predicted the onset of an avalanche PRECISELY, therefore
they can never happen. Avalanche warnings are useless since they just scare people un necessarily. You can’t specify the EXACT conditions when an avalanche will occur. Therefore
dont be concerned.

cool

Everyday these clowns put out a forecast based on a The guy who has a calibrated elbow.
OMG not science

somehow lives are saved. weird.

/sarc off

28. Mark Brinkley says:

If there was no danger of tipping points, then climate change would be perfectly manageable as it would essentially be predictable. So claims that we face a “climate catastrophe” are based pretty much on the threat of tipping points being breached. The problem with tipping points, as the avalanche metaphor highlights, is that they are unpredictable and indeed may not happen at all. All we can realistically do is the keep plugging away at the science, trying to build a more accurate model of where and when the tipping points are, that way reducing the uncertainty element. That’s not to ignore any mitigation strategies which act to reduce the overall risk.

29. Steven Mosher says:
December 1, 2019 at 3:03 am

I said:

“I have NEVER seen a so-called “tipping point” identified before it occurred. Nor do we have any understanding of what the leadup to a “tipping point” might look like.”

You replied:

tell me you are not denying the existence of systems that look smooth and then collapse?

This is why I ask people to QUOTE MY WORDS! I choose them carefully, and I did NOT deny the existence of such systems. That’s all you, and I’m sick of you misrepresenting what I’ve said.

w.

30. Steven Mosher says:
December 1, 2019 at 3:54 am

Willis

“1) Defining just WTF you are talking about.

The best way forward on this is the example the artcle discusses
“Research in the past decade has shown that the Amundsen Sea embayment of West Antarctica might have passed a tipping point : the ‘grounding line’ where ice, ocean and bedrock meet is retreating irreversibly. A model study shows that when this sector collapses, it could destabilize the rest of the West Antarctic ice sheet like toppling dominoes — leading to about 3 metres of sea-level rise on a timescale of centuries to millennia. Palaeo-evidence shows that such widespread collapse of the West Antarctic ice sheet has occurred repeatedly in the past.”

So, WTF is ATTP talking about? Systems that suddenly and without certain warning, collapse.
See Alleys decription of spreading piles and flying butresses. What do we known from physics?
Glaciers act like spreading piles. They are held back from collapsing by friction at the grounding
Line. If that friction is lost, the “cathederal” collapses. This collapse will not be smooth. It will
be abrupt. Clearly you must recognize the POSSIBLITY of such a system? Clearly you
must admit that it is possible for a system to exhibit smooth change up to a point and then
non linear change. We know from paleo work that this region is subject to collapse.
That much you must agree to or folks will call you a physics denier or history denier.

So we are NOT talking about tipping points, we’re talking about systems that “collapse” without warning. But that is far, far from a definition, Mosh. That’s an example that doesn’t distinguish what you’re talking about from say a system that kinda collapses but doesn’t, or a system that shifts to a new state without collapsing, or that cycles up and down …

Plus most folks claim that tipping points are irreversible, but you claim that they’ve happened repeatedly in the past. And you base this on the article, which references a study that … say what? No reference to the claim of past tipping points? True. Might exist, but most curiously, they put in lots of references but left that one out.

2) Identifying a number of observations that would let us distinguish a turning point from a tipping point.

If it were that simple, seismologists could predict earthquakes. It’s clear that earth quakes
happen. Its also clear that the system can undergo smooth changes up to a point and then
POP. in fact the problem with tipping points is that you CANNOT simply predict them from
past data.. you look at a financial bubble and the prices go up nicely, then… POP.
So what do we know from studying past tipping points?
A) They EXIST. shit does collapse.
B) simple observation and simple data analysis ( statistical) is probably not up to
the task of predicting the collapse from past data. You need physical models.

So take earthquakes as an example of tipping points if you dont like climate ones

Are they real? yup
the plates slide slow,… and then BAM.
No looking at the dataseries will let you Predict the thing you know will happen.
weird.

In some ways Collapses DEMONSTRATE that your concept of science is wrong

I asked for something to distinguish a tipping point from a turning point. In response, you say that seismologists can’t predict earthquakes … so what? I didn’t ask about predictability, I didn’t aske whether you could “Predict the thing you know will happen”. I simply asked for a definition differentiating a tipping point from a turning point.

In return, you give me personal abuse and handwaving.

Sorry, amigo, but if you’re trying to actually answer the questions of mine that you quoted, that was a massive fail.

w.

31. [Chill. I won’t ask twice. -W]

32. Steven Mosher says:

“This is why I ask people to QUOTE MY WORDS! I choose them carefully, and I did NOT deny the existence of such systems. That’s all you, and I’m sick of you misrepresenting what I’ve said.”

‘?’ is a question mark. I asked you a question

I will make it easy. Are there physical systems that have tipping points.

Next, describe what you mean by tipping point

33. Steven Mosher says:

“So we are NOT talking about tipping points, we’re talking about systems that “collapse” without warning. But that is far, far from a definition, Mosh. That’s an example that doesn’t distinguish what you’re talking about from say a system that kinda collapses but doesn’t, or a system that shifts to a new state without collapsing, or that cycles up and down …

A tipping point would be a collapse.

You seem to be struggling with the definition, But since you contrasted “turning point” from “tipping point” what di YOU mean when you used the term. Since you used it.

Essentially Willis for the sake of this discussion since the article discussed Glaciers collapsing
you can take Tipping point and Collapse to be very related.

As for shift to a new state ( cycles) NO this is not a tipping point or collapse.
think PHASE CHANGE. So when your solid cglacier becomes liquid.

Note some collapses are reverisble. hey just freeze the water again

34. Steven Mosher says:

“You really should first read the article we’re discussing, which says:

A model study shows5 that when this sector collapses, it could destabilize the rest of the West Antarctic ice sheet like toppling dominoes — leading to about 3 metres of sea-level rise on a timescale of centuries to millennia.

I’ll repeat it slowly for you to make sure you get it.

“A. model. study. shows.”

##############

yes. The existence of tipping points and systems that collapse make it hard for your kind of epistemology.

35. verytallguy says:

Amidst Willis’ foam-specked rants is a demand for definitions.

Happily the IPCC (AR5 Glossary) provides:

Tipping point
A level of change in system properties beyond which a system reorganizes, often abruptly, and does not return to the initial state even if the drivers of the change are abated. For the climate system, it refers to a critical threshold when global or regional climate changes from one stable state to another stable state. The tipping point event may be irreversible. See also Irreversibility. {WGI, II, III}

36. verytallguy says:

Probably the best non- climate example is an ignition process.

Consider slowly heading some fuel in air.

The system is stable up to a point where ignition suddenly becomes self sustaining (the auto ignition point).

The process is irreversible – subsequent cooling will not return it to its earlier state.

The most obvious climate example is the Greenland ice sheet, where the low temperature at the summit depends on tbe altitude, which depends in the thickness of ice (a few km). Clearly there is a point where with rising temperatures, a collapse ensures, which is irreversible due to the loss of altitude. As I understand it, the tipping point, with considerable uncertainty, may be as low as 1.5 degrees global temperature rise.

37. Mosh, I have no idea what you call a “tipping point” since you have not given us a clear definition. So I cannot answer your question as to whether such systems exist.

It seems that by “tipping point” you mean “sudden collapse” … and if that’s the case, yes, almost any system can collapse suddenly.

So what? By that measure, an earthquake could be called a “tipping point”, and you refer to that above … but what does it gain us to call an earthquake a “tipping point”? What extra understanding does it give us? Houses collapse. Are those “tipping points”? How about divorces? Tipping points?

I dropped something I was carrying the other day and it broke. Sudden and irreversible. Tipping point? Who knows, and who cares? What additional insight will I gain by calling me dropping something a “tipping point”?

Your other question is, what do I mean by a “tipping point”? Since they cannot be identified until after the fact, I don’t know that I’ve ever once written about them. Why do you think I asked for a clear definition that distinguishes them from turning points (which neither you nor anyone else has provided to date)?

Because I don’t have one.

So let me put forward my three questions again since they have not been even begun to be answered:

1) Define just WTF you are talking about, in such a manner that distinguishes it from similar phenomena like say turning points, or ordinary changes in a system.

2) Identify a number of observations that would let us distinguish a turning point from a tipping point.

3) Develop a list of what your criteria identify as climate tipping points through history.

To which I would add, what does it add to call something a “tipping point”?

Still waiting … the only place I hear about “tipping points” is in bogus climate “science”, and the only time I hear about “tipping points” is when climate alarmists want to scare me into action.

But as I said, without a clear and detailed definition, which I assuredly don’t have, it’s hard to even discuss this nonsense.

w.

38. And here’s an oddity I found when I looked for a definition … “tipping point” started out life as a racist term. From Merriam-Webster:

However, when tipping point first began to be employed in general use, it was almost entirely in reference to the propensity of white families to move out of an area when a certain percentage of the neighborhood was composed of black families. It served as a precursor of sorts to the phenomenon of white flight.

Some white parents may reluctantly accept integration to the extent of 10 to 15 per cent…. Exactly when the “tipping point” of white acceptance will be reached will depend upon the attitude of the individual white parent and upon the general white community attitude.

—Homer Bigart, The New York Times, 19, Apr. 1959

The percentage of minority occupancy that initiates a withdrawal of other tenants has been denominated the “tipping point.”

—University of Pennsylvania Law Review, Vol. 107, Feb. 1959

Then, at this “tipping point,” which varies considerably in different situations, the remaining Whites tend to abandon the area quickly.

—Spencer L. Kimball, Michigan Law Review, May 1960

He was told that he was welcome in Village Creek but not on Split Rock Road because his moving there would upset the delicate racial balance since Negro occupancy had already reached the tipping point which might turn Split Rock Road into a “ghetto,” if another Negro family moved i

n.
—Pittsburgh Courier, 10 Feb. 1962

Curious how life works out … before being used for alarmism in climate terms, it was used for alarmism in racial terms.

w.

39. Willis,
It appears that the problem isn’t that there isn’t reasonable definition for the term “tipping point”, it appears that you either can’t, or won’t, understand what it is. As I already said, you’ve got a fair amount of work to do before you would be able to convince that you’re actually serious about discussing the science. It would appear that you aren’t really willing to put the effort in.

40. verytallguy says:

Greenland:

We estimate that the warming threshold leading to a monostable, essentially ice-free state is in the range of 0.8–3.2 C, with a best estimate of 1.6 C.

https://www.nature.com/articles/nclimate1449

41. verytallguy says:

Willis. I have provided you with definitions, examples and predictions.

Quit whining, and engage sensibly, or just quit.

42. Mark,

If there was no danger of tipping points, then climate change would be perfectly manageable as it would essentially be predictable.

That does assume that we can manage to deal with the changes, even if they are predictable. It’s not obvious that this is true, especially when considering regions that aren’t particularly wealthy that may need to deal with quite substantial changes in the coming decades. I guess, the rest of the world could choose to help, but it’s not clear that this is what will actually happen.

43. verytallguy says:
December 1, 2019 at 8:25 am

The most obvious climate example is the Greenland ice sheet, where the low temperature at the summit depends on tbe altitude, which depends in the thickness of ice (a few km). Clearly there is a point where with rising temperatures, a collapse ensures, which is irreversible due to the loss of altitude. As I understand it, the tipping point, with considerable uncertainty, may be as low as 1.5 degrees global temperature rise.

I’m sorry, but if the process is “irreversible” then the ice sheet could never have formed. This is the type of hysteria surrounding “tipping points” that I am protesting against.

And since everything you say is true of an ice cube (clearly there is a point where with rising temperatures, a collapse of the ice cube occurs that is irreversible), again I fail to see how calling this a “tipping point” does anything but increase the FUD …

w.

44. Steven Mosher says:

So lets see if we can underfstand willis.

for definition an EXAMPLE works just fine. It’s called an exemplar.
The exemplar the article discussed was a collapse of one part of a system leading to the
collapse of the West Antarctic ice sheet. And the analogy is toppling dominos.
one falls and the rest follow, by physics. know physics.

The example is a good one because it involves a phase change. Solid ice becoming water.
Are all collapses phase changes? nope. That pile of sand that has a slide or avalanche is
still sand.

So we can probably agree that systems can collapse. And that before they collapse they
May reach a point of no return. Call this point of no return the tipping point. That’s the point
where if things continue as they are, reaching collapse is inevitable. Inevitable according
to the laws of physics. Once the flying buttress starts to crumble its only a matter of time
(unless you repair it) before collapse will happen.

The difficulty with things like cathedrals and ice sheets is we cant do the kind of experiments
you might want to do convingly determine an exact tipping point, a point of no return.
And so we have to rely upon our best known science, yes that involves models.
So we have a system that is changing over time, and at some point X, we can calculate that
inertia in the system will drive it to a state of collapse.

a simple analogy is driving your car very fast toward a brick wall. At some point you reach
point where no amount of braking force can keep you from slamming into the wall..
Or when you are landing a plane on the carrier and you hit the no/no go point. A point of no
return.

You seem puzzled that we would know this by modelling, by representing physics in code.
Its simple. sometimes we know things by modelling.

unless you are a truther

45. verytallguy says:

Willis, do try to think before committing to keyboard.

The process is irreversible in the sense that returning to pre industrial temperatures will not result in re growing the ice sheet.

But you know this, you’re just choosing to act dumb.

You have the definitions and examples. You can choose to engage or contribute to thrash around and look ridiculous. Up to you.

46. Willis,

I’m sorry, but if the process is “irreversible” then the ice sheet could never have formed. This is the type of hysteria surrounding “tipping points” that I am protesting against.

As VTG says, it’s irreversible in the sense that even if we were able to reverse what we had done (i.e., bring concentrations down to levels where the ice sheet used to exist) the ice sheet retreat would continue. It’s not irreversible in the sense that the ice sheet can never reform again. This is not such a tricky concept.

47. …and Then There’s Physics says:
December 1, 2019 at 8:32 am

Willis,
It appears that the problem isn’t that there isn’t reasonable definition for the term “tipping point”, it appears that you either can’t, or won’t, understand what it is.

There are lots of definitions of “tipping point”. I clearly wanted the definition that you use. I want to know what it is that YOU are callin a “tipping point” in this thread, not what random guy in the street calls it, so we can profitably discuss it.

