The impact of climate change

As a physicist I think I understand the impact of climate change from a physics perspective. If we continue adding CO2 to the atmosphere, we will continue – on average to warm. We also have projections for the range of warming based on different possible future emissions pathways. We also expect polar amplification; the Arctic will warm faster than regions at lower latitude. This will change the latitudinal temperature gradient and should affect global weather patterns. We expect the hydrological cycle to intensify; regions that already have lots of rain will probably get more, and regions that are dry, will get drier. This will likely influence flooding and droughts.

Adding energy to our climate system is also expected to increase the intensity and frequency of some extreme weather events. These are complex processes, so we may not be able to predict accurately what will happen, but we already have some evidence to suggest a relationship between the intensity of Tropical Cyclones, and sea surface temperature.

However, what I don’t know much about is how – more specifically – these changes will influence us. How will a warmer world influence our (humans) ability continue living in a manner similar to, or better than, we are today? So, a few days ago, I was emailed an infographic that tries to explain what might happen. The source is here, but I thought I would also post it below. I don’t know the credibility of the information on the graphic, but I thought some of my more well-informed commenters might know more about this than me, and may be able to clarify whether or not what this infographic presents is a reasonable representation of our current understanding of the possible impacts.

Source : Inforgraphicworld

Source : Inforgraphicworld

Advertisements
This entry was posted in Climate change, Global warming, Science and tagged , , , , , . Bookmark the permalink.

99 Responses to The impact of climate change

  1. I think you’re right to raise questions about this graphic. It seems unbalanced and incomplete. It doesn’t mention directly the impact of drought and flooding on agriculture, which will be probably the most significant effect on our existence. Rising oil prices are mentioned, yet they’re only very indirectly connected to climate change. The other thing completely missing—which, for a large part of the world, will have the biggest impact—is the effect of ocean acidification on fish stocks. Finally, a major multiplier, making all the other problems worse, will be to migration of people away from areas of the globe which can no longer support their current, never mind future, populations.

    I guess it’s difficult, because every country will be impacted in such different ways.

  2. John,
    I hadn’t actually had a good think about it before posting it, but you’re right, not mentioning ocean acidification does seem a little odd. The one thing I did wonder is why the very last thing is that poison ivy and dandelions will grow bigger and stronger. Doesn’t seem like a particularly strong way to end such an infographic.

  3. I think this is a more effective approach to explaining the potential impacts. More ‘sciency’, less simplistic: http://www.carbonbrief.org/media/322456/wri-square-infog.png

  4. Yes, I think the reason I got sent the one I posted here was because I’d retweeted that one from carbonbrief.

  5. Perse says:

    Ah! Oh no! Those outcomes sound terrible and I’m so scared! I’ll just pretend this doesn’t exist because I don’t know what to do about it…

    I don’t really think that. Just imagining what uninformed people will say when they see that. That article is nothing more than a bright-colored advertisement to scare people, only made interesting to us because it seems to agree with our position on the climate change “debate.” It lists a lot of scary things but doesn’t give any evidence. It seems to be a “counter-protest” of sorts. In the debate of climate science, there is the voice of reason, the frightened “skeptics” who run and hide, and the activists, counter-protesters in a sense, who try to counter senselessness with their own senselessness in an effort to speak the language. It doesn’t give a convincing argument, it only scares people so they’re more likely to hide from the truth.

  6. Perse,

    It lists a lot of scary things but doesn’t give any evidence.

    Yes, that’s a little like my position. I’d like to know more about how it might impact us and why, but – as you say – this infographic presents information, but doesn’t really explain why or how convinced we are of the different impacts. The graphic that John included in his comment above also shows the impacts of the different emission pathways, which I do think is quite important. What happens is going to depend on what we choose to do. We, in a sense, have control over our future.

  7. Perse says:

    Reblogged this on Perse Show and commented:
    I understand the idea of being scared of something and hiding from it–I’m probably guilty of that myself sometimes–but please don’t post scary, bright signs on the Internet! There is no proof or evidence here! It may sound like it “believes” in climate change, but it’s only going to drive frightened people further into hiding from the truth, and that will not help our society if climate science is indeed a danger!

  8. But the convincing argument is also scary, Perse. That’s the conundrum. Does one tell it like it is and scare people, or play it down so they don’t bother to respond? Action on climate change is surely the ultimate ‘distress purchase’.

  9. John,

    Does one tell it like it is and scare people, or play it down so they don’t bother to respond?

    I think that’s why I quite like the one you linked to, as it included how the different pathways might influence us. That tells is that we have a choice as to what kind of risks we might face (or, rather, we can make choices that reduce the risk of the most severe impacts).

  10. Perse says:

    I see what you mean. We walk a thin line here as science people, one I’m only beginning to understand. It just bothers me when people post random scares. Is that what this society has come to? We can’t talk and be honest, we have to scare each other into action?

  11. Perse,

    We can’t talk and be honest, we have to scare each other into action?

    There’s also the other side of the coin where anyone who says anything that might be regarded as remotely concerning is regarded as being too alarmist. As you say, we do walk a thin line and people have different ideas of what works and what should be presented.

  12. Presumable the 11.5 degrees threatened by 2100 CE is in some quaint colonial unit rather than an SI unit.

  13. richard,
    Yes, I was assuming the same. I notice that some of the colonies do still present it in this quaint, old units 🙂

  14. Perse says:

    I envision a world where everyone talks and tries to get along. It doesn’t always work, but they still try. I know that vision will never happen to the world we live in now, but I can still provide the best example possible. I just try to speak my mind and see what works.

    Regarded as being too alarmist? That particular issue drives me nuts, because you’re totally right, that’s how people think. Random scares are “alarmist,” not honest conversation! And heck, if I have to be “alarmist” to tell people the climate is indeed changing, I’ll be proud of it because it’s the *truth* dictated by strong *evidence* that the climate is changing! Even if I won’t approve of the use of the term “alarmist.”

