Carbon budget constraints

I’d been meaning to highlight a statement from Kevin Anderson for quite some time. A brief lull in postings gives me a chance to do so. It relates to the Paris goal of keeping global warming below 2oC. I haven’t double checked the numbers, but they seem reasonable and I’ve included an animation from Carbon Brief at the end of the post that nicely illustrates how difficult this is becoming.

I’ve highlighted some aspect of Kevin Anderson’s statement that I found particularly important (I transcibed it, so any errors are probably mine).

Once highly optimistic assumptions are made for curtailing deforestation, increasing afforestation and reducing process emissions from industry (primarily cement and steel), the energy-only carbon budget is highly constrained. In the absence of heroic assumptions about negative emissions (increasing the budgets) and ignoring additional positive feedbacks (reducing the budgets), OECD nations need to be fully decarbonised by 2035, with the non-OECD nations following suite in the 2050s.

Transposing this into mitigation rates (dictated by the budgets), requires OECD nations to be delivering 10% annual cuts from about ~2018 onwards. Turning to non-OECD nations, on aggregate they need to reach a peak in emissions by the early 2020s before ramping up to ~10% p.a. by the early 2040s. Add up all of this, and the collective budgets are broadly consistent with a reasonable chance of 2oC.

It is important to note that the nature of the carbon budgets mean that any failure to deliver deep mitigation rates in the near term (from a high starting value) very rapidly increases future rates to completely unattainable levels. Delay is not an option and our 2oC mitigation analysis needs to be informed by this.

We can of course throw our hands in the air and declare the implications of such emission constraints are too onerous for us high-emitters to contemplate. But then we need to be honest and say to our and others’ children, as well as many millions living in poor and climate-vulnerable communities, that we have chosen to renege on the Paris commitments. This is an authentic position, allowing others to consider the implications and make whatever contingencies they can to deal with the chaos of the 3-5oC of warming we’ve decided to bestow upon them.

Carbon brief has a recent article about carbon emissions that is relevant. It includes a figure showing how the emission pathways consistent with a 66% chance of staying below 2oC depend on the year in which emission reductions start (or could have started). An animation of that figure is in the tweet below; it’s clearly getting increasingly difficult.

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26 Responses to Carbon budget constraints

  1. ATTP – great post. Kevin Anderson makes an additional point on the ethics implied by the carbon budget. Every time we choose to take a high carbon option (fly business class, or fly too often … or fly at all?), we are saying to people in a developing country: we have taken this extra bit of budget, so there is less left for you. It is a pretty strong ethical argument. Especially as he also makes the point that if the world’s top 10% of emitters (people) chose to reduce their emissions to the level of the average EU citizen, the the global emissions would be reduced by a staggering 33%. That is hardly sackcloth and ashes.

  2. Richard,
    I also noticed this today, which maybe should be widely considered.

  3. Steven Mosher says:

    “This is an authentic position, allowing others to consider the implications and make whatever contingencies they can to deal with the chaos of the 3-5oC of warming we’ve decided to bestow upon them.”

    Just for clarity I wish that the carbon brief chart cleared out the ‘woulda coulda” parts of the graph, spilt milk and all. What would be more instructive is seeing what year is the point of no return,

  4. T-rev says:

    Just as a follow up, I always baulk when I see the 66% chance. Is anyone ok with that risk level ? If I had a 33% chance of dieing from crossing the road I’d probably reconsider. What are the 95% & 99% chances ??

  5. T-rev,

    What are the 95% & 99% chances ??

    Can probably work it out from the table in this post. I would estimate that a 95% chance would require no more than about 500GtCO2 since 2011, of which we’ve already emitted about 240GtCO2.

  6. T-rev, you do not die when crossing the 2°C threshold. There will be serious consequences before and gradually worsening consequences above.

    The 2°C level is not a brick wall we crash into. That is what I do not like about this whole budget approach.

    What is good about the budget is that is clearly shows that CO2 emissions are a cumulative problem. The damage has been done and we need to get to almost zero emissions to stop it from getting worse. It is not that when we do not like the climatic changes, we can stop emitting CO2 and go back to the old climate. No, that is the climate for keeps.

    I like the spilt milk. It shows how much harder the problem has become due to crony capitalism and the mitigation sceptical movement. It is about time to return to reason.

