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Why Paris climate pledges need to overdeliver to keep warming to 2C

Posted on 12 July 2016 by Guest Author

This is a re-post from Carbon Brief by Dr Joeri Rogelj, a research scholar at the International Institute for Applied Systems Analysis (IIASA) in Austria. Rogelj was recently awarded the inaugural Piers Sellers Prize for world leading contribution to solution-focused climate research.

Last year’s Paris Agreement is considered a major global step in addressing the threat of climate change.

It was a diplomatic victory to bring 195 governments together to agree a goal to limit global average temperature increase to “well below 2C” relative to pre-industrial levels, and to “pursue efforts” to limit it to 1.5C.

It was a similar tour de force that 186 parties submitted “intended nationally determined contribution” (INDCs) in the run up to Paris. INDCs set out each country’s contribution to cutting greenhouse gas emissions in order to meet the collective global temperature goal. The INDC process succeeded in overcoming decades of hesitation across the international community.

Moreover, every five years, these contributions are to be updated or renewed, steadily increasing in ambition.

But accompanying this success came a set of puzzling questions: what do the INDCs add up to in terms of global emissions reductions? Are they sufficient to keep warming to well below 2C? If not, what temperature increase are we heading for? What about 1.5C? And, are the INDCs at least a step in the right direction?

An added complication is that INDCs don’t all follow the same approach. Some countries’ emissions pledges are conditional on receiving funding, for example, while others depend on the growth of their economy. This is why various studies (pdf) addressing these questions have often come up with different answers.

Our new paper, just published in Nature, provides some clarity on this issue by carrying out a “meta-analysis” to see what conclusions we can draw from ten of these studies.

And to cut a long story short, the INDCs alone do not keep warming to well below 2C.

Similar level of effort

The current INDCs cover the period up to 2030. To estimate warming over the entire 21st century, scientists have to make assumptions about what happens beyond the INDCs.

We identified three main possibilities for climate action after 2030: it stalls, it continues at a similar level of effort, or it accelerates.

It’s worth noting that the Paris Agreement states that future “nationally determined contributions” (NDCs) – the successors to INDCs – will need to increase in ambition. Stalling of emissions cuts would not be consistent with the ratchet mechanism within the agreement. This, therefore, leaves two options: continuing or accelerating action.

In our analysis, we first we assume that action continues after 2030 at a level similar to the INDCs.

How such a “similar level” is determined is another point of discussion – and will likely pop up as an issue when countries submit their future NDCs as part of the Paris Agreement. For our purposes, we assumed that the level of effort needed to achieve the INDCs would be continued until 2100.

Our findings suggest that extending the current INDCs out to 2100, global average surface temperature would rise to 2.6-3.1C, relative to pre-industrial levels.

This is the median estimate, which means there’s a 50-50 chance of keeping warming to below this range.

We also find a 66% probability that temperature rise can be kept below 2.9-3.4C, and a 90% probability that it stays below 3.5-4.2C.

This is an improvement on not having INDCs at all. With climate policies as they are around the world, there’s a 50% likelihood that warming would stay below 3.1-3.4C by 2100.

But the bottom line is that the level of climate action in the INDCs do not keep global temperature rise below 2C. And they present an almost 10% risk that temperature rise hits 4C by 2100.

Acceleration of action

The other possibility is to assume an acceleration in post-2030 emissions cuts.

However, here we hit a problem. Our analysis suggests that by 2030, the INDCs as they stand may have used up the entire carbon budget for a good chance – 66% probability – of keeping temperature rise below 2C this century.

This means, even if countries submit more ambitious emissions cuts in their future NDCs, we will have likely already blown the budget for 2C – and will have definitely blown it for staying below 1.5C.

Looking at emissions pathways that are in keeping with INDCs, those that come close to keeping temperature rise to 2C by 2100 depend on a rapid decline of CO2 emissions from energy and industry after 2030. This would require, for example, emissions cuts of 3.5% per year between 2030 and 2050.

Historically, some countries have managed to achieve annual emissions cuts of 2-3%, but for energy security reasons rather than to tackle climate change. Although these historical rates are not a perfect comparison, achieving this level of action at a global scale in future will be a tough nut to crack.

Therefore, if INDCs stay as they are, the likely option will be that we overshoot 2C or 1.5C, and then attempt to bring temperature back below those levels by 2100.

This option assumes a massive scale-up of negative emissions technologies, which remove CO2 from the atmosphere and store it on land, underground or in the oceans.

Our analysis suggests that the annual rate of negative emissions scale-up to the middle of the century will need to be roughly similar to the current expansion of renewable energy.

But renewable energy infrastructure is expanding because costs have reduced dramatically over the past decade and governments are starting to appreciate the benefits of a diversified and clean energy system. By comparison, the equivalent can’t be said for the roll-out of negative emissions technology around the world, or, in some cases, even the demonstration of it to work at scale.