  15. Perse,
    Well, I hope you can maintain your optimism.

  16. “We can’t talk and be honest, we have to scare each other into action?”

    If only the subject was one that we could all sit down and talk about, honestly. The problem is the press, most of who want to print crap and the remainder who believe in ‘balance’, even when it’s a false balance. And then the press are fed by a big denial industry whose stock-in-trade is sowing doubt. Then there’s the small contingent of influential people who have taken a look at the facts and rejected them because the science doesn’t fit in with their world view. This vocal group shout loudly while knowing nothing about the subject. Lastly there is the great majority, who are concerned but think that, if there is a serious problem, ‘They’ will take action. My wife falls into the last category. She knows all the science (mainly because I can’t stop mentioning it on every occasion) yet whose response is, “well, what can we do?”

    So I guess the bottom line is how do we start the ball rolling? Personally, I’ve set as good an example as I can: insulating my home until it’s EPC band ‘A’, installing solar pv and thermal, a heat pump; planting 100 acres of trees, harvesting water, stopping all travel outside the UK, not replacing my car (which will do 70 mpg). So where next? How do we get people to listen and start making a noise the politicians will respond to? …For the politicians will only get serious if they know it’s a vote winner. Catch 22.

  17. Vinny Burgoo says:

    Thanks for that. A keeper. I particularly like ‘Day-to-day transportation will be more difficult and expensive’, a nice example of confusing climate change impacts with mitigation impacts.

    Here’s my heretofore favourite climate change infographic:

    https://twitter.com/VinnyBurgoo/status/501082778344390656

    I have no idea what it was supposed to say. It’s from a 2011 presentation by Hugh Montgomery, a sort of climate change Sportacus who specializes in selling climate change to children.

  18. Vinny,
    I saw you’d just RT’d that. I didn’t get it either.

  19. Vinny Burgoo says:

    Wotts, I didn’t RT it. I uploaded the pic to Twitter because it’s easier than using Dropbox etc. these days.

    So the caption was mine, not Montgomery’s. He didn’t apply one to that pic but the whole presentation was called ‘Why Should Young People Create a Greener Britain’.

    Just to clear things up. Not trying to divert the thread or anything. (But he’s worth a google.)

  20. I can’t really bear to rip this thing to shreds, its so fragile. But I will. Just to rescue one point first:

    > why the very last thing is that poison ivy

    I think that’s supposed to be the first thing. Its a thermometer; you read it from the bottom. I think.

    Food: I don’t believe this. Food will continue to become cheaper *overall*. The effects of GW are likely to be a factor causing increase, but that factor is (likely to be) overwhelmed by all the other obvious things, most notably making more efficient use of land in less developed countries.

    Bees: at least in the UK, what’s causing bee declines is varroa, not climate (I speak as a beekeeper, BTW, lest any doubt my expertise).

    Top pic shows people sweating at 7 am cos its getting hotter. But this is unthinking. Go to anywhere hot (south of France; we went to Greece this summer) and you can find cool buildings because they know how to design them. So, adaption. Note that I’m *not* proposing that this solves all problems but I do think this graphic is too naive to be useful.

  21. anoilman says:

    Perse: I tend to agree with your assessment of that. Although, I don’t think Joe Public would understand if you offered him detailed explanations and statistics. This is what the denial community is exploiting against Joe Public.

    What offends me the most though is that the Denial Community has worked so hard and so successfully at confusing this, that the cure is likely far far far more painful. Cutting fossil fuels was easier in the 1990s when consumption was lower. Now our consumption is higher, and the fuels are dirtier (fracking).

    The time to happily calmly start sorting this out was then, and every year we put it off it hurts more and more.

    “The best time to plant a tree was 20 years ago. The second best time is now.”
    –Chinese Proverb

  22. William,
    Yes, you’re right, it is meant to be read from the bottom up. Of course, if it’s on a webpage, the chance of someone realising that before having started at the top, is probably slim.

    Bees: at least in the UK, what’s causing bee declines is varroa, not climate (I speak as a beekeeper, BTW, lest any doubt my expertise).

    Yes, the bee issue seems entirely separate to the climate change issue.

    Food: I don’t believe this. Food will continue to become cheaper *overall*. The effects of GW are likely to be a factor causing increase, but that factor is (likely to be) overwhelmed by all the other obvious things, most notably making more efficient use of land in less developed countries.

    This seems reasonable for modest warming, but do we have any real idea of the possible impact of 5 degrees of warming in the next century if we follow a high-emission pathway?

    Top pic shows people sweating at 7 am cos its getting hotter. But this is unthinking. Go to anywhere hot (south of France; we went to Greece this summer) and you can find cool buildings because they know how to design them. So, adaption. Note that I’m *not* proposing that this solves all problems but I do think this graphic is too naive to be useful.

    Indeed. Presumably the real issue, if we do follow a high-emission pathway and have a lot of warming by 2100, is the extremes, rather than the typicals.

  23. anoilman says:

    William Connolley: Yep… Food production may decline, but there is a bit of a food production boom in Africa. With a flatter world economy, one direction to expand is in less developed areas. (Land use, in the third world.)

    A huge thumbs up for mentioning cooler homes in hot climates. Although no architectural changes are actually needed, just a few brain cells. In South Africa we used small grates at the floor and at the ceiling which we’d open in summer and close in winter. Natural passive convection worked like a charm. (SA homes are about UK size.)

    I do notice that many newer homes have done their best to prevent natural heating and cooling. 100 years ago it was pretty common to have floor and ceiling windows as well as planting lots of deciduous trees around (smaller) homes to provide a milder household climate (cooler in summer, warmer in winter).

  24. anoilman says:

    Anders: We already have short term adaptions for ENSO. If its hot, the farmers in sensitive regions grow different crops. ENSO warnings this year have already altered many raw food prices.

    Longer term? I don’t know.