As I already said, you’ve got a fair amount of work to do before you would be able to convince that you’re actually serious about discussing the science. It would appear that you aren’t really willing to put the effort in.

Oh, piss off with your unwarranted claims of scientific superiority. So I’m supposed to read your mind to figure out what you are calling a “tipping point”? Not possible when, as now, you seem to want to keep it secret.

So far you’re the one not serious about discussing the science. Let us know when you’re actually willing to put in the effort to define what you’re talking about and distinguish it from similar things. Because so far, all you’ve done is attempt to bite my ankles, and that public failure of yours goes nowhere.

w.

48. Willis,
People have explained what this means many times. For example, an irreversible retreat of the West Antarctic and Greenland ice sheets. In this context, irreversible means that even if we were to later reverse some of the warming, the ice sheet retreat would continue. It doesn’t mean that at no point in the future could these ice sheets reform.

49. verytallguy says:

Willis, I gave you the IPCC definition, though you could easily have found it yourself.

You don’t seem very interested in it but are still ranting about not having definitions.

Perhaps come back later. You appear tired and emotional right now.

50. …and Then There’s Physics says:
December 1, 2019 at 8:46 am

Willis,

I’m sorry, but if the process is “irreversible” then the ice sheet could never have formed. This is the type of hysteria surrounding “tipping points” that I am protesting against.

As VTG says, it’s irreversible in the sense that even if we were able to reverse what we had done (i.e., bring concentrations down to levels where the ice sheet used to exist) the ice sheet retreat would continue. It’s not irreversible in the sense that the ice sheet can never reform again. This is not such a tricky concept.

The same is true of an ice cube. If we take the temperature above freezing it will melt, and if we reduce the temperature it won’t reform …

Again, so what? How does this help us understand either the winter or the ice cube? If this concept is so useful, why doesn’t every description of an ice cube discuss the tipping point?

w.

51. Willis,

The same is true of an ice cube. If we take the temperature above freezing it will melt, and if we reduce the temperature it won’t reform …

Except that if you reduce the temperature to below freezing, the water will freeze again (and if it was in an ice cube holder, you might even reform the ice cube).

The reason that this is a topic worth discussing (with some, at least) is that some of these tipping points commit us to things that we can’t then avoid. Substantial sea level rise, for exampe, or the collapse of an ecosystem (coral reefs, Amazon rainforest). Hence, we may want to consider if we should do more to avoid such outcomes.

52. verytallguy says:

Back on topic, it seems to me at least, that tipping points in ecosystems are the hardest to consider.

How possible is it even in principle to predict such impacts?

The Nature paper mentions coral reefs, boreal forests and the Amazon.

But how many other ecosystems have potential tipping points as temperatures rise?

It seems unknowable. Anyone able to remove a little of my ignorance?

53. vtg,
Agreed, I think it is difficult to precict tipping points in some of these ecosystems and I would certainly be interested if someone who knows more could clarify what we think we do understand well.

Something I was thinking about when writing the post was how should scientists engage in discussing this. What do you do, as a scientist, if you start to realise that we could be driving the system towards some major, potentially very negative, changes, but that these are difficult to predict (both in terms of the conditions under which they would occur and the resulting impacts). Do you stick to things that you feel we understand well enough to quantify, or do you speak out even though our understanding is quite uncertain?

54. David B. Benson says:
55. Rob says:

@ecoquant
Thanks for the clarification.
I was trying to keep things simple as atmospheric CO2 adjustment (equilibration) times consequent to anthropogenic emissions are calculated to be well over 100 years (Archer et al., 2009; Joos et al., 2013; Lord et al., 2016), but CO2 “residency” times are less than a decade.
My point was along the lines of there being little chance that the amplication effect of present CO2 levels can be reversed any time soon, so the total energy in the climate system can only increase going forward (yes, in many thousands of years time there will be another glaciation cycle but that’s not handy to us!).
If we use your 300 years/2000 years spread of CO2 equilibration then even talking about a tipping point might be trivial.

56. dikranmarsupial says:

“I have NEVER seen a so-called “tipping point” identified before it occurred.”

pure comedy gold. How many significant changes have we seen in the climate that are irreversible on human-relevant timescales? None. Thus you haven’t seen any of them identified after it occurred either.

“In fact, we don’t even have a definition of a “tipping point” that reliably distinguishes it from say a “turning point” where for example things were getting warmer for a while but now they’re cooling down.”

err, yes we do. A tipping point is a turning point, but it is one that will be irreversible on human-relevant timescales.

“Not only that, we don’t even have an agreed-upon list of “climate tipping points” throughout history.

… Come back when you’ve solved those problems …”

are you saying there ought to be a scientific consensus on this before we need to take the idea seriously?

Right, I wrote that before going through the rest of the discussion to see how Willis responded. The answer is “with more empty rhetoric”:

“Until you do that you’re just playing with your dick and pretending you’re doing science. ” followed by “.Do you think you can bring yourself to set your nastiness aside and stick to the science?” No hypocrisy there then. And later “As to your bullshit claim that “I have no response”, while you may devoutly wish that were the case, in fact I simply and totally missed whatever massive issue you think I’m “ignoring”. Seems a fair amount of “nastiness” to me there as well.

“I’m sorry, but if the process is “irreversible” then the ice sheet could never have formed. This is the type of hysteria surrounding “tipping points” that I am protesting against.”

This is just pedantry. As the ice sheet did form, it is clear that “irreversible” didn’t mean absoulte irreversibility. If I have a bottle of helium and let the gas escape into the room, it would be ridiculous to say that the change was not irreversible because the gas could never have got into the bottle in the first place. Similarly it is not absolutely impossible that a random walk would not take the helium back in again – it is not impossible, just vanishingly improbable. When we are discussing climate, anybody with an ounce of common sense would interpret it is irreversible on human-relevant timescales.

“There are lots of definitions of “tipping point”. I clearly wanted the definition that you use.”

Evasion by pedantry. I suspect the *exact* definition will depend on the particular tipping point under discussion. How about “a substantial change in the climate system that will be irreversible on human relevant timescales”?

“Again, so what? How does this help us understand either the winter or the ice cube? If this concept is so useful, why doesn’t every description of an ice cube discuss the tipping point?”

Straw man. Nobody says every description of the climate has to involve tipping points. Have you read Schopenhauer’s “The Art of Always Being Right”? You do realise it was written so that we would recognise and reject rhetorical devices, rather than as a “how to” guide?

57. dikranmarsupial says:

BTW, the IPCC WG1 report has a glossary that contains a definition of a tipping point that seems quite reasonable to me, perhaps Willis hasn’t seen it?

58. mrkenfabian says:

David – I wouldn’t expect much investment in what is needed to support an electricity grid with very high levels of solar until it approaches high levels of solar; ie approaches a tipping point. In a nation with policy makers and energy industry incumbents resisting change it doesn’t get done until and unless it has to be done – until it is more expensive to not do it than to put up with the problems that complacency and lack of foresight and outright obstruction bring to the issue.

Having more solar than an inadequate grid can manage will inevitably be used (by those still resisting change) to argue against having high levels of solar – mostly people who don’t accept or don’t care about the climate problem.

To be fair, the expectation that solar would not be taken up in great amounts was widespread – due to an expectation that solar would remain prohibitively expensive; the crossing of price parity looks, in hindsight, like a tipping point that, whilst not entirely unpredictable, was not taken seriously, nor planned for.

59. Chubbs says:

Below is recent Science paper on the value of 1.5C and 2C targets with info on tipping points and quite a few outlined. They make vtg’s point:

“This also explains the observation of “tipping points” where the condition of a group of organisms or an ecosystem can appear “healthy” right up to the point of collapse, suggesting caution in extrapolating from measures of ecosystem condition to predict the future.”

https://science.sciencemag.org/content/365/6459/eaaw6974

60. David B. Benson says:

mrkenfabian — Yes, the drop in the price of solar panels has been astounding. Power planners have traditionally been used to gradual change, so solar PV but also wind turbines have A quite a shock to power planning.

In the case of Perth and the surrounding little grid, a 700 MW battery of 4 hours duration would, I opine, solve the impeding problem.

61. verytallguy says:

Dikran

“BTW, the IPCC WG1 report has a glossary that contains a definition of a tipping point that seems quite reasonable to me, perhaps Willis hasn’t seen it?”

https://andthentheresphysics.wordpress.com/2019/11/30/tipping-points-elements/#comment-166456

62. dikranmarsupial says:

Ah, that was indeed helpful. Did I miss his substantive response as well? ;o)

63. angech says:

ATTP
“we tend to focus more on what we think will probably happen and not enough on what might happen. Even though what will probably happen could be pretty severe, the low-probability, high-impact outcomes carry the greatest risk. So, I do think we should be talking more about the potential worst-case scenarios.
A lot of what is suggested about tipping points is quite speculative; it’s very difficult to quantify the actual likelihood of them being triggered. Also some (like ice sheet retreat) might still be quite slow and may not even be truly irreversible.”

Perhaps if we compare what we do with diagnosing patients and what scientists do with diagnosing climate science it might offer another perspective.
The first comment is that looking for low probability high risk diagnoses is definitely not the way things are done.
Talking about them is interesting but practically they are of little value.
Concentrating on them, worst case scenarios is bad for two reasons.
Missing the obvious diagnosis and treatment is one.
Second is that it can be very upsetting to the patient and their family to be scared about things that are very unlikely to happen.
Medico legally we can see this when you sign a consent to an operation.
Worst case scenarios have to be brought to the attention of the patient.
When done in a one size fits all manner people can become so scared that they do not go through with an operation they desperately need.

64. Joshua says:

Willis –

> Curious how life works out … before being used for alarmism in climate terms, it was used for alarmism in racial terms.

I lived next to a neighborhood that experienced white flight (of notable proportions – to the point where it is often referenced as an example of the phenomenon). In my immediate neighborhood, white flight didn’t occur – specifically because of actions taken by people who were alarmed by re repercussions of white flight. The bordering neighborhood remains almost entirely black. The neighborhood I lived in remains vibrantly integrated to this day.

Now you may not find the changes that took place alarming. That’s your right. But using polemics to describe those who were alarmed by white flight in their community, and hiding behind YOUR uncertainty about what the term might mean, won’t change the historical facts in the ground of what happened.

Its curious what people find curious about life.

65. Joshua says:

eco –
> It’s not just “uncertainty”, which is a pretty nebulous thing to most people: It might be stochastic uncertainty, but it can also be weighting sources telling them things with lower confidence (perfectly legitimate in a Bayesian approach), or it can be a perceived cost of action given embrace of a particular picture of the world.
I think I understood what you were saying there, and I agree. And it’s a good point. Just saying uncertainty is too broad. It’s useful to describe the kind of uncertainty and contextual factors.
> So it’s not just uncertainty and its complexities, it’s also things like lags and tradeoffs. It is natural to think people are sufficiently familiar with these in these day-to-day to understand them, but using them, and packaging them into conceptual with the ability to reason with them with facility are two different things.
So then yes, I agree.
> Frankly, dealing with climate policy concepts, as well as environmental policy and a whole plethora of policies from health risks to crime to education demands numeracy as a skill, let alone logic.
But I think it depends on more than that. It also depends, imo, on a kind of humility and an internal mechanism that enables someone to not be intimidated by uncertainty – understanding that uncertainty is a constant and that elimination of uncertainty is an illusion. It also takes an experiential familiarity with accepting uncertainty.
> And these aren’t as plentiful as they should be. One can quibble about why — modern media has a big role, I think — but their absence basically means the public are ill-suited to reasoning about and choosing these things.
I think here, perhaps you are underestimating the influence of certain inherent attributes of human psychology.
> It’s not their fault. But it not being their fault won’t protect them from the consequences of poor choices. That’s hard news. But we can try to persuade, rhetorically and economically.
I think that more is needed than persuasion

66. Greg Robie says:

Are not “probably” and “might” a duality that is a professional hazard?

For example, if one frames this post’s ‘validity’ question relative to the area of academic study that is currently the modeling results that are out of sync with observations (significantly invalid), one will be talking the Arctic cryosphere. Such ‘invalid-ness’ is explicitly not included in the “no committed warming” assertion in the IPCC Special Report on 1.5°C.

Where the models say the biggest shift in temperature is predicted to happen first is also where the predictions lag the observation by [currently] the greatest amount. And, isn’t this truth self-evident: professional scientific academics LOVE to give each other metaphorical wedgies over the difference between these to terms? If so, where a “probable” has – and so far – ever increasing become an unlikely “might,” is plausibly a best frame of reference to use for addressing this post’s question of how to avoid valid criticisms: the Arctic’s cryosphere.

For example our planets’ most skilled Arctic [extra-academic/professional] observers’ generational observations regarding seasonal shifts in atmospheric refraction is “might”, as opposed to “probably”, while concurrently being confirmed by the current Svalbard SOUSY radar data. As that SOUSY data set grows to be thirty years in length, what is, by scientific convention, a “might” can increasingly become a “probably” (with the [academically] requisite of error bars).

In the meantime the “deplorable” extra-academic savant-like Arctic observers knowledge lies forgotten/dismissed in plain sight; lacks [academic] validity!

Over our family’s recent Thanksgiving gathering, I attempted, as I have here at ATTP, to communicate the sourse of the unmodeled heat gain the Arctic crysophere observations reveal concerning what models predict. I had limited success in communicating a summary of what I’ve shared in this blog’s comment stream with two of my three relatives with advanced degrees in science. The older of the two, about a decade older than myself, volunteered that she has, during her retirement years (when she had the requisite time to observe) observed a shift in where the sun rises here in the mid-latitudes on the summer solstice relative to a tree viewed from here kitchen window. We discuses the noise concerning different atmospheric pressures within high pressure cells that would contribute to this observed shift. And this was in the context that our warming atmosphere is lifting the tropopause everywhere. Ironically (but for motivated reasoning!), the idea that the shift in the earth’s magnetic pole, such having been among the things I had talked about in my framing of the conversation, became a factor she said she felt was in play.

Or, explaining away terrifying news is something that motivated reasoning is highly skilled at accomplishing.

I have, to little avail, attempted to point our to host here at ATTP how he might be challenged to observe his trusted motivated reasoning. The equivocating, which I see as integral to this post’s framing, is another example … and allows me another attempt.