  7. Steven Mosher says:

    “I like the spilt milk. It shows how much harder the problem has become due to crony capitalism and the mitigation sceptical movement. It is about time to return to reason.”

    my sense is it diverts conversations into unproductive forks.

    you can do another chart for that

  8. The majority of people who come to this great blog (ATTP) like data and can interpet complex diagrams. My experience with ‘people in the street’ is that they find themselves overwhelmed with complex arguments and data, which many of us take for granted. I used to simply reuse graphics from IPCC etc. in my talks. Now I reference them in my notes, but try to simplify, without losing the essence or integrity of the science. On Victor’s point

    What is good about the budget is that is clearly shows that CO2 emissions are a cumulative problem

    Is powerful. But there a few steps – what I call the 3 most important facts – for people in the street to understand before they can really appreciate the importance of carbon budgets. I tried using financial terms “deficit” and “debt” as analogues for “emissions” and “atmospheric concentrations” at a talk I gave last week and it seemed to much appreciated.

    Deficit, Debt and stalling carbon dioxide emissions

    I want to refine this further so any suggestions, please comment on this post ^^^. And thanks to Rabett Run for his simple but truthful graphics.

  9. Richard,
    What you’re highlighting is how difficult science communication can be. Those who are comfortable with numbers and graphs often think we should introduce more complexity into the discourse. However, there are those who are not comfortable with numbers and graphs and for whom one has to find more innovative ways to communicate. There’s not a simple formula for how best to communicate publicly, in my view at least.

  10. I agree. In many ways, the communications part is the hardest part of all.

  11. Ed Davies says:

    Just getting people to understand what’s said in this tweet would help a lot: https://twitter.com/AndrewDessler/status/930434795254849536

    “Great turn of phrase by my colleague Yangyang Xu about future climate:

    If emissions are fixed, atmospheric CO2 is still increasing.

    If atmospheric CO2 is fixed, temperatures are still increasing.

    If temperatures are fixed, sea level is still increasing.”

    Without that understanding, they’ll have a very hard time getting their heads round those graphs.

  12. Ed,
    Yes, that’s a very succint summary of the basic situation.

  13. izen says:

    @-“OECD nations need to be fully decarbonised by 2035, with the non-OECD nations following suite in the 2050s.
    Transposing this into mitigation rates (dictated by the budgets), requires OECD nations to be delivering 10% annual cuts from about ~2018 onwards.”

    There is something wrong with the use of the word ‘need’ in this statement.

    I expect there are technological paths from reductions of 10% a year. With argument over the details.
    But the rate of change required politically, economically and socially is not represented in the historical record except, in times of war/famine/plague.

    The graph makes the inherent improbability of such a future path more obvious. Are there any examples in the past where a key economic and social component of modern society was abandoned more rapidly than it was adopted? Took over a century to abandon slavery.

    I am unable to see any credible path without major changes to the political and economic systems that results in all the OECD nations cutting their carbon footprint by 10% every year. That degree of flexibility has not been a feature of our current global trade and local political systems.

    This ‘need’ might be an easier sell –

    OECD nations need to establish a permanently occupied Lunar colony of at least 100 people by 2035, with the non-OECD nations following suite in the 2050s.
    Transposing this into space flights (dictated by the budgets), requires OECD nations to be delivering 10 astronauts annually from about ~2018 onward.

  14. izen,

    There is something wrong with the use of the word ‘need’ in this statement.

    Well, yes. The document on which this is based is – I think – here (although, this is EU, rather than OECD, focussed, but I suspect it would be similar for the OECD as for the EU).

  15. The Very Reverend Jebediah Hypotenuse says:

    SM:

    Just for clarity I wish that the carbon brief chart cleared out the ‘woulda coulda” parts of the graph, spilt milk and all.

    my sense is it diverts conversations into unproductive forks.
    you can do another chart for that

    It takes some mighty big Climateballs(tm) to tone-troll a Carbon Brief graph when you’ve already produced an entire
    diversionary treatise of unproductive forks.*
    “It will swamp the conventional wisdom on climate change.”
    But it doesn’t change the science.
    *Customers who bought this item also bought items by Steyn, Montfort, Singer, Idso, Plimer, Solomon, and Spencer.
    Personally, I like the spilt milk too.
    It shows the astonishing extent of the puddle of milk, and just how many paper towels teh Donald would have to throw to the crowd in order to clean up the mess as a function of delaying action.
    In fact, without that ocean of historical ‘woulda coulda’ the graph would not as clearly illustrate that once the crying is over, you can see the soon-to-be-spilt milk in an udderly new light.
    I’ll see myself out.