  25. > This seems reasonable for modest warming, but do we have any real idea of the possible impact of 5 degrees of warming in the next century

    I don’t :-). My (rather ignorant) suspicion is that *temperature* related changes would be slow enough to be adapted to even at the high end of 5 oC / century; I could see rather more difficult problems from precipitation related changes.

  26. Rachel M says:

    According to IPCC report part II (Chapter 26 Regional Impact North America), adaptation is only expected to offset declines in crop yields up to about 4°C of warming. This is specific for North America, but I imagine the case will be very similar in other parts of the world:

    At 2°C, adaptation has high potential to off-set projected declines in yields for many crops, and many strategies offer mitigation co-benefits; but effectiveness of adaptation would be reduced at 4°C (high confidence).

  27. graemeu says:

    I love it particularly the bit about food plants failing but poison ivy romping away and taller dandelions, More bitter salad greens will do us all a world of good. Not enough time to read all the comments but it seems to start well and then someone decided it needed more and started drawing some some pretty tenuous connections. For a lot of the human impact claims I think if you found the references they’d be rants or circular and not back to science journals. More grist to the denialist mill.

  28. guthrie says:

    How the fuck are you supposed to put evidence onto a colourful infographic? That’s not what they are for. At least it has a list of sources at the bottom.
    I agree we always need better information communicated to the public and it would be nice if we had better structures in place to do so, but really, you have to also take into consideration the many different levels and forms of communication when looking at current efforts.

  29. What makes more efficient use of land, agriculturally speaking, is bigger tractors and machinery, plus the availability of cheap oil to power them and to produce the necessary fertilisers. Can we bank on oil still being cheap in 50 years’ time?

    Add to that water shortages in some countries and an excess in others and I’d argue that agriculture will have great difficulty in producing the food required. And as fish is such a big element in the diet of so many countries there’ll surely be a shortfall to make up there. Overall, once again, it’s a risk-management issue. http://www.epa.gov/climatechange/impacts-adaptation/agriculture.html

  30. guthrie says:

    The basic idea of it seems sound enough, but whoever put it together is a moron because they’ve mixed up impacts from different geographical areas; how many americans will care how many britons get killed from excess heat? Or how many britons even know what poison ivy is?

    There is a similar problem in museums, where the information gets filtered through people with degrees in communication or something and little knowledge of the actual historical facts. The National Museum of Scotland is infamous for its error riddled information panels in the galleries.*
    This particular effort is rather similar, it’s been put together by someone who wants to communicate but thinks the media area great sources of information, and their attempts at aiming at a specific audience aren’t very good. Bringing in stuff like poison ivy is a good idea, but errors like bees is silly and missing out oceanic acidification is not helpful, although since the central point is a thermometer, that isn’t so related.

    Basically this kind of infographic thing can only be part of a wider campaign, since it can’t address the way global warming is related to so many other problems as well as not directly temperature related ones like oceanic acidification. At the moment I’d give it 5/10, with the obvious proviso that it can’t be put out in public yet until it is improved.

    * well famous as in me and people who talk to people who know stuff know about it.

  31. Pingback: What’s in store for your habitat? | RachelSquirrel

  32. Michael Hauber says:

    I think our intuition on the impact of temperature change on human comfort is misleading. For many of us our experience of warmer weather is usually linked with drier weather. Hot = high pressure, sunny skies and/or wind blowing from a nearby dry landmass. Cool = low pressure, cloudy weather and/or wind blowing from a nearby ocean. Heat is a lot less stressful for a human if it is accompanied by dry conditions than humid. For many of us we see it get up to 10 degrees hotter than average on a very hot day, and so less than 5 degrees of warming doesn’t seem so bad.

    But global warming will probably come with no reduction in humidity, and I expect the combination of heat and humidity will be quite unpleasant for anyone living in subtropical climates or warmer. When you get both high heat and humidity then evaporative cooling, shade and any other passive cooling effects start to struggle. My experience is a subtropical climate where dew points in summer are regularly in the low to mid 20s. This can be reasonably comfortable with good shade, appropriate clothing and a breeze, but only if you don’t do anything more strenuous than a gentle walk. At the extreme, a dew point of 35 is pretty much guaranteed death for a human without air conditioning. Current global extremes in dew points are about 30 degrees, so 5 degrees of warming is of serious concern. Keeping in mind that warming won’t just stop unless we do enough with Co2 reduction and/or geo-engineering, we have to seriosuly consider the possibility that eventually (in future centuries) significant portions of the world may become uninhabitable for humans without totally reliable access to air conditioning.

  33. Ian Forrester says:

    In terms of many agricultural crops it is not the rise in day time maximums which are having the biggest effect but the rise in night time maximums. AGW is of course raising night time temperatures faster than day time temperatures.

    Here is a paper on rice:
    http://www.pnas.org/content/101/27/9971.full

    And one on wheat:
    http://tinyurl.com/ledw5xl

    I’m sure that there are other crops where this is a major problem.

  34. Steve Bloom says:

    Rachel, did you check if the WGII reference is tainted by Tol?

    Re the AR5 generally, let’s not forget that some important bits have already been superceded by subsequent work.

  35. Richard S.J. Tol says:

    Readers would be advised to read Schelling’s introduction on the impact of climate change instead: http://sedac.ciesin.org/mva/iamcc.tg/articles/SC1992/SC1992.html

  36. Steve Bloom says:

    The context-free graphic Vinny provided (and what was the point of that?) shows either the atmosphere or the oceans as a sphere. I’ve seen both done. The most effective variant IMO was an animation showing CO2 emissions represented as balls maybe 10 meters wide popping into existence on a Manhattan street and then piling up. After a year (IIRC) the island and most of the rest of NYC was invisible beneath a vast pyramid of CO2.

  37. Steve Bloom says:

    What timing I have. 🙂

  38. Rachel M says:

    haha. I have no idea, Steve. Maybe Richard Tol can answer that himself.

  39. Michael says:

    Increase in chronic lung disease? – I’m very sceptical.