• “if we fail” is also “we have failed” … & what follows are reasoned statements that are “possibly” impertinent. • “if we are unlucky” re “convoluted” is also a red flag for motivated reasoning and magical thinking. • “if we do start to limit our emissions” is also, given the decade lag in the methane to carbon dioxide transition, a “we are…”. Aren’t anthropogenic carbon dioxide emissions declining? The tabling in methane emissions, in conjunction with the decade lag, plausibly explains the mid-teens stability in CO2 emissions. Subtract the decade-ago increase in CH4 emissions from the current atmospheric carbon dioxide levels, and a different framing of some conversations seems merited. • “all the uncertainties” is also “all the certainties motivated reasoning masks”. • “how do you avoid simplifying it” is also – & simply (paraphrasing Voltaire) – if [criticism] did not exist man would need to invent it! 😉

And this is why, to communicate what science “possibly” knows, it “might” be necessary for academia to collaboratively affect a zero carbon business plan by 2025?!?

=)

sNAILmALEnotHAIL …but pace’n myself

life is for learning so all my failures must mean that I’m wicked smart

>

67. Joshua says:

Eco –

Ironically, I am just reading L. J. Savage’s 1951 paper on “The theory of statistical decision”, cited by Elizabeth Baldwin in the paper I linked above. Not too far into the paper Savage writes:

> Traditionally, the central problem of statistics is to draw statistical inferences, that is, to make reasonably secure statements on the basis of incomplete information. This entails other problems, particularly that of designing experiments which permit the strongest inference for the expenditure involved. The new theory under discussion, however, centers about the problem of statistical action rather than inference, that is, deciding on a reasonable course of action on the basis of incomplete information. There is clearly an abundance of situations calling for statistical action.

Ironically, ironically, I was just yesterday taking with my brother, who is a professor of signal processing, about the difference between price and cost, and he talked about how in statistics, something like “cost” is a part of evaluating probabilities (e.g., the probability of identifying cancer vs. the probability of false positives).

68. Joshua says:

Dear blog God –

Hmmm. Somehow line breaks between my excerpts of what eco said (marked by a “>”), and what I said in response, were lost in the into/out of moderation process in my 2:38 pm comment?

Weird.

69. Joshua,
That’s quite a lot of fixing to do. Do you have a backup that you could post again?

70. Joshua says:

Anders –

Didn’t mean to suggest you might fix it – only commenting on the oddness of it. That said… let my try reposting to see what happens (won’t it wind up in mod again?) :

……………………
eco –

> It’s not just “uncertainty”, which is a pretty nebulous thing to most people: It might be stochastic uncertainty, but it can also be weighting sources telling them things with lower confidence (perfectly legitimate in a Bayesian approach), or it can be a perceived cost of action given embrace of a particular picture of the world.

I think I understood what you were saying there, and I agree. And it’s a good point. Just saying uncertainty is too broad. It’s useful to describe the kind of uncertainty and contextual factors.

> So it’s not just uncertainty and its complexities, it’s also things like lags and tradeoffs. It is natural to think people are sufficiently familiar with these in these day-to-day to understand them, but using them, and packaging them into conceptual with the ability to reason with them with facility are two different things.

So then yes, I agree.

> Frankly, dealing with climate policy concepts, as well as environmental policy and a whole plethora of policies from health risks to crime to education demands numeracy as a skill, let alone logic.

But I think it depends on more than that. It also depends, imo, on a kind of humility and an internal mechanism that enables someone to not be intimidated by uncertainty – understanding that uncertainty is a constant and that elimination of uncertainty is an illusion. It also takes an experiential familiarity with accepting uncertainty.

> And these aren’t as plentiful as they should be. One can quibble about why — modern media has a big role, I think — but their absence basically means the public are ill-suited to reasoning about and choosing these things.

I think here, perhaps you are underestimating the influence of certain inherent attributes of human psychology.

> It’s not their fault. But it not being their fault won’t protect them from the consequences of poor choices. That’s hard news. But we can try to persuade, rhetorically and economically.

I think that more is needed than persuasion

71. angech,

Perhaps if we compare what we do with diagnosing patients and what scientists do with diagnosing climate science it might offer another perspective.

There is one major difference between diagnosing patients and diagnosing climate science. Doctors see many patients, so it often makes sense to make the obvious diagnosis rather than assuming that the symptons are indicative of something rare and unusual. This can be unfortunate if one patient does indeed have the rare and unusual illness, but it would typically be more harmful to scare lots of patients with extreme diagnoses just in order to not miss the rare occasion when this would be correct. In the case of climate science, there is only one planet/climate.

72. Willard says:

> I have no idea what you call a “tipping point” since you have not given us a clear definition.

Very Tall gave you one, dear Willis. He repeated it many times. Next time you want to play Socrates, please check with the official source first.

73. Why doesn’t the Map vs. Territory problem receive a bit more attention/discussion? Why not more exploring of how each of us views (and communicates) physical reality?

After all it is what’s behind this rhetorical game Willis plays at so well.

Seems to me fundamentally Willis is claiming that unless it can be explained to everyone’s satisfaction, it can be disregarded. Reading through Willis’ text I’m more’n more struck with the metaphor of a guy tossing out bones for the dogs to dutifully run after and fetch.

It’s like there’s a base assumption that physical reality depends of what we can construct within our human ‘mindscape’ – rather than openly acknowledging that physical reality is the ultimate touchstone that it is we are tasked with trying to understand as best we can.

Why not dissect Willis’ rhetoric the way they do with football games and stuff?

74. This is an entertainingly absurd thread that is a thousand miles away from the discussions about phase transitions, critical points, and Ising models that I had while in graduate school. Willis is apparently trying to emulate the late Per Bak, the originator of the sand-pile criticality model, who was quite the character

Faced with many skeptics, Dr. Bak pursued the implications of his theory at a number of institutions, including the Brookhaven National Laboratory in Upton, N.Y., the Santa Fe Institute in New Mexico, the Niels Bohr Institute in Copenhagen and the Imperial College in London, where he became a professor in 2000.

He took his ideas to a general readership in 1996 with his ambitiously titled book “How Nature Works.”

“He was the most American of Danes,” said Dr. Predrag Cvitanovic, a professor of physics at the Georgia Institute of Technology in Atlanta. “Danes eschew confrontation, but he was arrogant and loved to fight with his colleagues in academia. We all have stories of how we first met him, usually remembered by some outrageous statement or insult.”

75. I like the Baldwin idea: “Baldwin, in particular, offers a clever decision theory under incomplete information where actions are preferred if they optimize over all possible “tastes and beliefs”. Accordingly, an action is deemed good and recommended if, no matter what the tipping points we are approaching or not, outcomes and means appeal to everyone’s interest.”

I think that discussion of tipping points, their potential impact and timing makes a lot of folks go crazy. That happens even though there are many actions that can be taken to significantly reduce the dangers and impact in ways that these same folks are likely to accept and find beneficial.

Clearly and carefully discussing tipping points is quite likely to make some crazy, as this post and ensuing comments show. I wonder if inserting language on risk management as a focus would help these same folks relate better to the discussion?

Cheers,

Mike

76. Joshua says:

angech –

> The first comment is that looking for low probability high risk diagnoses is definitely not the way things are done.

As Anders touches on above – relying on high probability risk also suggests a parallel problem.

I have hypertrophic cardiomyopathy. One time I had knee surgery. Back home during recovery, I started getting very short of breath. High probability is that I need to clear out my system from the surgery. The out of breath got worse. I went to the hospital, my pulse ox was 81. They admitted me and did a ct scan. They found my lungs congested. The high probability diagnosis was pneumonia. The pulmonologist put me on high dose antibiotics.

The next night, when I was still on oxygen, the infectious disease doctor came in and said he’d been looking at my case, and he started asking me many questions. After 15 minutes of that, he said that I didn’t have pneumonia – but that I was in heart failure. He took me off the antibiotics and put my on Lasix. Within a few hours my pulse ox was normal. (Side story, the infectious disease doc was British and the pulmonologist was Indian. When the pulmonolgist heard that I had been taken off the antibiotics, he criticized the Brit – saying “Those Brits always think they know better than anyone else.” I was caught in a post-colonial medical battle.

At any rate, sometimes looking at the low probability diagnosis is exactly what you want, rather than falling into the trap of thinking inside the box and just reflexively going with the high probability diagnosis..

> Talking about them is interesting but practically they are of little value.
Concentrating on them, worst case scenarios is bad for two reasons.
Missing the obvious diagnosis and treatment is one.

See above, and Anders’ response.

> Second is that it can be very upsetting to the patient and their family to be scared about things that are very unlikely to happen.

Upsetting the patient is one of the factors that needs to be weighed in. One needs to consider that, say, when you do a cancer screen or a genetic screen. But you don’t just reflexively ignore high probability risks simply out of fear of scaring the patient.

> When done in a one size fits all manner people can become so scared that they do not go through with an operation they desperately need.

Who is suggesting one size fits all?

77. Joshua says:

er…But you don’t just reflexively ignore high low probability risks simply out of fear of scaring the patient.

78. Willard says:

> Why not dissect Willis’ rhetoric the way they do with football games and stuff?

Great idea. We need a name for that kind of thing. How about ClimateBall?

Fame and fortune awaits us!

79. I don’t think the medical patient is a particularly good analogy. It might make better sense to think about risk management in the way we build infrastructure to avoid catastrophic collapse in the low probability, high impact event. I think planning around the possibility of climate catastrophe is more akin to the way we plan buildings to withstand the “big one.” That seems less scary than the medical analogy.

80. morpheusonacid says:

[You’ve been warned twice, Allan. -W]

81. morpheus,
That isn’t the definition of a tipping point in this context. As VTG has already pointed out

Tipping point
A level of change in system properties beyond which a system reorganizes, often abruptly, and does not return to the initial state even if the drivers of the change are abated. For the climate system, it refers to a critical threshold when global or regional climate changes from one stable state to another stable state. The tipping point event may be irreversible. See also Irreversibility. {WGI, II, III}

82. ecoquant says:

@Willis Eschenbach, and anyone interested,

The origin of “tipping point” comes from dynamical systems studies, although the term has been picked up by colloquial discourse and is sometimes stretched. I do not know if specific fields like geophysics or meteorology have any more specific definitions. Michael Ghil is a well known dynamicist, and he often works on geophysical and climate problems, addresses the disambiguation of the term in a famous talk he gave in 2012 (see slide 2). The definitive is apparently Lenton, Held, Kriegler, Hall, Lucht, Rahmstorf, Schellnhuber(2008) and they give a formal definition of both tipping element and tipping point in their Appendix 1, and they widen the definition to include things other than dynamical bifurcations.

Let’s put something aside right away … Tipping points are often predictable. See

F. Nazarimehr, S. Jafari, S. M. R. Hashemi Golpayegani, M. Perc, J. C. Sprott, “Predicting tipping points of dynamical systems during a period-doubling route to chaos“, Chaos: An Interdisciplinary Journal of Nonlinear Science (2018), 28(7), 073102,

and

J. Jiang, Z.-G. Huang, T. P. Seager, et al, “Predicting tipping points in mutualistic networks through dimension reduction“, PNAS, 2018.

A menu of climatic tipping elements has long been available. Also, tipping elements are present in geophysics which are not directly related to climate but have been studied and are also predictable.

Reading around these articles suggests that climate tipping elements and points should not be dismissed. Lenton and Ciscar wrote in 2013:

In particular, there are multiple potential tipping points and they are not all low probability events; at least one has a significant probability of being passed this century under mid-range (2–4 °C) global warming, and they cannot all be ruled out at low ( 4 °C) or very high (> 8 °C) global warming. This discrepancy could qualitatively alter the predictions of IAMs, including estimates of the social cost of carbon.

Lenton (2010) gave a review of possible tipping elements and points, along with an assessment of their likelihood:

The possibility of unwitting commitment to a Hothouse Earth was recently examined in

Steffen, Rockström, Richardson, Lenton, et al, “Trajectories of the Earth System in
the Anthropocene
“, PNAS, 2018.

And, of great interest to me, there is a Nature Climate Change letter by Lenton and other which argues climate emergencies do not justify engineering the climate, meaning solar radiation management:

Sillmann, Lenton, Levermann, Ott, Hulme, Benduhn, Horton, “Climate emergencies do not justify engineering the climate“, Nature Climate Change (commentary), 2015

where:

* For slowly evolving tipping points, by the time the state change is recognized, it is too late to do anything. They cite the disintegration of the WAIS as having been already committed to in the last 20 years, even if it will take a couple of hundred to fully realize.
* For rapidly developing tipping points, such as shifts in monsoons, because these are spatially localized, responding to them with a global measure like SRM poses threats to the world, and is not likely to help the locale.

Thus, Sillmann, et al conclude

.. [T]he potential for SRM to respond effectively to tipping-point ‘emergencies’
is very restricted. Even if there were a case where it could be a logical response, there is one final problem: decisions on how much SRM to implement would have to be based on experiments with the same global climate models that had failed to predict the occurrence of a tipping point in the first
place.

83. ecoquant says:

By the way, Steffen, et al (2018), contains a really nice figure (their Figure 2) of a hypothetical dynamical landscape which could lead to a Hothouse Earth.

Note Hothouse Earth is not the same as a runaway greenhouse effect, per Venus. It is a state akin to the extreme warmth of the Mesozoic.

Also, Steffen, et al, introduce the idea of a tipping cascade whereby rapid evolution crossing a tipping point sets up the activation of a second and, then, transitively, a third, and so on. This is particularly feasible in a world where emissions continue unabated.

84. It sounds like hothouse earth state would allow us all to save money on winter heating costs! Much the same way that increased CO2 in the atmosphere is really great for growing vegetation. Silver linings!

85. ecoquant says:

@smallbluemike,

🙂

Except we’re not really evolved to survive during such conditions. Hanna, Tait (2015). The tropics would need to be evacuated. And that’s a thing … When people say “Earth has seen these kinds of climates many times before”, while that is narrowly true, it doesn’t mean people could survive then. This isn’t limited to temperature either. I believe the high Oxygen content of the Permian was not an environment where people would have done well: Oxygen can be toxic in sufficiently high concentrations.