  16. pete best says:

    Everyone was disappointed yesterday when the UK Budget has slashed growth forecasts to 1.5% which means less of everything that a country needs to provide for its people everything they need apparently. There are so many issues related to what Kevin Anderson is saying. Yes from a purely scientific point of view I am sure it all looks like we can cut emissions by 10% per year until it is done but in REALITY we know it not plausible, we all know this!

    We all know that only 20% of our total energy in use today comes from electricity and it needs to be 80% in the time frames outlined. OK so all car drivers can go and buy and Tesla (wealthy) or a Nissian Leaf/Renault Zoe (no so wealthy) and try that but flying, HGV, the bus and coaches and shipping arnt going to be so easy (yes we know about the TESLA truck etc) but other aspects of transport wont be so easy so what other options are there. Cancel XMAS (70% of all gifts etc bought this time of year), cancel holidays, cancel sports events? Look to our life styles in the short term or just say well they arnt doing anything so why should I.

    I dont think any one wealthy or with a need to travel regularly is paying any attention personally so 2C isnt likely and 3-5C more likely so lets prepare realistically for that instead!

  17. Willard says:

    Speaking of communication, it could be worse:

    Marina Della Giusta and colleagues at the University of Reading recently conducted a linguistic analysis of the tweets of the top 25 academic economists and the top 25 scientists on Twitter. (The top 3 economists: Paul Krugman, Joseph Stiglitz and Erik Brynjolfsson; the top 3 scientists: Neil deGrasse Tyson, Brian Cox, and Richard Dawkins [sic.].) Ms Della Giusta and her colleagues found that the economists tweeted less and had fewer Twitter conversations with strangers. I sympathise, but nevertheless the scientists managed it and the economists did not. The economists also used less accessible language with more complex words and more abbreviations. Both their language and their behaviour was less chatty.

    https://www.ft.com/content/41fd4b04-cf86-11e7-9dbb-291a884dd8c6

  18. It would be nice to see the data behind some of these smooth, global mitigation paths.

    For instance, if you look closely at (zoom in and track) at the Carbon Brief graphic (on their website), and trace the annual reductions rates along any of those paths – but for illustrative purposes here, I am going to use the dark purple line which equates to “if we start (peak) in 2015, in 20xx emissions need to fall by Y%” (a box opens if you keep your “mouse” on the line and move along it year by year…)

    In the early years of the “if we start in 2015″/dark purple path, the required reductions are, for instance 2% in 2018. But by 2024 it is 5%, 2032 is 7%, 2050 is 9%, etc.

    Without knowing how Robbie Andrew at CICERO is doing this, you are left wondering why you wouldn’t just apply a single rate, which would, of course, necessitate that current generations do more (percentage-wise) (quelle horreur!) than these plots imply, but the same (again, on a percentage basis) and what would be asked of future generations.

    Now, you could potentially argue that even at lower percentage decreases early, the current generations still have to make large absolute reductions, but this is where you get into Kevin Anderson’s arguments.

    Such as, we (current generations, especially the wealthy) have the lowest-hanging fruit in terms of emission reductions. Electrifying our urban-travel cars, converting to geothermal heating and cooling, flying a few times less each month, etc. Whereas the future is going to get stuck having to solve far more pernicious, stubborn problems – like, how is agriculture ever going to be zero emissions? what about getting satellites into orbit, or conducting search and rescue or fire-fighting missions, on and on… yet we would be expecting them to solve these even faster than we can stop heating our patios with gas heaters?

    And Anderson is further saying that there is some differentiated responsibility amongst current populations, so even if you have globally modest reduction rates, certain population groups have to lead with staggeringly high rates (or else, as you quote him saying “declare the implications of such emission constraints are too onerous for us high-emitters to contemplate”)

    Anyway, I am about to go join a group that will be sitting outdoors on a patio in Toronto in late November. So I am rushing off and not quite nailing my point. Except to say that even when we see mitigation curves that look preposterously steep (like the Carbon Brief one), the reality is that if you peak underneath the covers at the underlying data, there always seems to be hidden assumptions lurking that make it seem easier than it is likely to be in reality (e.g. assumptions for BECCS, or sacrifices by future generations, etc.)…

  19. Ragnaar says:

    “…requires OECD nations to be delivering 10% annual cuts from about ~2018 onwards.”