It is premature, then, to conclude that large-scale take up of the negative emissions in the near future is achievable. And without a clear, strong, and stable long-term policy signal that makes emitting CO2 economically and politically unattractive, it thus seems very unlikely that such scale up of negative emissions technologies will ever occur.

That said, no matter what we assume post-2030, the INDCs aren’t quite enough to bring us in line with the Paris Agreement’s climate goal of keeping warming to well below 2C, let alone keeping it to 1.5C.

More needs to be done

The main conclusion of our study is, therefore, that more needs to be done before 2030, rather than waiting until later. There’s no silver bullet, but we identify the most promising ways to increase action before 2030.

One option is to expand the scope of the INDCs to include more sectors – such asinternational shipping and aviation – and other types of greenhouse gases. However, the bulk of the necessary reductions can only be achieved by extending emissions cuts in sectors already covered by INDCs, such as energy, transport and farming.

These INDCs thus need to be strengthened internationally or governments should aim to overachieve them domestically.

It is now up to governments to live up to the ambition of the Paris Agreement and make sure that increasingly ambitious emissions cuts are put forward. And this ambition needs to start before the Paris Agreement is even ratified.

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Comments 1 to 15:

  1. The "Paris Agreement" looks very good on paper, but it means nearly nothing since it's no more than a declaration of intent. It doesn't spell out any plan to actually achieve its goals of reducing CO2 emissions.

    Since the "agreement" was reached, there has been nearly no progress on the ground. I would argue that in the past few years there have been some major steps backwards, in particular the buring of "biomass" which is basically wood chips that are about as dirty as coal. The latter gets very little notice, even though at this time Germany is producing about 1/3 of its "green energy" by burning wood.

    I am not an AGW deniers, so for those of you who haven't dismissed me as a mental case, I'd like to refer you to this article. Please take a few minutes to read it so you know what I'm talking about:

    Pulp Fiction: The European Accounting Error That's Warming the Planet

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    Moderator Response:

    [PS] Fixed link. Please use the link tool in the editor to do this yourself.

  2. Paraquat@1,

    Burning coal digs up carbon that had been locked out of the recycling environment of our planet and adds it into that environment as excess CO2.

    Burning biomass also produces CO2. But it is carbon that is already in the recycling/living environment. So wood burning is better than coal burning, especially if an amount of wood is being regrown that matches the amount being burned.

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  3. To complete my point@2:

    Selective harvesting of mature trees that would naturally be near to their days of decomposing would be the best way of harvesting trees for burning. Those trees are nearly done taking in carbon, and close to decomposing creating CO2.

    That is where the trouble-making current day priority on maximizing short-term profit for the benefit of a portion of the global population gets in the way.

    The real problem is not burning wood. The real problem is the way the burning of wood develops in a socio-economic system that misguidedly prioritizes profit and popular desires (and the freedom of people to do as they please) rather than focusing effort on actions that will genuinely advance humanity to a lasting better future.

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  4. Hello One Planet Only Forever,

    I understand your point, but you've got to consider something called EROEI (energy returned on energy invested), also known as EROI (energy return on investment). You probably already know what that is since the name is self-explanatory, but anyway, it means you need to expend some energy to get energy. An EROI of 1:1 is useless since you're expending as much energy as you produce, a net gain of zero. If EROI is negative, it's worse than useless.

    A lot of green technologies looks worse when you consider EROI, but for the moment let's just consider biofuels. In the case of burning wood, Germany's greens prefer not to include the energy expended in harvesting the wood (usually in North Carolina), processing it into pellets and shipping it across the ocean to Germany. That energy is almost entirely fossil-fuel based. Furthermore, you should add in the loss of CO2 absorbing ability of a forest that is taken out of production for 20 years or so until it grows back. And then there is the loss of topsoil due to erosion, which is hard to calculate.

    It's even worse with ethanol, another biofuel that - among other sins - reduces the gas mileage of vehicles that burn it, which worsens its already poor EROI.

    I could say some bad things about other "solutions" like natural gas, and even solar and wind have some serious issues. But I don't like to lump too many topics into one, so I'll save that for another post.



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  5. @paraquat #4: Most EROEI are determined via a lifecycle analysis LCA, taking into account all emissions during the production. If one wants governement support this EROEI should be estimated with a LCA and must be positive. 

    For solid wood fuels the carbon footprint for pellets produced in a Vietnam from a mix of (all FSC approved, sustainable sources) sawdust, wood working residues and energy crop (actually materials used for paper&pulp but with the lower demand for paper now available for other uses), dried with fuels like bark, electricity generated from wood and agri-residues can have a footprint of less than 18 g/MJ and an EROEI of 7.5:1; Slightly better if one does produce bio-coal: EROEI 8.4:1 and a footprint of 14 g/MJ --Own calculations, checked with DECC calculator and according to the OpenLCA, using default provided data--.