86. [My suggestion was quite compulsory, Willis. -W]

87. ecoquant says:
December 1, 2019 at 8:18 pm

@Willis Eschenbach, and anyone interested,

The origin of “tipping point” comes from dynamical systems studies, although the term has been picked up by colloquial discourse and is sometimes stretched. …

Thanks, ecoquant, that was very much what I was looking for. It will take a while to work through all of it.

w.

88. David B. Benson says:

I am under the impression that the tropics won’t warm much but rather become broader:

89. ecoquant says:

@Willis Eschenbach, and all,

Because the definition is (apparently) so critical to this discussion, especially since it seems to be a point of common consensus, it’s worthwhile to share it with everyone. I have done that below.

Where it ends is interesting, because W.E. is kind of correct in that it is difficult to see a tipping point coming, at least with sufficient lead time to be able to avoid it. But the proper inference is quite the opposite of what W.E. argues. Claiming that tipping points are happening is not an alarm to change in order to avoid them, but, rather, that they are approaching and irreversible, but there may be others if we don’t change. Lenton, et al (2008) argue it is precisely the inability to see tipping points coming soon enough to avoid that is the key motivator for immediate and rapid decarbonization.

90. ecoquant says:

@David B Benson,

Re: tropics not warming much …

I can’t see how that could happen, because the rest of the planetary atmosphere will surely warm, and that’s an unsustainable state unless there is some process keeping atmosphere thermally stratified. What does make sense is that the Hadley weakens as it expands and, in a possible unrealizable limit, collapses and stops.

That said, it’s not clear there are good constraints on what’s going on here. Dr Paul Pukite (@WebHubTel) may be able to shed some light.

91. ecoquant says:

@Willis Eschenbach,

[Snip. -W]

You are confounding different meanings of “seeing something bad coming”. You can know that there’s a tipping point out there without knowing quantitatively what the trigger value $\rho_{crit}$ is. Accordingly, if it exists and if, by some argument bounding $\rho_{crit}$ it looks like you’re getting close, it is a good idea to be prudent. See above if you don’t know what $\rho_{crit}$ is.

So, for instance, referring to Steffen, et al (2018), +2C warming is estimated to be the rough place where we might collectively commit to a Hothouse Earth. Is it exactly +2C? Probably not. It could be a bit smaller or it could be a bit larger. The logic is that given Hothouse Earth outcomes are bad and irreversible (read Steffen, et al), it might be a good idea to avoid that part of the space altogether.

92. Willard says:

Stop addressing Willis, ecoquant. He’s baiting you.

93. David B. Benson says:

It was certainly warmer during the
https://en.m.wikipedia.org/wiki/Miocene
and yet proto-humans thrived in the African tropics. So I doubt that the tropics will become unlivably warm.

94. ecoquant says:

@David B Benson,

Modern people are not the same as “Miocene people”. Certainly the morbidity associated with recent heat waves is not promising. Read the setup in the Hanna and Tait (2015) paper I linked.

And, by the way, the lack of warming at the tropics despite forcing is partly because of how the present day lapse rate works — or, rather, doesn’t — at the tropics. Should that change …

95. Jan said:

“That said, it’s not clear there are good constraints on what’s going on here. Dr Paul Pukite (@WebHubTel) may be able to shed some light.”

Thanks for the ref. It appears that natural variability is playing a role. I haven’t explored the mid-latitudes too much as I don’t think there are enough constraints to simplify the models (as of yet).

96. David B. Benson says:

As genus Homo shares 99% of genes with chimpanzees, we can be quite sure that the basics have not changed since the Miocene.

None of the heat wave deaths of which I am aware are from the tropics.

I will stick with what I learned from studying “Principles of Planetary Climate” by Ray Pierrehumbert.

97. ecoquant says:

At least one study suggests the onset of deep convection shifts to higher temperatures with additional forcing, something which frees tropics of a thermostat-like constraint: https://rdcu.be/bX5mf

98. [#ButCAGW -W]

99. David B. Benson says:

eqoquant, that is distilled in Pierrehumbert’s most excellent textbook. And I don’t claim anything for how well humans would do in Eocene-like conditions!

100. angech says:

Joshua
“Side story, the infectious disease doc was British and the pulmonologist was Indian.”
From an Australian perspective my first thought would have been a pulmonary embolism needing a Spiral CT pulmonary angiogram or a VQ scan.
Not an issue since you have recovered.
Pneumonia should have had high temp and raised ESR and white cells.
Sometimes it is worth doing tests to exclude underlying clotting problems like factor V Leiden for future reference

101. izen says:

@-angtech
“Medico legally we can see this when you sign a consent to an operation.
Worst case scenarios have to be brought to the attention of the patient.”

It is not just a legal requirement.
It is not possible for a person to give informed consent to a procedure unless the worst case scenario, including its rarity, is understood.

In some cases it may be inherently unpredictable how likely or otherwise a significantly negative outcome is to occur.
But that INCREASES the need to apply the ‘precautionary principle’ and fully consider all possible and not just probable outcomes.

The way in which clinical consent and decision making is approached may give an indication of how the rare, unlikely, but very negative impacts of climate change should be dealt with.

102. Well, in case you weren’t already terrified by tipping points, nine more have been identified. And not only that. These have been identified by SCIENTISTS … and guess what?

It is Worse Than We Thought™.

Scientists warn world is approaching climate tipping points

Everyone Panic!!!

w.

103. Willis,
Given that the suggestion is not that people should be terrified, or that people should panic, it seems clear (as I was indicating in one of my first responses to you) that you are not engaging in good faith.

104. izen says:

@-Eschenbach
“Everyone Panic!!!”

In the clinical field the identification of serious negative impacts, irreversible damage, requires rational, informed decision making.
Perhaps the same is indicated in response to the increasing high risks associated with the ongoing cumulative CO2 emissions.

105. [Mod: You’re not even trying to engage reasonably.]

106. Joshua says:

angech-

> Pneumonia should have had high temp and raised ESR and white cells.

That’s part of my point. The pulmonologist saw an image of gunk in my lungs and went to pneumonia because that was the well-worn, high probability groove that fit with his expectations. He also overlooked the relatively short time frame for pneumonia to develop.

107. AndyM says:

To give some context to Willis’s contribution, back in 2013 he was keeping an eye on snow extent because he was wondering if an Ice Age was on its way.

108. David B. Benson says:

Pro forma.

109. JCH says:

If you’re a doctor in North America and you hear hoofbeats, you don’t think “zebras!”.

My nephew presented with array of odd symptoms. Dozens of visits to the ER and doctor’s offices. When it was way too late, he was one of around 200 people per year worldwide diagnosed with a rare liver cancer: fatal. The above was the excuse. He did not make it to 30.

110. verytallguy says:
111. angech says:

The second element to remember is that not all tipping points are bad. While it is also very unlikely perhaps a verdant world awaits the truly skeptical. A (warm) land of milk and honey overrun with happy herbivores and lush grasses just dying to feed the hungry hordes of modern humanity basking in Eden. Lysis or crisis.
Ok only joking but why do all tipping points have to be bad?

112. Joshua says:

> . So … would it not be truly ironic if pollution, in the form of soot and brown carbon, were all that has been holding off another ice age? And wouldn’t it be a cosmic joke if our efforts to clean up soot and brown carbon pollution were the straw that broke the back of the Holocene, and ushered in the new ice age?

Tipping point?

113. ecoquant says:

@angech,

Ok only joking but why do all tipping points have to be bad?

* Bad/good is rating something on a 1-dimensional scale. Not all systems have dominant behaviors which can be mapped onto a single dimension. Many can have their behaviors mapped onto a handful of dimensions. But for any $d$-dimensional one, with $d > 1$, it isn’t possible to form such a total ordering. So it’s not so much bad/good as varied.
* One way of managing the mapping is to define the 1-D scale in terms of some goodness criterion for a specific variety of a specific biological species, setting aside the implications for other biological species. (Admittedly even for a single variety this could be challenging, as there are many criteria that might want optimization.) In principle, by this definition, some tipping points could be “good”.
* From an engineering perspective, if, say, a tipping point could be forced to happen, in order to optimize something like the (immediate) above, enough of the climate state or substate would need to be known (“observable”) in order to evaluate the criterion. A characteristic of such climate states, certainly in the subset of tipping points which are bifurcations, is that we have little experience of what they are like. There are paleoclimates which have left various records which can be used to estimate some of these, assuming those states can be properly associated with the one sought. But we can’t be sure. So, one might progress towards a tipping point and force it, but what might seem good might not be, and, given that these are all of lower “potential energy” (see the figure from Steffen ,et al above), once there you can’t go back.

114. dikranmarsupial says:

angech “Ok only joking but why do all tipping points have to be bad?”

This kind of thing has been explained to you often enough. Our civilisation (and particularly our agricultural practices) are adapted to our pre-industrial climate. If we change that climate we will have to change some of our practices, and that will involve costs. For a tipping point to be a good thing would require the benefits of that change to exceed the costs of the change in practices. That means that most change, including tipping points, will be more likely to be bad than good.

Nobody says that all climate change is bad for everybody, that is just a stupid straw man that skeptics use to avoid the possibility of constructive discussion.

115. dikranmarsupial says:

There is also the point that if the benefits that I accrue from fossil fuel use are greater than the disadvantages experienced by someone else as a result, does that justify my use of fossil fuels? That is an ethical question, not a scientific or economic one (and the answer of course is “no”, unless you view yourself as in a privileged ethical position such that the golden rule does not apply).

116. Joshua says:

angech –

> While it is also very unlikely perhaps a verdant world awaits the truly skeptical. A (warm) land of milk and honey overrun with happy herbivores and lush grasses just dying to feed the hungry hordes of modern humanity basking in Eden.

To riff a bit off of eco and dikran…

I see it as, in part, a matter of the extremes of the positive and negative costs and benefits.

We might weigh the upside of milk and honey for everyone relative to the current norm, versus the downside of making some currently inhabited sections of the planet virtually uninhabitable and other sections into places where life is only sustainable at significant cost.

In such a frame, milk and honey would be less “better,” imo, than the latter scenario would be “worse.” Of course, that is a subjective evaluation. Someone closer to the margin of sustainability now than I am might evaluate those relative changes differently. And of course, you’d then have to put those assessments into an assessment of the relative likelihood of extreme change in either direction, respectively.

Or, you can just throw up your hands and repeat “uncertainty, uncertainty, uncertainty,” and maybe throw in a few pejoratives like “alarmist” for good measure. When faced with complicated questions, rants of righteous indignation surrounded by gorilla dust seems to be a good way to steer through for some people.

117. Willard says:

> Everyone Panic!!!

118. Chubbs says:

We don’t have any experience with climate tipping points and unfortunately our 0—>1C experience isn’t very instructive.

119. “There is also the point that if the benefits that I accrue from fossil fuel use are greater than the disadvantages experienced by someone else as a result, does that justify my use of fossil fuels? That is an ethical question, ”

It’s a very old ethical question. Some solve it by sharing their fish, some by teaching people how to fish, and a very few by eschewing fish and living in a mountaintop monastery. The most ethical response to fossil fuel question is to seek viable, cost effective alternatives. The least is gluing oneself to public transportation to call attention to the dream of a world without the benefits of energy.
Are our universities focused more on producing the people who will design and build electric cars, or the people who will block the roads? The answer to that helps us understand how seriously we all take the question.

120. Willard says:

Very Tall,

It might be instructive to construct a taxonomy style and substance and compare to the typical self-styled sceptic (Chic, are you still here?). Calling Willard.

https://andthentheresphysics.wordpress.com/2014/07/08/we-need-a-better-class-of-climate-skeptic/#comment-26370

Here would be a start:

https://andthentheresphysics.wordpress.com/2019/11/12/contrarian-models/

Constructive criticism goes a long way with me.

121. Joshua says:

> Some solve it by sharing their fish, some by teaching people how to fish…

Some solve it by propping up fascistic autocracies, that deprive many in their citizenry basic human rights, so the flow of oil can remain constant – no matter the negative impact to people other than themselves.

> The least is gluing oneself to public transportation…

Damn hippies

> … to call attention to the dream of a world without the benefits of energy.

I certainly know the last time I took the subway it was to dream of a world without the benefits of energy.

122. Joshua says:

Jeff –

> Are our universities focused more on producing the people who will design and build electric cars, or the people who will block the roads? The answer to that helps us understand how seriously we all take the question.

Rhetorical questions can prove useful. Sometimes they reveal someone who seeks to obscure his ideological activism behind a veil of “help[ing] us understand.”

I’m just curious if you might be leaning in a particular direction w/r/t the answer to your question about our universities? I think I might have detected a hint you lean in a particular direction iyour answer, which might suggest your question is of the revealing rhetorical type – but I can’t quite be sure.

See what I mean about the use of rhetorical questions?

123. KenH says:

Jerry Mitrovica has done some work on ‘local’ gravitational effects near ice sheets and grounding lines in Antarctica. First video at about 47:30

https://climatechange.environment.harvard.edu/jerry-mitrovica

124. KenH says:

May affect the rate at which the “tipping” occurs.

125. ecoquant says:

@Joshua,

This is about decision making and statistics, signal detection theory, and all that, responding (finally) to the comment here. I deferred responding, since the response is a bit involved, but am ready now.

First, completely besides my own response, and just for general awareness, as an alternative to ROC, meteorologists and, actually, some machine learning experts, use Brier Score as an assessment of skill. This is pertinent because skill as assessed by Brier Score is only assigned when there actually is value-add on the part of the predictor: A prediction simply consistent with the prevailing likelihood in a population has a Brier Score of zero. This pertains to the relative performance of the two medical diagnosticians in the case offered above.

Second, on to my view:

If any of my scribings here are unclear, there is a pretty good treatment in an online book by M. Clyde, M. Cetinkaya-Rundel, C. Rundel, D. Banks, C. Chai, and L. Huang. Also, my understanding of signal detection from the literature is that the approach I sketch is normative there today as well.