    To try to get a handle on what this means, apply it to each of us personally. Seems daunting to me. But an approach with some merit if individuals do this. Do this despite anything their governments may do. The market demands change because of individuals. It’s an old guard hippie approach.

    Another approach is to vote for this happen. To rely on politicians to make this happen. However, 2016 had that one skidding into the ditch in the United States. Something like this is to have politicians make businesses do this. And that has happened. Electrical utilities are reacting to that.

    As mentioned by others, electricity might be 25% of the problem and our gains are mostly related to that sector. Transportation remains to be fixed to meet this 10% annual reduction. This is the migration. Working from home for some, moving closer to work and/or public transportation. Rebuilding rail freight transportation. Cutting back on air transportation of all things. The biggest hammer to swing here is gasoline and diesel taxes. Tripling them would get peoples attention.

    We are looking for a path here. Sometimes that is the retreat from and management of sea level rise.

  20. russellseitz says:

    Richard Erskine notes “Kevin Anderson …makes the point that if the world’s top 10% of emitters (people) chose to reduce their emissions to the level of the average EU citizen, the the global emissions would be reduced by a staggering 33%. That is hardly sackcloth and ashes.”

    Does this calculation include the millions migrating annually into the EU from nations with lower emissions?

  21. pete best says:

    Does this calculation include the millions migrating annually into the EU from nations with lower emissions?

    why does it need to as he is talking about the top 10% of emitters globally of which nearly all reside in western countries. Considering the worlds population is 7 billion you millions of migrants doesnt really warrant much of a carbon issue relative to the top 10%.

  22. Chubbs says:

    With Trump in office here and a general lack of urgency elsewhere, limiting warming to 2C is looking very unlikely. On a more positive note with continuing cost reduction and increasing economic scale: wind, solar, batteries etc. are all looking increasingly competitive vs fossil fuels. The development of non-fossil alternatives has been facilitated by largely uncoordinated government policy/subsidy over the past 20 years. Think what could be accomplished by a coordinated global effort to push these technologies. Instead of focusing communications on the negative implications of an ever diminishing 2C carbon balance. Favor a more positive approach, advocating a faster push to the winning technologies and reduced support for the laggards like carbon capture. Of course a carbon tax would accomplish this, but increased subsidy for winning technologies would also work. Goal would be to reach a point when the economic cost of replacing fossil fuels gets low enough to spur rapid action.

  23. Ed Davies says:

    As Chubbs says, the cost reductions of wind, solar, batteries are making them increasingly competitive. There are two problems, though, with relying on purely market-lead approaches:

    1) Wind, PV, etc, will beat fossil for new electricity production in many places but it’ll be much harder to displace fossils where they’re already in place such as existing electricity production and non-electricity use like transport (air travel particularly) and process heating.

    2) The bootstrap process of switching to renewables will itself cause a lot of carbon emissions. Your first year’s production (guess at the quantity) from a PV plant goes to making PV panels to replace the coal-fired generation which would otherwise be used for the second and subsequent years. Maybe in the long run (50 years or more) renewables will give us copious quantities of energy but if we’re to stay within the available carbon budgets during the switch over then energy use will need to be reduced. That’ll take a real social change, not just fiddling with taxes to put the right slope on the market.

    That’s not to say that carbon taxes or subsidies for new technologies are a bad idea, just that they will likely not be sufficient on their own. What I think carbon taxes will help with most is stopping other measures from having perverse effects like the UK RHI (renewable heat initiative) which resulted in places being heated more.

  24. russellseitz says:

    “why does it need to as he is talking about the top 10% of emitters globally of which nearly all reside in western countries. Considering the worlds population is 7 billion you millions of migrants doesnt really warrant much of a carbon issue relative to the top 10%.”

    The point is that apart from growing the population of high per capita emitters, emigration from low energy nations like Somalia, Afghanistan or Kiribati, to high carbon consumption ones like Austria, America or Australia automatically amplifies the carbon footprint of those resettling – in the most egregious cases , by more than an order of magnitude.

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