  40. Steve Bloom says:

    Here we go, showing both oceans and atmosphere, so my guess was correct.

    And here‘s the NYC CO2 one, very, very effective IMO.

    It turns out the folks who did both of these have some other interesting graphics. Have a look.

  41. Andrew Dodds says:

    Regarding food..

    It’s one of those problems where it seems OK as a first order problem – plant different crops, plant further north – if the only thing going on was a march of climate zones northwards.

    Problem, is, you have to contend with completely different soils – much of our best agricultural soil is the produce of glacial outwash in now-temperate zones, and won’t be shifting with the climate zones. And clear-fell any forests currently occupying those zones. But the further north you go, the shorter the growing season regardless of temperature.

    The shifting rain patterns and tendency for weather patterns to get ‘locked-in’ to drought or flood, if they stay and get worse, are going to make all forms of farming harder. And, over a longer timescale, rising sea levels will take out farmland disproportionately.

    Plus we seem to be reaching the limits of yield improvement, even with GM.

    http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0066428

    OTOH, there’s some slack in the current system – grain fed to animals, and biofuels being obvious ones. And, of course, the techno-futurist in me sees the growing of meat in vats, direct synthesis of carbohydrates and fats and other yummy developments that will use energy directly rather than going through biology..

  42. guthrie says:

    Andrew – not to mention wasteage of food before it even reaches the market.

  43. OPatrick says:

    The graphic seems confused and confusing to me and it fails to capture what I find most alarming about climate change. Aside from the already mentioned issue of ocean acidification, what it doesn’t get across is that climate change is a threat multiplier. At a time when most measures of development are improving climate change is working in the opposite direction and seems likely to cancel out some, if not all, of these developmental gains. Added instability from regional food shortages and displacement of populations and damage to infrastructure from extreme weather events has the potential to exacerbate already precarious situations.

    By breaking the problem down into bite-sized chunks like this it both gives easy opportunities for the standard ‘sceptic’ approach of nit-picking details and fails to get across the interrelatedness of the problems.

    Incidentally, I’m not sure about the direction of reading supposedly being from bottom to top, not least because the thermometer colour goes from yellow to red going down the page, which would normally suggest increasing temperatures. As I said, confused and confusing.

    Can I also register my horror at the misleading nature of the ‘coffin’ graph, where the heights of the coffins are proportional to the number of deaths represented but the areas are not.

    Are you sure this graphic wasn’t created by a ‘sceptic’ with the intention of discrediting us?

  44. O’Patrick,

    Are you sure this graphic wasn’t created by a ‘sceptic’ with the intention of discrediting us?

    Possibly, it’s happened to me before 🙂

  45. See what’s happened here? We see a graphic which has been produced (we assume) with the intention of showing the masses that they should take climate change seriously. But being truly sceptical we analyse it and find many faults with it, though we accept it was produced with good intentions. However, no commenter seems very keen on it. Now imagine if a similar style of graphic had been produced by contrarians to publicise their belief that climate change isn’t real/ won’t be bad… or whatever (and I suggest this is unlikely because, well, it’s difficult to think of any meaningful evidence they could illustrate). But if they did, can we imagine it being received sceptically by the readers of WUWT or similar?

  46. John,
    Shocking, I know. This is not how a blog comment stream is meant to work. We’re all meant to cheer and go “hear, hear, this graphic is fantastic, just what we need” (or, alternatively “boo, boo, hiss, hiss” if it’s something we’re meant to disagree with).

  47. izen says:

    It is a shoddy piece of work.

    others have pointed out that the ‘scare’ issued selected are presented with no reference to how strong the linkage is with AGW or CC or on what time-scale and at what temperature such effects might have an impact.
    It might be assumed that given the thermometer running up the middle, the position on the column might relate to the temperature, time or severity of the impact. But the positioning seems arbitrary and confused. As does the direction the graphic should be ‘read’ in. Ambiguity abounds between a thermometer which might be expected to be read from the bottom up, but the title is at the top and the references at the bottom. The red block headlines which given the emphasis should be he key points vary between the irrelevant and bathetic.

    The graphic style used, flat color blocks, very fifties, seems to be fashionable at present. Perhaps it is post-modern irony to have used the stereotypical two child family, an adolescent boy and younger blonde girl, the wife drives the children to school in an MPV, hubby has a saloon, the doctor is a balding white male and the man in the hot poor country has a Zapata moustache.The husband is always in shirt and tie, except when he is mowing the lawn!
    Other graphic malpractices from the past emerge. The confusion of vertical scale with volume is used to make the rise in oil prices look ‘bigger’. Annular pie charts to illustrate a percentage change are a strange choice. There is so much wrong with this poster it becomes tempting to think it might be an intentional example of all the things NOT to do in graphic design intended to convey information. Rather like those web pages that were always cited as examples of what to avoid. LUbois Motl always ranked high I remember.

    There are more things wrong with this, but such detailed analysis is not warranted by the subject, – it can be left for the student at home for practice! (grin).
    Whether this standard of graphic reveals an equally confused grasp of the impacts by the people who had it made is a more important question, and whether the faults and flaws should be drawn to their attention.
    But there is one final error that might not be the fault of InfographicWorld.com, below the image it says in text-
    “Source : Inforgraphicworld”
    who added the ‘r’ ?
    or is a slip towards ‘inforgetable’?

  48. Vinny Burgoo says:

    Steve B, you’re right. Thanks. Atmosphere. Not a lollipop, then.

  49. anoilman says:

    Andrew Dodds: Oh… you won’t be growing plants up in Canada.

    You’ll need to go somewhere else for that. Prairie oil is crap, and frankly Canada is getting a mix of flooding and drought. The trend in extremes for Canada’s prairies are expected to get worse.

    To give you an idea what little soil there is, its thin, sandy, and on top of hard clay. This kinda sorta grows wheat, grains, and of course hay (cow food). It is erroneous to think a more dynamic crop base will thrive here.