From a Bayesian perspective, inference and estimation are, to use the words of Professor Kruschke of Indiana State University, “the reallocation of credibility among possibilities”. Accordingly, the observation of data with an experiment does not produce a statistic, sufficient or otherwise, but, rather a function, the posterior distribution. Similarly, if the matter at hand is making a decision, the objective of the corresponding Bayesian exercise is to minimize expected posterior loss across a distribution or spectrum of possibilities. This involves introducing a loss function, meaning cost as a function of system parameters. It also involves coming to the table with a prior in hand, which is a function assigning probabilistic mass to the same range of possibilities. This might be informed by previous experiment, by ab initio calculations, by expert testimony, by previous Bayesian estimations, or some weighted combination of these.

Given realistic distributions among possibilities for complicated systems, it’s entirely likely the posterior loss function is multimodal. This is not a consequence of Bayesian inference but of the complexity. Engineered systems are often designed so this kind of thing seldom happens, because they don’t want to deal with the multimodal optimization. They also like Gaussian distributions, and develop systems which behave this way. In ecology and environmental work, and geophysics, this may not be the case. In these cases to minimize expected posterior loss might mean something quite different than finding the least value of the corresponding system, and there are a range of choices. For example, external regret might be chosen, where the “plays” are instead of game choices each of the multiple local minima in the posterior loss.

This posterior loss is that function which results from the additive combination of losses at (system) parameter vectors $\boldsymbol\theta$, or $L(\boldsymbol\theta)$ and the corresponding posterior probabilities, $\pi(\boldsymbol\theta|\mathbf{x})$, where $\mathbf{x}$ is the given data. In other words,

$\sum_{\theta_{i} \in \boldsymbol\theta} L(\boldsymbol\theta) \pi(\boldsymbol\theta|\mathbf{x})$

where, in principle, the $\theta_{i}$ are from the entirety of $\boldsymbol\theta$, but, since including $\theta_{i}$ which have loss contributions $L(\theta_{i}) \pi(_theta_{i}|\mathbf{x})$ other than local minima is doing worse than otherwise could be done, the above can be revised to:

$\sum_{\theta_{i} \in \boldsymbol\theta_{m}} L(\boldsymbol\theta) \pi(\boldsymbol\theta|\mathbf{x})$

where

$\boldsymbol\theta_{m} = \{\theta \in \boldsymbol\theta : \theta\,\text{is a local minimum}\}$

Now, sure, there might be some $\theta_{i} \in \boldsymbol\theta_{m}$ whose $L(\theta_{i}) \pi(\theta_{i}|\mathbf{x})$ are substantially above others and, so, can be neglected in choosing. But, then, per a Bayesian perspective, it’s important to considering the uncertainty in $L(\theta_{i}) \pi(\theta_{i}|\mathbf{x})$, either from model misspecification or because the loss function does not properly reflect actual losses. So, policy might want to seek neighborhoods of each $\theta_{i} \in \boldsymbol\theta_{m}$. Naturally, there are assumptions about continuity here: That is, one can imagine a theoretical $L(.)$ or $pi(.|\mathbf{x})$ which has discontinuities. Perhaps such things exist in climate systems. I do not know. I hope not.

Applying this frame to the climate problem, in addition to taking action because of Suitably Large Badness out there, in the presence of uncertainty — and quite contrary to luckwarmer arguments — uncertainty means choosing policies which steer outside of guard bands around problematic futures. In Jewish law, such guard bands are also known as boundary around the Law: In other words, the violation of a tenet is to be avoided. So keeping out of problematic cases or situations around the point of violation is a good idea.

126. from the Nature piece: “The Intergovernmental Panel on Climate Change (IPCC) introduced the idea of tipping points two decades ago. At that time, these ‘large-scale discontinuities’ in the climate system were considered likely only if global warming exceeded 5 °C above pre-industrial levels. Information summarized in the two most recent IPCC Special Reports (published in 2018 and in September this year)2,3 suggests that tipping points could be exceeded even between 1 and 2 °C of warming (see ‘Too close for comfort’).”

Let’s be clear and precise about the full implications of the fact that when the IPCC introduced the idea of tipping points 20 years ago, the changes were expected to happen with ~5C of warming. IPCC report 2018 says, maybe between 1 to 2C of warming. That’s a dramatic decrease in the time where we should expect to see significant feedbacks begin to alter our climate. This change in the amount of warming required to initiate significant feedbacks/tipping points means quite clearly that the impacts are happening faster than scientists anticipated.

Folks like Stern and Oreskes who write about the widespread phenomenon of impacts bigger and faster than expected get a lot of pushback, even from well-educated folks who should know better. This pushback even happens on this blog. See this post for that: https://andthentheresphysics.wordpress.com/2019/10/24/societal-tipping-points/

A question for ATTP: do you stand by your statement from that post? “I’m not convinced that they’re (Oreskes & Stern) correct that the effects of climate change are appearing faster than scientists anticipated.”

Cheers,

Mike

127. [Snip. -W]

Good heavens, Andy, if that’s what you took from my post, you really need [Etc. See, Willis? That’s bait. -W]

128. izen says:

@-Jeffn
“Are our universities focused more on producing the people who will design and build electric cars, or the people who will block the roads?”

Both are vastly out-numbered by the people on MBA courses.

129. verytallguy says:

Willard,

“Constructive criticism goes a long way with me.”

Willis could sure learn a lot.

130. AndyM says:

I wrote:

“… back in 2013 he was keeping an eye on snow extent because he was wondering if an Ice Age was on its way.”

“Good heavens, Andy, if that’s what you took from my post, you really need to [Snip. -W]”

And at the end of his 2013 article he wrote:

“Do I think that’s the case, that soot is all that is keeping the next ice age at bay? Y’know … I truly don’t have a clue whether that’s true or not. That’s one beauty of climate science, that there are so many mysteries.
I’m just saying, I’m keeping an eye on the snow extent ”

I don’t think I need write anything more.

131. Joshua says:

Willis –

Good heavens, this is what you wrote:

> So … would it not be truly ironic if pollution, in the form of soot and brown carbon, were all that has been holding off another ice age? And wouldn’t it be a cosmic joke if our efforts to clean up soot and brown carbon pollution were the straw that broke the back of the Holocene, and ushered in the new ice age?

I added the bold. I’d say a “last straw” analogy is analogous to a “tipping point.”

Seems reasonable to interpret that as you wondering about a tipping point (caused by cleaning up soot and black carbon) leading towards an ice age.

Good heavens.

132. “Both are vastly out-numbered by the people on MBA courses.”
Meh. Tesla is an awesome car, but navigating the challenges of organizing the building and selling of them are at least as important as the design.
When the history of all this is written, Elon Musk and the people who design, invent, and sell alternatives to fossil fuels will be in the chapters and XR will be in the footnotes to the appendices. That’s not punching hippies, it’s setting priorities. We all like to pretend it’s a uniquely capitalist concept, but the fact is that all economic systems look to allocate human brain talent to it’s highest priorities. It’s fair to start asking if we’re challenging our best and brightest to the right tasks. Merkel has challenged VW et al to switch from the ICE engine- more power to ’em. To make it happen in a global economy wedded to fossil fuels they will need all the brainpower they can get in the engineering, design, materials, and business offices.

133. ecoquant says:

@jeffnsails850,

When the history of all this is written, Elon Musk and the people who design, invent, and sell alternatives to fossil fuels will be in the chapters and XR will be in the footnotes to the appendices. That’s not punching hippies, it’s setting priorities.

I heartily agree.

134. It’s informative to observe the ferocity and absurdity with which the trolls attack a reasonable discussion of tipping points. I think the energy that these folks bring to confront a reasonable discussion of tipping points is a great example of how the right works to frame the debate and/or limit the discussion area to a range that automatically excludes certain topics and outcomes.

The relentless attack on the reasonable and rational discussion on the dangers of the climate emergency shows up in the way that the middle ground is constantly pulled to the right and influences reasonable and rational players to frame their concerns in the “middle ground” where folks like Rahmstorf, Oreskes, Stern et al are framed as radical in their presentation/position rather than as simply the most alarmed and alarming voices within a range of reasonable responses to our situation. I am convinced that the concerns of folks like Rahmstorf, Oreskes, Stern et al are quite reasonable, even though they are quite troubling to consider.

Don’t engage/feed the trolls too much. It doesn’t move them because their positions/motivations are primarily ideological. The RW trolls like to assert that ideology plays a strong part for those of us who are quite alarmed about global warming and I think that is true as long as the ideology is identified accurately as an ideology drive by a desire to leave a livable world for our grandchildren and their grandchildren. 7 generation ideology? I readily embrace that one.

Cheers,

Mike

135. izen says:

@-Jeffn
“We all like to pretend it’s a uniquely capitalist concept, but the fact is that all economic systems look to allocate human brain talent to it’s highest priorities. ”

I doubt any society has achieved such meritocratic purity.
If it is true at present then the best human brain talent is allocated to perpetuating the hereditary Oligarchy of rentiers that is the current economic system.

136. ecoquant says:

Well, I gotta say that the economic systems, whatever their faults, serve as a surrogate for the much harsher rule of natural selection.

137. David B. Benson says:
138. izen says:

@-[ecoquant]
“I gotta say that the economic systems, whatever their faults, serve as a surrogate for the much harsher rule of natural selection. ”

One key aspect of natural selection is the evolution of cooperation and mutual aid as a stable survival strategy.
Natural ecologys that require continual groooowth and increasing inequality that favours the few over the many are not likely to be stable.

139. ecoquant says:

One key aspect of natural selection is the evolution of cooperation and mutual aid as a stable survival strategy.

Surely that is not at all true for all organisms. Many virulent parasites kill off their hosts. Sure, there’s a tendency to moderate over time, depending upon the reproductive cycle of said parasite. But it doesn’t mean they’re nice to their hosts, even if they don’t kill them. What you cite is true of mammals and presumably hominids. But there are many exceptions.

And in the plant kingdom it is not true at all: Many species thrive by being positively toxic to normal plants about them.

140. Willard says:

> That’s not punching hippies, it’s setting priorities.

It’s actually the epitome of punching hippies, because were you dead serious about setting priorities straight and you sincerely believed that hippies don’t matter, then you’d stop mentioning them.

Either your scapegoat matters, or it does not. If it does, stop saying it does not matter. If it does not, stop mentioning it.

It’s not that complex.

Besides:

141. ecoquant says:

@Willard,

The trouble is the Carrying Torches and Pitchforks In the Streets image can strongly impede progress as well as help it.

142. Willard says:

@ecoquant,

How do you know?

I await your engineer-level formal derivation.

143. David B. Benson says:

Is East Antarctica closer to tipping than thought?
https://m.phys.org/news/2019-12-antarctic-ice-sheets-greater-previously.html

Clever geology, in my opinion.

144. Jan said:

“This is about decision making and statistics, signal detection theory, and all that, responding (finally) to the comment here. I deferred responding, since the response is a bit involved, but am ready now.”

This is interesting. Tipping points also exist in scientific analyses. See you over at the Azimuth Project 😉

145. izen says:

@-ecoquant
“And in the plant kingdom it is not true at all: Many species thrive by being positively toxic to normal plants about them.”

Plant ecosystems are highly dependent on mutual aid by plants of the same species, as in climbing plants, and by the symbiotic interaction with fungi that facilitate root growth and function.
It can be a conceptual myopia to only see competition between species or trophic levels as the defining feature of ecology.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4631906/

146. ecoquant says:

Alliaria petiolata, Brassicaceae, champion of invasion and survival.

147. izen says:

The issue of mutal aid in ecology is not OT with respect to ‘tipping points’.

Darwin’s “Grassy Bank” has a complex stable ecosystem dependent on the mutual interaction of a large diversity of plants, insects, earthworms, birds etc. big environmental changes can collapse such systems.
A current example would be how surface ocean warming, nitrate pollution, and overfishing can disrupt coastal reefs leading to the disappearance of the diverse species and the growth of a virtual mono-culture of algae mats with the risk of toxic red tides.

148. dikranmarsupial says:

Willis

“Do you think you can bring yourself to set your nastiness aside and stick to the science?”

also Willis

“Oh, piss off with your unwarranted claims of scientific superiority. ”

also Willis

“[#ButCensorship -W]”

Shame, I was hoping Willis would recognise the definition of a tipping point given in the IPCC WG1 reports, but perhaps that was an idea he couldn’t face.

149. Willard says:

Speaking of courageous ideas:

150. David B. Benson says:

Verloren

151. Joshua says:

How did the world survive before Internet tough guys arrived on the scene?

152. an_older_code says:

did “emergent thermostatic phenomena” ever get defined

153. Willard says:

> How did the world survive before Internet tough guys arrived on the scene?

***

> did “emergent thermostatic phenomena” ever get defined

That’s the first “emergent” I see in this thread.

154. ecoquant says:

@izen,

Sure, predator-prey mutualism and interdependency in trophic cascades. I wouldn’t say, though, that’s consciously cooperative.

155. izen says:

@-ecoquant
“I wouldn’t say, though, that’s consciously cooperative.”

Neither would I.
But then I often have serious doubts that much of human behaviour, cooperative or otherwise is actually consciously chosen.
Various competing factors just reach a tipping point, after which a post hoc rationalisation is invented.

156. an_older_code says:

I am a climate heretic. I say that the current climate paradigm, that forcing determines temperature, is incorrect. I hold that changes in forcing only marginally and briefly affect the temperature. Instead, I say that a host of emergent thermostatic phenomena act quickly to cool the planet when it is too warm, and to warm it when it is too cool.

sounds “sciencey” but what does it mean

157. an_older_code says:
December 3, 2019 at 4:23 pm

sounds “sciencey” but what does it mean

Thanks for asking. There’s a discussion of the basic ideas about emergent climate phenomena here, and a number of supportive posts here.

w.

158. Willard says:

Let me put forward one single challenge:

1) Define just WTF you are talking about.

Don’t come back before you do.

159. The Very Reverend Jebediah Hypotenuse says:

1) Define just WTF you are talking about.

Like Willis, I’m here to help…

“Emergent thermostatic phenomena” Def: it’s emergent, it’s thermostatic, and it’s phenomenal.

It’s also a sufficient condition for climate heresy.

And it Just Feels Right.

160. Ben McMillan says:

We have met the emergent thermostatic phenomenon and her name is Greta.

161. Everett F Sargent says:

The ‘so called’ “emergent thermostatic phenomena” can’t explain glacial-interglacial cycles. If the Earth had a governor (e. g. cruise control), it sure is a lousy one, that’s for sure.

A hypothetical lacking any form of conservation equations isn’t even a hypothetical, its only requirement is that it is a just so story biased towards an individual’s personal beliefs.

162. verytallguy says:

I dunno about everyone else, but I find Willis deeply tedious, but a better understanding of tipping points, particularly those for ecosystems, extremely interesting.

Perhaps the balance of posts being more to the latter than the former could improve discourse.

I fully acknowledge the self contradiction herein!

163. “It’s not that complex.
Besides:”

Heh. I suggest focusing on solutions instead of protestors, you say no then show solutions instead of protestors. Thanks!
If it works, those inventors will be in the history books. Set policy to encourage those where they work, have the humility to not demand them where they don’t, and encourage the kids to “go do more of that.”
It’s not that complex.

164. Joshua says:

VTG –

Among my favorite self-contradictions on the Internet

If everyone would just ignore the trolls who always write…

I never read the comments of the people who always write nonsense…

If people wouldn’t write such nonsense for me to read, they wouldn’t be wasting my time…

No good scientists attach meaning to a scientific consensus.

There are no reliable measurements of temperature trends, and there is no such thing as a global average temperature, and global warming has paused.

165. ecoquant says:

@jeffnsails850,

… and encourage the kids to “go do more of that.”

I think many will or at least might, at least the ones interested in STEM.

The discouraging voices I hear are often young adults (25+ y.o.) who want nothing to do with corporations or business or engineering, because they feel these institutions are in need of massive reformation, and cooperating with them is somehow selling out. I’ve tried to get some of them interested in, for instance, the Environmental Business Council of New England, and they want nothing to do with it.

166. Willard says:

> I suggest focusing on solutions instead of protestors

Stop. Punching. Hippies. JeffN.

Don’t mention them at all.

You root for engineers?

Good.

No more Greta this and XR that.

From now on, engineer stuff.

You’re on.

167. izen says:

@-eco
“The discouraging voices I hear are often young adults (25+ y.o.) who want nothing to do with corporations or business or engineering, because they feel these institutions are in need of massive reformation ”

The yoof may be right.
I am increasingly doubtful that any engineering solution is possible without radical change in the social systems, especially economic, within which such solutions are applied.

Perhaps the next financial crash will be a tipping point that triggers such change…

168. ecoquant says:

Turns out there’s a major article by James Temple in MIT’s Technology Review regarding tipping points which I just noticed at the MIT Climate Action site, specifically the page advertising tomorrow’s 3 hour mini-symposium.It’s called “Why we should be far more afraid of climate tipping points”.

169. ecoquant says:

Actually, it’s pretty disappointing … I was told it was a “major article”, but it really just points to the 2016 paper by . Kopp, Shwom, Wagner, and Yuan.

170. mrkenfabian says:

If mainstream politics faced up to this head on we wouldn’t get the protests – or not the kinds of protests that in effect, are asking those in positions of power, trust and responsibility to deploy their power in a trustworthy and responsible manner.

Green politics is a reaction to failures of mainstream politics. Those mainstream failures, on the other hand, are not a reaction to unreasonable demands of Green politics; they are a consequence of a broad desire of commerce and industry to avoid any climate responsibility and any burden of costs and inconvenience that comes with being held accountable for their actions.

Blaming environmentalists is convenient and opportunistic blameshifting. I think successful green politicking – demanding those responsible act responsibly – would actually render green politics irrelevant.

171. Willard says:

172. izen said: “I am increasingly doubtful that any engineering solution is possible without radical change in the social systems, especially economic, within which such solutions are applied.

Perhaps the next financial crash will be a tipping point that triggers such change…”

quite right. These opportunities do not exist within our normal socio-economic systems. The doors are open a crack when the normal socio-economic systems are shaken. This was the situation that Prez Obama walked into when he took the oath of office in 2009, but rather than creating a jobs program to produce a green energy grid, he chose to bail out the Wall Street banks.

I guess it’s a shame that we didn’t know about global warming in 2009. A smart guy like Obama would not have missed that opportunity if he had known about AGW.

So, yeah, maybe we get it off the starting line in the next financial crash. Hold that thought.

Mike

173. ecoquant says:

@mrkenfabian,

… [T]hey are a consequence of a broad desire of commerce and industry to avoid any climate responsibility and any burden of costs and inconvenience that comes with being held accountable for their actions.

While surely “commerce and industry” have some responsibility, if only to their owners if not society, this attitude that they are exclusively to blame is exactly the kind of line I find common in Sunrise, XR, and among many environmental progressives. It is wrong. A lot of the opposition to taking more aggressive actions on climate can be found among the population at town meetings and attending town committees. These are not people who are hoodwinked by “commerce and industry”, they are people who have come to believe they are better off without high taxes and don’t want government telling them what to by or what to do. They feel this even if you can point out to them it is in their own interests to pursue good options. On the taxes they are cheap. Despite a horrible mass transit system in Boston and commutes which keep people on highways for over an hour in traffic, including the health effects of breathing fumes, this public refuses to accept a higher gasoline tax to pay for better mass transit and dealing with highways. It’s coming to a head because gas receipts are diminishing, primarily because of more fuel efficient vehicles.

And people do not want means to decarbonize electricity to be built where they can be seen, and they want their big cars.

So, there’s a disconnect between the progressives and many people who vote and live.

It’s helpful to entice them through snazzy products like the Teslas and to make owning solar panels and batteries and heat pumps sexy, using the Steve Jobs approach to products. But that’s a long slow process. Still, it’s not appreciated by progressives who, basically, claim to just want to plant trees and put people to work.

174. ecoquant says:

I came across and read a pretty interesting paper by David Archer recently (“Near miss: the importance of the natural atmospheric CO2 concentration to human historical evolution”) which argues that if the pre-industrial concentration of CO2 had been a tenth of what it was at the time the industrial revolution occurred, humanity’s chances would have been far lower to escape:

Changing climate patterns would have been harder to discern, in a day without the global meteorological station network and communications of our world, and our longer historical record. Although Arrhenius had all the qualitative ingredients to explain a directed climate warming, a quantitative understanding was still decades out of reach. It is an interesting question to ponder, how much that might have mattered to impeding a social response to climate change. If real pain is mostly what it takes, Arrhenius would have had an explanation of how further pain could have been avoided. But to the extent that a thorough scientific understanding is also a requisite for making a decision to abandon fossil fuels, the outlook for humanity would have been considerably darker in this altered world than it turned out in actuality.

Professor Archer concludes we’re somewhat lucky we began where we did. The 288 ppm CO2 pre-industrial gave us a buffer.

175. mrkenfabian says:

Ecoquant – “A lot of the opposition to taking more aggressive actions on climate can be found among the population at town meetings and attending town committees. These are not people who are hoodwinked by “commerce and industry”

I disagree. Being largely employed by commerce and industry, the fears of job insecurity or income loss prompted by the views and positions owners and managers take flows through to individuals. More broadly, fears of rising prices flow through to their customers and communities at large. These kinds of indirect influence may exceed the influence from direct calls to opposition. Then there are major media outlets that, frankly, are aiding and abetting the desire of commerce and industry to remain unaccountable and have a outsized influence over the opinions of ordinary people.

We all tend to fall into one self interested category or another, but whilst all individuals have a share in the responsibility, corporations and institutions have much bigger – I suspect majority – shareholdings as well as more influence on policy and even on the framing of debate, through means that are not available to individuals. Alarmist economic fear has been perhaps the most potent obstructionist meme and theme of all; the desire of individuals to remain unaccountable and to avoid and excuse their own bit of responsibility at a small scale gets redirected, used and abused by commerce and industry to prompt popular support for preventing unaccountability at a large scale.

176. izen says:

@-kenfabian
“whilst all individuals have a share in the responsibility, corporations and institutions have much bigger – I suspect majority – shareholdings as well as more influence on policy and even on the framing of debate”

The prevailing narrative, or thesis, of our modern societies is that the individual in making choices shapes society. It is a dogma of capitalism that consumer choice selects the optimal means of supply of needs and wants.

The countervailing idea, antithesis, is that the socio-economic structure constrains those choices. For the vast majority there are not the technical or engineering means to obtain food, shelter, and safety except by ‘choosing’ the means available which constrained by the institutions, regulations and private enterprises that have the most power to shape and frame the social structure.

The synthesis should be that it is a two way street. That individual choice and structural constraints form a single interactive system from which emerges the policy and framing of the issues. But These available options are predominately based on energy from fossil fuels.

The problem with this apparent resolution of the dichotomy is that the power, or liberty of individuals to make choices, or frame and influence policy is largely dependent on the structure of how the ration tokens are distributed within the society. While it is not exclusively the case, wealth at the individual and corporate level is proportional to the amount of agency that is available to shape the social structure.

It is well established that wealth and the power and influence it confers has become increasing concentrated in a small elite, a ‘1%’ of individuals and businesses.
This video, and its graphs are now 7 years out of date. Things have only got more skewed since then.

177. mrkenfabian says:

Ecoquant, I don’t see your examples as evidence that commerce and industry and their lobbies have not been significant influencers – more like evidence of how long running and successful that influencing has been.

I think lots of the opposition to RE at local level is a consequence; the local opposition to specific projects arise from the divisive and tribal politics, which, especially early on as climate rose to prominence as an issue, persistently portrays climate actions as anti-business and climate activism as having an extremist/socialist ie anti-business agenda. Which some activism does. But when mainstream policy was non-existent and the only actions most people heard of were being proposed by environmental activists it made it easy to keep the spotlight on those kinds of extremists and their unreasonable demands – which shifted focus away from where responsibilities really lie. Commerce and industry had no desire to develop serious climate policies themselves – or support government actions likely to lead to regulations and pigovian taxation. They had a strong interest in preventing them and until RE got commercially competitive Business was collectively united in opposition to climate action.

When a region’s, state’s, nation’s business leaders oppose climate action, warning restrictions on their activities will result in economic downturns, bankruptcies and job losses then, irrespective of what the science says, politicians take what they want very seriously. Media that have businesses as their principle customers to promote their products are businesses themselves and have cause in common with commerce and industry in dodging corporate climate accountability; lots of ordinary citizens will find themselves agreeing that the problem is climate and renewable energy activists, not businesses making emissions.

I think that popular climate science denial and opposition is not genuinely grass roots; people are led to the opinions they hold and only rarely come to them purely on their own. The opponents of climate action have been led to their denial and opposition; associations of commerce and industry interests have had an outsized role in that.

178. ecoquant says:

@mrkenfabian,

… persistently portrays climate actions as anti-business and climate activism as having an extremist/socialist ie anti-business agenda.

Many of the towns opposing solar farms in western Massachusetts have a history of left-of-center activism, and certainly are not toadies for corporations. I know of one solar farm proposed in northwestern Rhode Island which was opposed by townspeople and the local chapter of the Sierra Club.

179. Joshua says:

eco –

I’m finally going to try to respond a bit to your December 2, 2019 at 5:21 pm comment. Hopefully you will see this.

> Given realistic distributions among possibilities for complicated systems, it’s entirely likely the posterior loss function is multimodal. This is not a consequence of Bayesian inference but of the complexity. Engineered systems are often designed so this kind of thing seldom happens, because they don’t want to deal with the multimodal optimization.

Ah, reality intervenes. Reminds me of a cartoon I once saw… two economists at a blackboard with a formula written out. They concur that it would work out just perfectly if humans could be eliminated from the model.

I could kind of parse the middle section of your comment but didn’t understand it at any level of detail…

> Applying this frame to the climate problem, in addition to taking action because of Suitably Large Badness out there, in the presence of uncertainty — and quite contrary to luckwarmer arguments — uncertainty means choosing policies which steer outside of guard bands around problematic futures.

Doesn’t that seem rather basic? Certainly does to me. Dipping into arguing from incredulity, I can see two basic reasons for not accepting that which seems obvious to me in this case. The first is that conditional probability is just hard. The 2nd is that an “agenda” enters into the analytical process. Of course, the first is often largely a function of the 2nd.

I suppose that the mantra of “no regret policies” (Judith likes to invoke them as a goal) is a very similar notion that “lukewarmers” often pay homage to. But in my experience, their commitment to such a policy frame is only surface deep. It’s rather similar to the level of commitment to nuclear energy I often see from “skeptics” and “lukewamers” – which extends only as far it is useful for punching hippies and hating on climate scientists and libz. At the point where nuclear would have to be paid for, support magically disappears.

> In Jewish law, such guard bands are also known as boundary around the Law: In other words, the violation of a tenet is to be avoided. So keeping out of problematic cases or situations around the point of violation is a good idea.

Interesting.

180. Steven Mosher says:

I will say this.

When Willis asked for a distinction between turning points and tipping points, it was clear he had his
thermostat hypothesis in mind.

basically he thinks the earth is self regulating. what turns up, must turn down.

181. David B. Benson says:

Stephan Mosher, that is the Lovelock and Margulis Gaia hypothesis. There are definite adherents.

182. Steven Mosher says:

hmm close, willis has his own particular spin … generalizing afternoon thunderstorms.

183. “hmm close, willis has his own particular spin … generalizing afternoon thunderstorms.”

Willis’ approach is applying ideas that he’s never learned from any science curriculum

184. Dave_Geologist says:

Gaia is a mass murderer several times over. First (if that’s how it started) of RNA-world by DNA-world. Then the Great Oxidation Event(s). Really only the final one around the time of the Ediacaran Snowball Earths. The others were more like ethnic cleansing, with successively smaller fragments of the ocean remaining as refugia for anaerobes. Then the Cambrian Explosion wiped out the Ediacaran faunas.

And of course geochemical and genetic evidence indicates that the early oceans were very hot, 60-80°C. Not much of a thermostat if you ask me: near-boiling to freezing. Aerobic life may have near-suicided several times in the Early Proterozoic Snowballs. The idea being that oxygen levels rose to levels which killed the Greenhouse and swung us into a Snowball under early-dim-Sun conditions. Only when the Sun got hot enough could that be avoided. That used to be associated with models that required methane as the GHG because CO2 levels seemed too low, but more recent assessment of Proterozoic CO2 levels as higher allows it without tortuous explanations for large amounts of methane.

185. Paul Pukite (@WHUT) says:
December 9, 2019 at 3:42 pm

“hmm close, Willis has his own particular spin … generalizing afternoon thunderstorms.”