    Asparagus farms have 20% of the yields of their Californian counterparts. And in this case, the soil is nearly identical. However, we have vastly different seasonal variations.

    But more to the point why would American’s demand to loose jobs and enrich other nations? That sounds very un-American.

  50. Doug Bostrom says:

    Readers would be advised to read Schelling’s introduction on the impact of climate change instead: http://sedac.ciesin.org/mva/iamcc.tg/articles/SC1992/SC1992.html

    1992, and then we fell asleep. If the fossil fuel industry is encephalitic lethargica, who’s our Oliver Sacks? 🙂

  51. Doug,
    I missed that. So, Richard’s suggested reading on the impact of climate change is from 22 years ago. That may explain why he seems so far behind the times. Maybe read something more recent?

  52. Richard S.J. Tol says:

    @Doug/Wotts
    It does not hurt to know your classics. Besides, Schelling is typically decades ahead of others.

  53. Richard,
    That doesn’t really make sense. What’s of interest is our current understanding of the potential impacts of climate change. Why would reading what someone thought might happen 22 years ago of particular value? If he was years ahead of others, that would – by definition – be the ability to guess well, rather than anything else.

  54. Richard S.J. Tol says:

    @Wotts
    Just read it. Schelling is miles ahead of your cartoon.

  55. Eli Rabett says:

    We are now two decades ahead of Schelling. My how time flies when you are whacking moles

  56. Richard,

    Just read it. Schelling is miles ahead of your cartoon.

    That may be true, as the general view here is that this cartoon is pretty bad. I did actually read it (or some of it) but I still don’t quite know what to make of your “best” resource being 22 years old. I’m assuming it’s some kind of veiled (or, maybe, not so veiled) insult, as that would seem consistent with your normal behaviour.

  57. guthrie says:

    A long essay is going to be a lot more informative than an infographic; anyone who thinks otherwise is an idiot.
    I had a skim through Schelling and found it uninformative except in the most general terms, not to mention behind the times. It brings up ecosystems only to handwave the concerns away. I can find no mention of oceanic acidification. Other readers will no doubt find other examples. Suffice to say that things have moved on since it was written.

  58. What caught my eye in skipping through Tol’s suggested reading was, “In 1979, a committee of the National Academy of Sciences (NAS) (1979 p. 2) estimated the change in average temperature to accompany a doubling of carbon dioxide in the atmosphere: three degrees Celsius, with a range of 1.5 degrees to either side.” So in 35 years, climate science has increased the certainty but not the underlying message. Which is something the lukewarmers arguing that sensitivity is low should ponder on.

    Like others, I found the rest rather weak. For instance a carbon tax is dismissed because, to paraphrase, “at a level necessary to have an effect, I cannot imagine it would get through congress”. Which completely misses the point: when events change the goal posts, countries sometimes find themselves doing things they never dreamt possible.

  59. John,
    On the topic of a carbon tax, there’s an interesting post that suggests that even a high carbon tax wouldn’t have much impact, basically because if you work out what impact it would have on prices, it’s not very high. Of course, that still doesn’t mean that one could convince the US congress to impose one.

    I did a quick calculation based on my car’s emissions and – unless I made a mistake – if a carbon tax were to increase my fuel costs by 10%, it would require a carbon tax of £50 per metric ton.

  60. aTTP

    The tax you pay for the fuel of your car is, indeed, many times higher than any of the proposals for near term carbon tax – or any price for emission right of the past EU market.

    We keep on driving in spite of the high fuel taxes, but the average consumption per kilometer of cars has gone down rapidly. This decrease is probably the technical change of largest importance for the CO2 emissions of today in Europe.

  61. Pekka,

    The tax you pay for the fuel of your car is, indeed, many times higher than any of the proposals for near term carbon tax

    Indeed, I was adding a carbon tax on top of all of the other existing taxes.

    We keep on driving in spite of the high fuel taxes, but the average consumption per kilometer of cars has gone down rapidly.

    Seems to suggest that a carbon tax can work.

  62. Andrew Dodds says:

    Yes – in the UK, if we pretend that Fuel Duty is actually a carbon tax – of well over 100% (About £600/ tonne C, £2000/tonne CO2), we see that people still use petrol quite freely. Fuel economy has slowly increased (although the difference between official and real mpg seems to have increased as well), but there has been little switching to non-net-carbon fuels.

    And that’s for a highly visible day to day expense. Problem is that even with this level of ‘carbon tax’, new car depreciation completely dominates the cost of motoring for the first 5 or so years. Even with my 10-year old diesel, fuel costs are only 50%.

    A carbon tax on natural gas that doubled my heating bill might just make ground source heating or solar hot water an interesting alternative, but it would also freeze a lot of grannies. Electricity is even worse.. and in both cases it’s possible to avoid carbon taxes by spending a big chunk of money to go off-grid to some degree, so the impact falls on those who are least well-off.

    At least that’s my take, it seems like a lot of Carbon Tax proponents are of the ‘massless, frictionless pulley’ class of economists who assume away any awkward realities in favor of a solution that ‘will work, but we can’t say how’. A Carbon Tax certainly helps and would help refine solutions, but I don’t see how it fixes the problem in reasonable time. Never mind that also, as Australia shows, the cheapest way for the coal industry to react to a carbon tax is to buy the government and get it repealed. The free marketeers seemed to miss that one..

  63. Carbon tax has influence, when there are alternatives that add only little to the cost calculated excluding costs. In most cases the influence is slow as it is affecting energy efficiency of the total housing stock.

    In the case of fuel efficiency of cars many factors have their role in the speed of development, existing and anticipated climate policies are among them, the high and variable price of crude oil is another. General technological development has contributed also very much.