Willis’ approach is applying ideas that he’s never learned from any science curriculum

Indeed, and that is the very definition of scientific progress, Paul. New ideas. New spins on old ideas. If everyone merely regurgitated the curriculum, progress would stop.
However, once again, here you are badmouthing what you seem to think are my ideas, with lots of handwaving, but not one single example of one single thing that I actually said that you believe is wrong. Not one. And in fact, that is all you’ve ever done regarding my work—whined and complained without being able to point to one wrong thing I’ve written.
And that is the very definition of the lack of scientific progress … indeed, such “contributions” as yours move the discussion backward.
w.
PS—For those unfamiliar with what Paul is whining about, here is an introduction to how I think the climate operates.

186. “At the point where nuclear would have to be paid for, support magically disappears.”

Really? It wasn’t cost that spurred opposition to nuclear in the ’70s and ’80s.
How did we pay for nuclear from 1970 to 1990 when it went from zero to 20% of American electricity production and zero to 80% in France?
If you compare French investment in nuclear to German investment in wind and solar, which worked out better from a cost and emissions perspective?

187. Everett F Sargent says:

” … here is an introduction to how I think the climate operates.”

Which lacks any forms of conservation laws and can’t even explain the current ice age glacial/interglacial cycling. Your own words don’t even meet the criteria for a hypothetical (e. g. it isn’t a conjecture, hypothesis or a theory).

Come up with a numerical model that satisfies the very basic conservation laws of mass, momentum and energy. Seriously, I don’t think anyone here is the least bit interested in words that basically states and then a miracle occurs. /:

Contrarians have no numerical models. What’s up with that?

188. verytallguy says:

Hi. Sorry to be so negative and all, but the topic is tipping points.

Willis’ personal theory of climate, fascinating as it doubtless is, doesn’t seem to be relevant.

Rather than drag this thread off topic, could I suggest those interested in such … groundbreaking work content at the link Willis so helpfully provided?

189. ecoquant says:

@jeffnsails850,

It wasn’t cost that spurred opposition to nuclear in the ’70s and ’80s.

Perhaps cost should have been the reason for opposition. Or, rather, the nuclear industry did itself in by pursuing a cost-plus business model rather than trying to make reactors repeatedly reliable commodity units. They opted for the defense contractor model of making each missile-carrying nuclear submarine unique.

This is why they have a negative learning curve compared to any other technology.

Environmentalists and NIMBYists aren’t who made nuclear power non-competitive: The industry did it to itself. And it didn’t help to align itself so tightly with the military nuclear weapons sector either, in terms of sharing fuels production and handling waste.

This is too bad: Yes, we could have used zero Carbon nuclear power, repeatable, reliable, and at a reasonable cost.

190. Everett F Sargent says:

vtg,

Some people here were late to the party, so to speak (e. g. responding to posts quite a bit upthread). Someone here has been rather vociferous from the get go, on the entire subject of tipping points. It would appear that their only argument for all this tipping point stuff was to talk about something, that, by its own self sealing processes, explicitly excludes tipping points. In other words,the Earth’s temperature is flatlined, has always been flatlined and will forever remain flatlined, no matter what nature or humanity does,

But yes to a tipping points only discussion.

191. ecoquant says:

Agreed @Everett F Sargent. Without this, a hypothesis is, in the words of physicist Peter Woit “not even wrong” (even if he borrowed it from Wolfgang Pauli, per Das ist nicht nur nicht richtig, es ist nicht einmal falsch!).

192. David B. Benson says:

ecoquant, the design engineers had to cope with the regulatory rachetting of the NRC; no design was good enough.

Rosatom is able to contract their VVER units for a stable price. Kepco even shows slight price improvements over time.

193. David B. Benson says:

https://en.m.wikipedia.org/wiki/Gaia_hypothesis
before commenting. It may not state what you think it does.

194. Steven Mosher says:

“Willis’ approach is applying ideas that he’s never learned from any science curriculum”

Thats not the problem. The issue is that the work is not grounded on a firm foundation
( which would have been learned in a science curriculum). Go back and read the spat

Bottomline: willis has no grad students.

195. ecoquant: “Perhaps cost should have been the reason for opposition. Or, rather, the nuclear industry did itself in by….” etc. Trimming only for brevity.
None of this explains France. A whole lot of money was spent in France on nuclear and in Germany on wind and solar. Which effort produced the most energy with the least emissions and the lowest cost?

196. ecoquant says:

France’s nuclear has a negative learning curve, too.

Check out page 10 of this.

197. David B. Benson says:

ecoquant, the EPR suffers a very bad case of safety rachetting. The units are almost unbuildable. EdF engineers state that they are going to redesign it.

In the meantime, SMRs, Small Modular Reactors, hold promise for inexpensive power.

198. ecoquant says:

@David B Benson,

Yes, SMRs should have been the way it was done from the beginning.

The thing of it is, though, that rolling out a new technology like SMRs is going to have its own curve of pain and costs, as well as qualification and learning how to do that. So, what, 20 years? 30 years before they are ready? Do they know how to rack and stack SMRs to get the equivalent of a 700 MW unit? Should be done that way, but mastering will take time.

By that time it’s entirely possible that wind+solar+storage+smart controls management will be unbeatable. You can put up a heck of a lot of wind turbines for the R&D on SMRs, and the designers and builders of SMRs are going to want their investments back. Plus you still need to maintain a mining source stream for fuels, a return destination for waste, and a conventional grid to distribute, and, until the redundant stack of SMRs is realized, something to jump in when one falls over.

Good idea, but kinda late.

199. David B. Benson says:

eqoquant, the Nuscale SMR is designed for 12pak units of 60 MW each. The first will be installed in Idaho Falls around 2027. There is no doubt that it will work.

The link I provided describes several other forthcoming designs.

200. ecoquant says:

I have heard of/read about Nuscale. I look forward to its success.

My only comment is it seems 60 MW is a bit large, but, then, I don’t know of the engineering challenges. I had hope they’d be small enough to be portable. My thought was that if they were, this would also address the nuclear wastes issue … You can roll away the spent one, and substitute a new module. The spent can be carried back to Wherever for reprovisioning.

BTW, I did have an NRC test engineer certification, once upon a time. I worked for a bit at the failing Westinghouse Nuclear Automation group.

201. David B. Benson says:

eqoquant, the Nuscale modules are truck transportable, requiring all of 2 lanes. Designed for refueling every 2 years, similar to the big boys.

Other designs are rollaway, most described in the provided link. Canada is particularly interested in such.

202. Willard says:

> Willis’ personal theory of climate, fascinating as it doubtless is, doesn’t seem to be relevant.

Longer threads can be more relaxed on topicality, but no more food fight, please.

203. Vidar Øierås says:

I question that any tipping points will be possible. In the far past, it has been much warmer than today. From a geological perspective it is said that the temperatures has reach 10+ C more than today, but the planets temperature did eventually recover into cooler climate. The temperature recovery might had happen over a very long period of time back then (?)

204. Dave_Geologist says:

In that case, perhaps I might be permitted to point out a better definition of scientific progress: The Relativity of Wrong, by Isaac Asimov. The Good Doctor doesn’t touch on Not Even Wrong, but a theory of a heat engine with no thermodynamics and no conservation laws would appear to fit that bill nicely. As would a theory of climate which can’t tell the difference between climate and weather.

205. Dave_Geologist says:

As to Gaia (back onto tipping points): I see no evidence that Gaia regulates well enough to prevent the AGW tipping points we worry about. As I pointed out above, She’s let far more catastrophic tipping points happen on Her watch. I cheekily capitalise Her because despite his denials, I’ve generally found that Lovelock drifts into teleological or quasi-religious thoughts when he gives a long description.

Gaian hypotheses suggest that organisms co-evolve with their environment: that is, they “influence their abiotic environment, and that environment in turn influences the biota by Darwinian process”.

Few would disagree with that.

Less accepted versions of the hypothesis claim that changes in the biosphere are brought about through the coordination of living organisms and maintain those conditions through homeostasis.

Many would disagree with that. Especially geologists (notwithstanding the GSL awarding him a Medal – I presume they had the first quote in mind). A homeostat that can’t stop Ice Ages or indeed Snowballs, didn’t stop the PETM, didn’t stop volcanic injection of CO2 and aerosols causing catastrophic warming (most extinctions) or catastrophic cooling followed by warming (the Ordovician, and perhaps the Permian), didn’t stop ocean anoxia, and has consistently failed to stop environmentally induced mass extinctions, ain’t gonna rescue us from our folly.

The Great Dying came close to wiping out all macroscopic life, and left a planet too hot for fish or reptiles (and of course mammals) to survive in the Tropics. The Ediacarans flourished for 100 m.y. then were wiped out. Unless you think the subsequent shelly faunas were somehow more “deserving”, or being more “advanced” were favoured by Gaia, which sounds a tad teleological for my taste, She’s a rather uncaring Mother.

206. Vidar,

I question that any tipping points will be possible. In the far past, it has been much warmer than today.

That isn’t an argument against tipping points. In this context, a tipping point means something that is triggered and is essentially irreversible on relevant timescales. For example, we could get warm enough that the Greenland ice sheet starts melting and will completely melt even if we reversed some of the warming that triggered this. This doesn’t mean that the Greenland ice sheet will never reform, it just means that it’s not going to reform on any timescale that we care about.

207. ecoquant: “The thing of it is, though, that rolling out a new technology like SMRs is going to have its own curve of pain and costs, as well as qualification and learning how to do that. So, what, 20 years? 30 years before they are ready? ….By that time it’s entirely possible that wind+solar+storage+smart controls management will be unbeatable.”

We’ve been hearing that wind and solar (plus the long list of backups and grid improvements and meter replacements) would be “unbeatable” for 50 years. And they aren’t yet and show no signs of being so anytime soon. Meanwhile alternatives beat them. Either you believe in urgency, or not.

208. Everett F Sargent says:

jeffnsails850 sez,

“Either you believe in urgency, or not.”

Nice! Strawman that is.

209. David B. Benson says:

Too warm in Siberia for bears to hibernate.

210. Willard says:

> Meanwhile alternatives beat them.

I see what you did here, JeffN.

211. ecoquant says:

@jeffnsails850,

We’ve been hearing that wind and solar (plus the long list of backups and grid improvements and meter replacements) would be “unbeatable” for 50 years. And they aren’t yet and show no signs of being so anytime soon.

Well, I haven’t heard that, whether from the U.S. EIA or the corresponding UN agency, , the IEA, or from our local ISO, ISO-NE. All three of them underestimated the growth of PV, in particular. And if you paid any attention to the Lazard unsubsidized LCoE I posted, you can see the dramatic drop in per kWh costs for particularly utility-based PV and wind. Yes, residential PV is slower, costlier, but there are plenty of reasons why that’s the case. Some of these are regulatory distortions which, yes, sometimes help adoption but also tend to put price floors under things. There are also regulatory obstacles, at least in the USA and especially in places like Massachusetts or Florida, which impede private adoption of PV and wind, something which Germany understand, during Engergiewende, they needed to prohibit.

In any case, if an exponential is fit to the price curve for unsubsidized PV LCoE you get an $R^{2}$ for the fit which is 0.95, meaning it’s really good. So, despite it being an extrapolation, I am comfortable forecasting the price per MWh of PV at utility scale in early 2030s as being under US$1, setting aside, perhaps, cost of money for capital installations. That’ll be hard to beat, even if it were intermittent. Check out the LCoE for storage, too. I also think people are excessively focused upon LiON batteries for storage: There are competing technologies coming along, including creative ones. Finally, what many people appear to overlook, even some PV and wind proponents, is the degree to which computing and controls can make a big difference with these and storage, not only because it’s all electricity, but because, in principle, the lags between commanding a change and realization are much shorter for these, especially for PV and storage, than trying to electronically turn the throttle down on a fossil fuel or nuclear plant. I think there are many opportunities for exploiting Sankey and Carnot efficiencies here. I also think that all that will happen if regulatory opposition gets severe is that there will be islanding of sections of the present grid, with these islands being replaced by mostly self-contained microgrids which will reserve the capability of occasionally buying electricity — perhaps at inflated prices — from the existing grids, or neighboring self-containeds. This would be unfortunate, since it would mean the benefits of such electricity and capability would be restricted to the relatively wealthy, whereas if the vested interests were more enlightened, it could be everyone. But, then, they are vested interests. This is not just some pipe dream, but has been written about and talked about for many years in the IEEE Power and Energy section. 212. David B. Benson says: ecoquant, the exponential for Moore’s Law, so-called even for switching rate, came to a sudden halt. The same applies to other semiconductor applications such as solar PV. I doubt 2 more halvings are possible. Still, that makes for impressed inexpensive electricity! Similarly for the improvement in batteries although I don’t know enough to offer an opinion. Perhaps flow batteries can be. 213. ecoquant says: @David B Benson, Moore’s Law is the paradigm here, but is not the cause of PV cost decreases. It’s Swanson’s Law, and it is based upon a lot beyond fabrication cost of modules. The recent step drop in anticipated costs is because of bifacial units. Also, as deployment has moved out, racking and placement technology has dropped the time for installation and so the labor costs. Eventually, we’ll see PV arrays that will be upgraded, as efficiencies improve. The bleeding edge of PV efficiencies is provided by the arrays used for spacecraft, obviously at much higher prices. But reducing those prices is where the engineering can improve, and spacecraft efficiencies are substantially better than commercial. The inherent limitations of the technology are reviewed here, but these do not include improvements in inverters and the like. 214. Francis Logan says: Re nuclear v solar: In 2006, California passed SB-1, the Million Solar Roofs program. In reporting I saw today, California met that goal last July and, due to improvements in technology, generated far more power than first expected. Total roof solar power generation is 8,730 megawatts, or the equivalent of four Diablo Canyon nuclear power plants. See here. 8 gigawatts in 12 years from a standing start. Commercial nuclear power is about 80 years old and still can’t get plants built on time and on budget. 215. David B. Benson says: ecoquant, your second link leads to a summary which agrees with my statement: another factor of 2 to 3. That implies less than$10/MWh, which is very impressive.

216. David B. Benson says:

Francis Logan, both Rosatom and Kepco build their respective nuclear power plants on time and in budget. I suppose that this is true of the Chinese vendors as well.

217. Ben McMillan says:

The Barakah plant is Kepco isn’t it? If it starts next year it will only be 3 years late, which is certainly better than Flammanville. Not clear how close to original budget it is.

218. David B. Benson says:

Ben McMillan — Kepco built Barakah on time and in budget. It sits idle due to UAE incompetence and possibly corruption. The highly successful manager of the Columbia Generating Station, the best run nuclear power plant in the USA, has taken up the lead management position of a UAE-Kepco organization to run Barakah. I wish him luck in his relations with the powers-that-be in the UAE7.

219. You can get to 20-30% of wind and solar before you essentially hit a wall and realize the grid costs and massive expenditure on backup generation is both financially and technically unsustainable. Real world experience has already doubled electricity prices for consumers and it’s a whole different ballgame once you attempt to fully replace baseload power with intermittent sources. Germany is there, that’s why they’re expanding gas pipeline capacity, approving Volkswagen’s switch to gas from coal, and issuing press releases about electric cars.
Then we have more real-world experience. We have press releases saying wind and solar are effective, the cheapest, and the fastest to scale and yet developing nations, those most sensitive to the need to scale up fast inexpensively, aren’t choosing it and the UN says they must be allowed to instead use coal and gas out of a sense of climate justice. These two claims cannot exist simultaneously.
Cue Joshua with his magic word “externalities” that makes “cost” irrelevant in ways so obvious that it’s amazing not a single country or the UN agrees with him.
By the by, anyone want to take a stab at why we’d need “total economic transformation” if wind/solar are cheap, scalable and can effectively power a modern western nation? Capitalism is brutal on cost cutting.

220. ecoquant says:

Actually, NREL, Haas, and others say 70%-80%, as long as FERC and company are doing the right thing.

221. Steven Mosher says:
222. Steven Mosher says:
223. Steven Mosher says:

“Total roof solar power generation is 8,730 megawatts, or the equivalent of four Diablo Canyon nuclear power plants. See here.”

224. Ben McMillan says:

And isn’t the Shin Hanul plant, which started construction 2012 also Kepco? Isn’t that also a couple of years late? Being technically complete is not much use if they aren’t connected to the grid and generating power.

225. David B. Benson says:

Ben McMillan, Shin Hanul units are Kepco. As far as I know everything is going according to plan.

As for the UAE, the minister in charge does not appear to be in any hurry to even complete the necessary training, much less load fuel. Don’t ask me to explain why.

226. Ben McMillan says:

Well, as far as I can tell Shin Hanul 1 was meant to be generating power 2018 (maybe originally 2017?), and still isn’t connected to the grid.

227. JCH says:

Tim Palmer discusses issues in recent paper he did with Bjorn Stevens, tipping points, etc.

228. Ben McMillan says:

I think opponents of wind/solar have always claimed that you hit some kind of a barrier at X% of generation.15 years ago the hard barrier was meant to be 20%; maybe now the talking point is 30%. It had better adjust upwards again soon.

Seems that a lot of EU countries are at around 30% wind/solar now and climbing without anything dramatic happening. Backup largely consists of running existing gas and hydro plant. There hasn’t actually been much investment in transmission recently.

This has led to a dramatically cleaner grid in a lot of places. 30% wind and solar might not seem that much, but EU has ~20% each of hydro+nukes, so that starts adding up.

229. David B. Benson says:

Ben McMillan — Required safety upgrades beyond original specs:
https://asian-power.com/power-utility/news/korea-delays-completion-shin-hanul-1-2-nuclear-reactors

230. Ben McMillan says:

DBB: OK, it might not be Kepco’s fault, but that’s a bit different to most people’s idea of on time and in budget.

Also, there is a pattern here. Things take so long to complete that the regulatory environment changes before the end of the project. Some major external event takes place (earthquakes/fake reactor parts in the case of south Korea). The result is that the project is more expensive to complete because delays increase financing costs and extra safety measures increase costs, and the next project has a bigger risk premium added to it.

231. Chubbs says:

JCH – Thanks. Funny how the recent Palmer and Steven’s paper is misrepresented. Here’s my take – We need better models because we have ignored models for decades. Now regional impacts and tipping points are ramping in an unpredictable manner and we need info on which holes to plug first.

232. ecoquant says:

Also … What’s the operation time needed to offset emissions for manufacturing a nuclear station’s components and especially the concrete/cement/ metal /fuels nvolved, as well as emissions from heavy machinery to build,?

233. Ben McMillan says:

https://www.carbonbrief.org/solar-wind-nuclear-amazingly-low-carbon-footprints

Pretty quick energy payback for any of the usual low-carbon powerplants. Embodied energy is 5% of generated energy. So of order 1 year. Answer changes a bit if the electricity used to build the plant is already quite low-emissions.

234. JCH says:

Chubbs – yes, it’s pretty amazing. He calls the climate models of the 20th and 21st century remarkably accurate, and says warming by 2100 will be 3 to 4 ℃. He speculates areas of the earth’s surface may become too hot for human beings to live.

Obviously they could live there with AC and even work outside if they wear space suits, so no concern there. Like coral reefs, mankind will adapt.

But this, I think, is essentially as much a broadside against Professor Judith Curry, Etc. as anybody else:

…While we are certainly not claiming that model inadequacies cast doubt on these well-settled issues, we are claiming that, by deemphasizing what our models fail to do, we inadvertently contribute to complacency with the state of modeling. This leaves the scientific consensus on climate change vulnerable to specious arguments that prey on obvious model deficiencies; gives rise to the impression that defending the fidelity of our most comprehensive models is akin to defending the fidelity of the science; and most importantly, fails to communicate the need and importance of doing better.

235. ecoquant says:

@Ben McMillan,

Encouraging, although the cited paper only expressed indirect emissions as a fraction of lifetime energy production and, even consulting the supplements, there is no way to know what lifetimes and productions they are assuming for each of the sources, nor what the raw emissions are.

Moreover, this emissions intensity-based approach could be misleading. I’m not saying it’s actually this high, but suppose replacing fossil fuel electricity generation now and all needed for decarbonizing transportation and manufacturing entirely with nuclear emitted 200 GtCO2 for just construction, about 5x a single year’s global emissions now. While the total generation of MWh might be enormous and, so, the density low, 200 GtCO2 is nuthin’ to sneeze at.

Granted, though, wind’s indirect emissions are really low, less than 1/3 of nuclear, and the median of solar PV is about 1/2 of nuclear, although it has quite a range of uncertainty.

I am skeptical about the comparison between wind and solar … You would think wind would have more because of concrete foundations, etc. Is manufacturing wafers that much more emitting? Can’t tell from the paper for the same reasons as indicated above. They also don’t specify the scale of PV or wind buildout.

Finally, the hero of nuclear electricity, France, is apparently going on a non-nuclear renewables splurge. Huh. Isn’t that somethin’.

236. ecoquant says:

@JCH,

Obviously they could live there with AC and even work outside if they wear space suits, so no concern there. Like coral reefs, mankind will adapt.

The adaptation of coral reefs is far from assured. Success in a warm future doesn’t mean success in an acidified future. Moreover, the robust corals are relatively rare, and their present havens could be annihilated by human misbehavior, nothing malicious, just the usual carelessness. Indeed, the havens are so rare, there’s currently an emergency campaign to protect them.

The per unit cost of labor outdoors wearing “space suits” is undoubtedly much higher than simply working outside. This attitude is clearly that of a superior, if myopic, OECD perspective. Consider what you are saying: You are proposing the transformation of a piece of the planet into a condition comparable to an airless world, and you are okay with that. I’d say your priorities are plainly messed up.

237. Ben McMillan says:

Well, PV is about 200W/m^2 peak, so one wind turbine (5MW) worth of PV is 25,000 square meters plus support structure and foundations. Wind has about double the capacity factor too.

Once something is an order of magnitude better than existing I tend to think that is sufficient. Yes, things like PV/wind turbines have embodied energy/carbon. No, it doesn’t matter very much.

238. JCH says:

ecoquant – I’m making fun of a certain scientist who suggested air conditioning was a viable solution to stop people in certain countries from dying in heat waves. I added the space suits, but I agree it was already absurd enough.

239. JCH says:

Constraining equilibrium climate sensitivity through simulation of Eocene extreme warmth

Abstract

Equilibrium climate sensitivity (ECS), defined as the global equilibrium surface temperature increase to the radiative forcing caused by a doubling of atmospheric CO2 concentration, is the single number that describes the severity of long-term climate change. ECS is poorly constrained with a range of 2.1–4.7 ℃ in the Coupled Model Intercomparison Project phase 5 (CMIP5) models. The upper bound of ECS has been raised to more than 5 ℃ in recent CMIP6 models. Past hothouse climates, such as the early Eocene (~56–48 Ma), with elevated atmospheric CO2 concentrations and extreme warmth, provide unique constraints on ECS in climate models. Here we conduct early Eocene simulations using three generations of the Community Atmosphere Model (CAM4, 5 and 6) within the framework of Community Earth System Model (CESM). With CO2 levels consistent with latest proxy reconstructions, CESM-CAM5 best reproduces the extreme warm conditions of the early Eocene in proxy estimates. In simulations of the preindustrial, ECSs in CAM4, 5 and 6 are 3.2, 4.2 and 5.3 ℃, respectively. ECS increases with warming in Eocene simulations in all three models, albeit at different rates. The increases in ECS with warming and the differences among CAM4, 5 and 6 are attributable primarily to the simulation of cloud processes. Mechanisms for differences in the simulation of clouds and their influence on ECS will be discussed in detail. The good match of CESM-CAM5 and early Eocene proxy temperatures supports the physical processes represented in the model, and suggests a present-day ECS of ~4 ℃ that will potentially increase with future warming.

240. JCH says:

Got this in the wrong order. This article sent me looking for the large study mentioned, and I found the above, which is being presented AGU10.

New climate models predict a warming surge

In assessing how fast climate may change, the next IPCC report probably won’t lean as heavily on models as past reports did, says Thorsten Mauritsen, a climate scientist at Stockholm University and an IPCC author. It will look to other evidence as well, in particular a large study in preparation that will use ancient climates and observations of recent climate change to constrain sensitivity. IPCC is also not likely to give projections from all the models equal weight, Fyfe adds, instead weighing results by each model’s credibility.

241. Dave_Geologist says:

Grrrrrr.

Pedantic point. It’s only equilibrium sensitivity in the model world, not in the real world. Slow Earth System feedbacks will continue (OK, we’ll all be dead by then) and have their own tipping points. For example we have about a thousand years to draw down atmospheric CO2, not just stabilise it, otherwise we’ve cancelled the next Ice Age because albedo will have fallen below a bifurcation point. Of course you might argue that that’s a good thing – a Goldilocks outcome. IIRC there will still be one in 100ky or so, when the Milankovitch cycle is less albedo-dependent and there has been more natural drawdown (although CO2 remains the main control knob, there are subtle variations in the relative impact of albedo and CO2, depending on which cycle we’re in).

And as an ex-editor, I hate “Mechanisms for differences in the simulation of clouds and their influence on ECS will be discussed in detail”. Don’t be coy – especially in the modern world of abstracts online but articles paywalled. I don’t want to read twenty papers to find the topic I’m looking for, and you don’t want to miss out on readers by not flagging what’s new and important about your results. OK, maybe it’s all right in a conference, as a teaser and where people can ask you in the bar or over coffee what the punchline is.

242. Chubbs says:

An interesting paleo paper linking Siberian permafrost to year-around sea ice. New to me: continuous year-around sea ice has only existed in the past 400,000 years, providing an important roughly 2C tipping point. Behind a paywall, but the figures are available. Figure 3 presents the evidence clearly.

243. Dave_Geologist says:

Another tipping point paper. It’s almost as if we’re getting close enough to having one explode in our face that people consider it an important area of research 😉 .

Using microfossil temperature reconstructions, we show that the current interglacial is unusually moderate and that all 4 previous interglacials were warmer than present near Greenland. Both magnitude and duration of past warmth were important influences on the ice sheet. Notably, the critical temperature threshold for past GIS decay will likely be surpassed this century. The duration for which this threshold is exceeded will determine Greenland’s fate. …

Models suggest a possible temperature threshold between 0.8 and 3.2 °C, beyond which GIS decline becomes irreversible. The duration of warmth above a given threshold is also a critical determinant for GIS survival, underlining the role of ocean warming, as its inertia prolongs warmth and triggers longer-term feedbacks. … Complete deglaciation of the southern GIS in Marine Isotope Stage 11c (MIS 11c; 394.7 to 424.2 ka) occurred under climates only slightly warmer than present [Note: not than pre-industrial] (∼0.5 ± 1.6 °C), placing the temperature threshold for major GIS retreat in the lower end of model estimates and within projections for this century. …

A low GIS threshold increases the plausibility that one of the most economically impactful (25) long-term consequences of warming could be passed well below the 2 °C threshold and may already be unavoidable if even modestly warmer conditions were to persist long enough (26).

244. DG says on tipping points: “It’s almost as if we’re getting close enough to having one explode in our face that people consider it an important area of research”

I think the most logical explanation for our collective failure to do research and employ the precautionary principle wrt to tipping points/abrupt change, etc. is that the holders of wealth and power have largely accumulated their wealth and power from fossil fuel activities and these folks want to wring every last cent or profit out of the assets they control, no matter how toxic the assets and processes might be.

There is talk about disruption of economic systems, but I think that is clearly a tool/story pushed by the holders of power and wealth based on the current system, there is plenty of reason to believe that retooling our power system is full of economic opportunities and activities, but this changeover is essentially a disruption where power and wealth may be in play and move to new loci.

It’s hard to watch this disruption of disruption play out, but to paraphrase Frederick Douglass: power concedes nothing without a demand and the demand is usually met or unmet through conflict. I think a slavery-based economy is the correct comparison to our current fossil fuel-based economy.

245. Dave_Geologist says:

The research is being done mike. It’s just not being acted on. In part because the precautionary principle is being applied to expenditure and lifestyle changes rather than to climate impacts.

It’s bottom-up as well as top-down. People are very bad at taking short-term action to forestall long-term problems. Look at the number of people who still smoke, and the growing obesity crisis.

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