  64. Andrew,
    What you says sounds about right. A carbon tax is a free-market-like solution. Make us pay for the cost of emitting carbon. However, we can’t simply do that because it will have some serious negative implications for those on low incomes. You’d like to think that this would lead people to conclude that the free-market can’t solve everything and that we should therefore think of something that could be effective but that doesn’t negatively impact those who can’t afford to pay more for energy. Of course, what seems to happen is that people argue that the free-market is the only way to solve this and that since we can’t impose a free-market solution, we shouldn’t do anything (generalising and exaggerating for effect).

  65. Andrew
    £600/ tonne C is about £164/tonne CO2.

  66. My understanding of a carbon tax is that it should be revenue neutral. In other words the money raised should be spent first and foremost in insulating homes and improving the efficiency of the built environment in general. It’s quite possible with a relatively modest outlay to make a home approach being carbon neutral. There’s enough waste heat from necessary equipment like cookers and fridges, never mind computers and TVs; and even from body heat.

  67. John,
    Yes, I think that a carbon tax should be revenue neutral is generally correct. What I’ve never managed to establish is how this impacts the different sectors of society. Revenue neutral just means overall, so there will still be some who lose and some who gain. If I was being cynical I would guess that the wealthy would lose and those on low-incomes would gain, while what we’ll be told is the opposite of that.

  68. John,
    You present an odd interpretation of the concept revenue neutral. My interpretation is that it means that the new tax is introduced as part of a wider package that does not change the total revenues of the government.

  69. The wealthiest don’t need to suffer when it comes to their homes. If, for instance, all VAT was removed from insulation and the labour to install it, the wealthy—who often have the biggest and least-efficient houses—would reclaim some of the money they lose heating their swimming pools. I see the carbon tax as creating a pressure to reduce energy use, and not just carbon-based energy. Combating climate change is about doing what we do now (with a few exceptions like flying) but much more efficiently.

  70. Pekka,
    I assumed he meant that it would pay for things that we might want to do anyway and that also increase energy efficiency. Of course, we could choose not to do these things and hence not to raise the tax to do so, but if we were to do these things, a carbon tax could pay for it.

  71. Your “interesting post” is entitled “Is a Carbon Tax Sufficient to Reach Zero Carbon?” which is to miss the point. The point (from the pure economics POV) is to internalise the externalities. Ie, you get to pay for emitting your carbon. But the choice of pay, or don’t emit, is up to you. This is different from a carbon permit system.

    > how it fixes the problem

    That would rather depend on what you see as the problem, no?

    > a carbon tax should be revenue neutral is generally correct.

    I hope by that you mean “I think that’s a good idea”, or “is politically a correct solution”. AFAIK, there’s no economic reason for it.

    > My understanding of a carbon tax is that it should be revenue neutral. In other words the money raised should be spent first and foremost in insulating homes and

    You’ve just conflated two totally separate things. Being revenue neutral isn’t at all the same thing as hypothecating the revenues for particular projects.

    WRT ATTP’s point about who-loses, my preference would be some form of support for those on low / no incomes (not an explicit fuel subsidy of course, that would be really stupid).

    > people to conclude that the free-market can’t solve everything

    Careful. You’re caricaturing your “opposition”. No-one believe the free market can solve everything.

  72. It’s better to use the words to mean, what they have meant before.

    A revenue neutral tax does by definition not provide any extra funds for spending in support of efficiency investments.

  73. Pekka. As I understand it the proposal for a revenue-neutral carbon tax, is that the money that enters the government coffers is spent on grants to assist people in insulating their homes plus grants to industry to reduce their emissions.

  74. William,

    The point (from the pure economics POV) is to internalise the externalities. Ie, you get to pay for emitting your carbon. But the choice of pay, or don’t emit, is up to you. This is different from a carbon permit system.

    Yes, that’s how I’d understood it too, so good point. On the other hand, the post was really trying to illustrate that it was likely to be ineffective if it were all we were to rely on. I don’t have a good sense of how effective a carbon tax would actually be, but certainly think that it would be a start.

    Careful. You’re caricaturing your “opposition”. No-one believe the free market can solve everything.

    Indeed, I was caricaturing my opposition – as I thought my parenthetic comment indicated 🙂 Although, to be clear, I don’t know if such people are my opposition (I don’t think I have a strong position in this regard), but I take your point.

  75. Pekka,

    A revenue neutral tax does by definition not provide any extra funds for spending in support of efficiency investments.

    Fair enough, although – pedantically speaking – it could be true if we start spending on energy efficiency before introducing a carbon tax 🙂

  76. William,
    For any single participant tradeable emission permits are equivalent to a tax as incentive. The cap in permits affects only the total, and through that the price that the participants see. The problem of such permits is that their price may be difficult to predict and therefore a less efficient incentive than a more predictable tax.

  77. In a rational system, there’s no reason to couple revenues from carbon tax to spending in investment support. People, who like both, may like such coupling, but getting others to agree on even one may be easier without such coupling.

  78. Having just read up on this I see Pekka’s point. In the UK carbon taxes and ‘Green Deal’-type initiatives are often discussed together but I see that in the States the idea is that a rebate is provided to taxpayers to spend as they like. That might be ‘free market’, but is it not also redistributing wealth to a degree, which seems to be ideologically contradictory?

    Also the problem with that US approach is that the temptation is to spend the rebate on activities that emit carbon rather than invest it in things which reduce one’s exposure to the carbon tax. Insulating one’s home requires an investment which is greater than any rebate in the short term and people tend not to think too far ahead.

  79. > For any single participant tradeable emission permits are equivalent to a tax as incentive

    Not quite. In the tax version, you can emit as much as you like, as long as you pay. In the permits scheme, you can only emit as much as you have permits for. If you assume infinite numbers of permits can be purchased at the tax price, then its equiv. But in most schemes, the number of permits is limited. Indeed, that’s usually what the schemes are sold on: “we know how much CO2 it would be good to emit, so lets issue permits up to that level”.

    > ineffective if it were all we were to rely on

    I think you’ve missed my point. You’re adding an implicit “ineffective, defined as ‘not reducing our CO2 emissions to level X'”. But that’s not what the carbon tax is for. Its internalising externalities. This is different.

  80. William,

    You’re adding an implicit “ineffective, defined as ‘not reducing our CO2 emissions to level X’”. But that’s not what the carbon tax is for. Its internalising externalities. This is different.

    Okay, yes, I see what you mean. A carbon tax is simply associated with the cost of emitting carbon, and – by itself – has no actual goal. We simply pay and the market evolves to optimise how we emit carbon (i.e., we’ll emit less if it is worth doing so).

    However, it still seems as though a carbon tax by itself does not guarantee that we will reduce our emissions in a manner that is consistent with minimising the risks associated with climate change. So, I agree that this is not what a carbon tax is for, but that would still imply that if we have a goal of minimising the risks associated with climate change, that it – by itself – may not allow us to achieve that goal. Of course, that isn’t an argument against a carbon tax. It’s simply an argument against imposing a carbon tax and then doing nothing else.

  81. I think we’re close to agreement. You’re looking to “minimis[e] the risks associated with climate change” whereas I think the default optimal-design carbon tax would internalise the costs associated with the expected, or average, climate change (per CO2). Asking to minimise the risks is probably too much (it also depends on what you mean by it. If you mean, just the risks of climate change, then its clear than the way to minimise this is to emit no more CO2. That’s not a reasonable interpretation. So I’ll assume you mean “minimise the risks to human (and other) wellbeing, associated with the costs of climate change, and the costs to economic gains foregone from CO2 reduction”. With that second formulation, I think its likely that emissions permits fail your test. As to all the various market-distorting mechanisms currently used.

  82. William,

    So I’ll assume you mean “minimise the risks to human (and other) wellbeing, associated with the costs of climate change, and the costs to economic gains foregone from CO2 reduction”.

    Yes, I didn’t mean minimise with respect to the impact of climate change alone, I meant minimise with respect to all the risks associated with climate change (including the risks associated with acting to combat climate change).

    I think the default optimal-design carbon tax would internalise the costs associated with the expected, or average, climate change (per CO2).

    Okay, that’s a good point that I’d somewhat failed to realise. If I understand you correctly, a properly implemented carbon tax would evolve depending on a continuous assessments of the cost of emitting carbon. So, if it has little effect on emissions and the assessments indicate that the cost of emitting carbon has risen, then the carbon tax can rise accordingly. So, maybe I am wrong that it alone can’t do anything. Possibly I’ve included a pragmatic view that we will not allow it to rise beyond some level. If we don’t constrain the level of the carbon tax and are able to assess the future cost with some level of accuracy, then I guess it could well be effective on its own.

  83. Here’s a question for someone who may know more about this than I do (not difficult I hear people say – and they’d be right 🙂 ). Presumably the future cost of emitting carbon is non-linear in some sense. If we stop emitting carbon today (and I’m not suggesting we do) atmospheric concentrations will decrease. Therefore, there must be some level of emission that does no damage in the future relative to today (i.e., there must be a rate that would simply fix concentrations at today’s level). On the other hand, there must be some level of emission (assuming we could sustain it) that would be catastrophic. So, does anyone know firstly if I’m right, secondly, if this is taken into account, and thirdly, how they do so?

  84. Marlowe Johnson says:

    do you want certainty on mitigation costs or emission quantities? you can’t have both. that’s the trade-off between a tax and C&T in principle. of course in reality neither approach is so straightforward. pols being pols aren’t terribly inclined to set tax schedules or emission caps over more than a few years as constraining future government regimes is generally frowned upon. which makes one wonder how useful those mid and long-term emission reduction targets really are…

    on a practical level the trade-off between the two comes down to politics. is it easier to sell the public on the simplicity of a revenue neutral carbon tax or create a motivated political constituency with a C&T system, i.e. wall street vs main street? fools are full of certainty while all I have are doubts 😉

  85. > that’s the trade-off between a tax and C&T in principle

    Its not news, either. For example http://scienceblogs.com/stoat/2011/06/06/carbon-tax-now-1/ (wade through the introductory blather and get to the para starting “There is a fundamental difference between carbon taxes and permits…”).

  86. Marlowe Johnson says:

    the point for dim weasels to remember is that the difference in practice isn’t so fundamental…

  87. William,

    It’s difficult to imagine a situation, where the number of permits would not be sufficient for any single participant, and even a situation, where the needs of a single participant affect significantly the price on the market. Therefore the price is the only incentive and that’s equivalent to a carbon tax assuming that the price level is the same and known equally well.

    It’s rather widely agreed that a carbon tax would be essentially more efficient due to the difference in the predictability of the cost. The IPCC WG3 reports include this conclusion as do numerous other reports. The reason for having cap&trade as the basis for the Kyoto agreement is only in the fact that agreeing on a harmonized tax was deemed impossible. Even EU could not agree internally on that, because EU needs an unanimous agreement for harmonized taxes, but not for cap&trade.

  88. If there really were a specific level of emissions that must be reached, using that as cap would be natural, but what we really know is that the risks grow with the amount of emissions over a wide range. Therefore there real practical goal is to reduce emissions as much as we can taking other realities into account. It’s easier to figure out a level of carbon tax that represents “the other realities” than to fix the gap in a way that gives a strong incentive but does not lead to so severe problems that it’s given up.

    What has happened in Europe is that the cap&trade approach has resulted in so low price for permits that it has presently almost no influence as an incentive. It could have happened that the cap had been so tight that keeping it had become politically impossible. It’s difficult to avoid both errors in deciding on the cap, but it’s at least technically easier to decide on a level of tax that has a clear effect but is not too severe for the economy.

    As all decisions are difficult over very long periods, an approach should be chosen, where the level of tax can bee adjusted based on further understanding, but is still predictable enough for serving as an efficient incentive. My proposal is to fix the level always for five years to come, and to decide annually for the next new year to be included in the period of known tax rate.

  89. Chris Hope says:

    This has developed into a very good discussion, and I think Pekka and William have said most of the things I would want to say, so I will confine myself to answering the question about the evolution of the carbon tax over time. The modelling does show that it will increase in real terms over time, by about 2-3% per year under most emission scenarios. This was in the 2007 IPCC report. The relevant section can be found at http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch20s20-6-1.html
    @cwhope

  90. Chris,
    Thanks for the comment. I had a couple of other questions, if you have time. What I was unsure of was whether or not the models tried to include the impact of the carbon tax itself. In other words, are the emissions pathways for each model run fixed in advance, or do they evolve according to the carbon tax? My understanding is that it’s the former, rather than the latter.

    Given that, I’m not sure why the carbon tax changes with time. If the emission pathway in each model run is pre-defined, doesn’t that mean that the carbon tax will be the same at all times (inflation adjusted) or is it defined in a way that means that it changes with time.

    It is possible that neither of these question is well-posed 🙂

  91. All graphics like these fail in identical ways, for identical reasons:

    * Impacts are complex (hundreds or thousands of major discrete impacts, not a dozen)
    * Impacts are uncertain (we really don’t know how a Cretaceous climate will affect food production)
    * Impacts will be strongly affected by the human responses (adaptive and maladaptive both)

    So what they end up with is a laundry list of bad things some study, somewhere, has predicted, without any indication of the level of confidence, or objective measure of the extent of the damage, or any suggestion that the list is comprehensive or complete.

    The fault ultimately is in our poor understanding of risk. The ideal poster would say:

    * We don’t know exactly what the impacts will be.
    * Since our civilization and the natural world are adapted to this climate, from our perspective they likely will be bad.
    * Most of the impacts we’ve tentatively identified are, in fact, bad.
    * Given the above, forcing the climate of the one and only climate upon which seven billion humans can live out of the range it has been in since humans came down from the trees is colossally stupid.

    . . . but pitched at a third-grade level. Good luck!

  92. Chris Hope says:

    Different models do different things. In PAGE09 you specify an emissions pathway, and can then calculate the social cost of CO2 (= the theoretically correct carbon tax) in each analysis year. If you believe the carbon tax will reduce the emissions, you can input the new emissions path and re-calculate the social cost of CO2 in each year. You can even ask the model to calculate the optimal path of emissions that minimises the expected net present value of impacts and mitigation costs, and then calculate the social cost of CO2 in each year for that path.,

    In DICE, I believe this is automated more and the model calculates the optimal emissions path and carbon tax simultaneously (but with a much less good treatment of uncertainties, non-CO2 greenhouse gases etc).

    The reason the social cost of CO2 increases over time is quite simple. It is because a tonne of CO2 released in 2050 will have a bigger effect on the climate at the time impacts are likely to become really severe than a tonne released in 2014. Most of the 2014 tonne will have been removed from the system by the end of the century, whereas most of the 2050 tonne will still be around.

    @cwhope

  93. Chris,

    The reason the social cost of CO2 increases over time is quite simple. It is because a tonne of CO2 released in 2050 will have a bigger effect on the climate at the time impacts are likely to become really severe than a tonne released in 2014. Most of the 2014 tonne will have been removed from the system by the end of the century, whereas most of the 2050 tonne will still be around.

    Okay, that makes sense, thanks.

  94. If the model (or other analysis of future) is capable of handling all dynamic effects of technology development and economy there are probably many different factors that influence in the direction that starting with a lower tax rate and raising it later is favored – and some that have the opposite effect. The effects that I have in mind include:
    – Disruptive effects on economy of sudden introduction of a high carbon tax.
    – Availability of low cost options at the beginning and the economic advantage of starting by the implementation of those options.
    – Influence of technical development that disfavors early introduction of technologies that have presently relatively high costs, but lower in the future.
    – The value of the real option of leaving investment decisions to a time of more knowledge.
    – The continuously improving understanding of the consequences of climate change.
    – The experiences collected from the early phase help in determining the effectiveness of the incentives.
    – Knowledge that higher tax rate is expected in the future favors investment in R&D of better technologies for the future.

    All the above favor the solution of a modest initial tax rate that’s expected to rise in the future, but this solution does not maximize the early impacts on emissions, which is the main argument against it.

    Starting with a modest tax rate creates immediate incentives for action and allows for ultimately very strong incentives without the risks that a sudden introduction of high carbon taxes create for the stability of economies.

  95. I agree that starting with a modest rate and raising it is good. It has political advantages too: people learn that all the overheated rhetoric about destroying jobs and the economy is wrong; hopefully they see that it functions efficiently; hopefully (if it is implemented as revenue neutral) they see other taxes falling, and learn to trust that this will happen.

  96. I agree that starting with a modest rate and raising it is good.

    Indeed, short, sharp shocks are rarely a good idea. Just hope that we aren’t forced into one, though.

  97. Joseph says:

    I wonder if anyone has seen this paper reported on here:
    http://desmogblog.com/2014/08/18/major-disasters-linked-extreme-weather-climate-and-water-hazards-rise

    Paper
    http://www.wmo.int/pages/prog/drr/transfer/2014.06.12-WMO1123_Atlas_120614.pdf

    I wonder if this could be considered conclusive evidence that AGW has resulted in an increase of extreme weather related events?

  98. Joseph,
    I haven’t read it in detail, but my guess is that if you were to ask Roger Pielke Jr he would tell you that if you correct for GDP and other non-climate related factors, there’d be no trend.

  99. This extended cartoon is a sobering reminder of the adversary relationship of advertising and science.

    Strings of predictions about the human consequences of a delta T of +1 C or +4C are adduced at risk of readers reflecting on the degree to which the climate of thefuture can be experienced today by traveling 1 degree to 4 degrees equatorward, or as many thousands of feet downhill.

    Inflicting poison ivy on Canada sems a small price to pay for replacing it with Virginia creeper Maryland

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s