    It does matter how the bio-coal/wood pellet is used: in a grate stoked boiler the amount of emissions is tripple the value per kWh delivered than used in a gasgenerator by gasifying and water shift+ CO2 capturing installation. 

    Germany is not importing that much wood from the USA, it's a German company owning plants in England, Netherlands and Belgium (and a pellet plant in the USA) which take the bulk of the pellets from USA & Canada. England (Drax) takes  3 million tpa, Netherlands (till 2020) 1.4 million tons and Belgium a 2.2 million tons from USA& Canada. East European countries, Portugal, Germany,Austria, Sweden do have large areals of wood, good for a 10 million tons a year, mainly for household and small boiler use. 

    Corn ethanol has EROEI 1.3:1, cellulosic ethanol EROEI of 2.2:1 and would be much better if the lignin was reused seriously in a high efficiency power train instead of using medium pressure steam generators. 

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  6. "This option assumes a massive scale-up of negative emissions technologies, which remove CO2 from the atmosphere and store it on land, underground or in the oceans."

    Most viable CO2 techniques take the CO2 out of burnable gas and store it. pump it to secondary users (for use in greenhouses: riping tomatoes takes lot of CO2). Taking out of the air is a methodology best left to trees to do and a well proven technology.  

    CO2 can be converted through CH4 and CH3OH (methanol) through the Sabatier reaction (Power to Gas storage method). Also a well known reaction. Both Methane and methanol are in use as feedstock for plastics. If the source is non-fossil, plastics serve as a very long storage option of carbon. 

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  7. Hi there Paraquat,

    I did not miss EROEI. And I intentionally separated my comments.

    The Need is: The termination of the creation of new/excess CO2 from burning fossil fuels (including natural gas). A reduction of burning of fossil fuels is not a solution. Therefore, EROEI is really only relevant for comparing energy systems that do not in any way involve the burning of fossil fuels. The least efficient system that does not add carbon to the recycling environment of this planet would be superior to any other system that involves any burning of fossil fuels. But the current fatally flawed socio-economic systems (including communism) fail to evaluate and promote things that way.

    Carbon sequestration methods matched to the burning of fossil fuels to theoretically fully neutralize the added/excess CO2 are also not a solution. There are serious questions about the certainty that the sequestered CO2 is truly permanently locked out of the recycling environment.

    Also, all indications are that carbon sequestration will be required in addition to, and for a period of time after, the termination of fossil fuel burning (admittedly only required by people who care about advancing humanity to a lasting better future - but that is the socio/political/economic aspect of the issue).

    Since it is essential that humanity advance to a lasting better future for all (that is the only viable future for humanity), any evaluation for comparison of preferred ways to do things must be restricted to only those things that are certain to be part of a lasting better future for all of humanity on this, or any other, amazing planet. So it should be clear what needs to change quickly, and it isn't the climate.

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  8. paraquat @ 1 and 4.

    Personally I'm not much  of a fan of biofuels, because of the obvious criticisms levelled against them, which I have no need to repeat here. If we are going to combat climate change, this really needs a profound change to electric vehicles. In my view biofuels only have some merit for air travel, as this is something very hard to electrify.

    However you make the point that you are not a "climate denier" then go on to say you are critical of all green technologies. This leaves me wondering.

    Exactly what is it you propose to tackle climate change?

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  9. Good comments and responses on this thread...I'm always glad to see that. I've got a lot more things to say, but today I have to cut it short because of a lot of volunteer work. I think I mentioned once before that I live in Taiwan (if I didn't, I may be confusing what I said on this blog with another blog). Anyway, last weekend we got hit by Super-Typhoon Nepartak, lots of damage in my town (Taitung, the worst hit in Taiwan). Go to Google images and type "Typhoon Nepartak Taitung" and you'll see what we're dealing with right now.

    The interesting question is whether or not Typhoon Nepartak was enhanced by AGW? And are we going to be seeing even worse typhoons in the future thanks to AGW? I'll leave that as my thought for the day. Now, time for me to gas up the chainsaw - lots of downed trees to remove from my niece's school.



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  10. nigelj@8,
    A proper and thorough comparison (competition) of the efficiency and impacts of truly sustainable energy systems would probably result in very limited use of biofuels. And truly sustainable means energy systems that future generations of humanity will be able to be benefit from until this amazing planet would naturally become uninhabitable due to the changes of the Sun, which would exclude more than just fossil fuel burning.

    It is obvious that significantly reduced resource consumption and impacts by the “choices” of the most fortunate is the primary change that is required, the quicker the better (even if that change is contrary to the desires of those who have developed perceptions of wealth, power and prosperity that cannot be justified when evaluated based on the best understanding of what is required to advance humanity to a lasting better future for all).

    Clearly, the current socio/economic/political systems fail to perform that type of evaluation (competition), primarily because of the ability of deliberate misleading marketing to influence significant numbers of people into desiring personal interests that can be understood to be detrimental to others, particularly to the detriment of future generations. The 1987 UN Report "Our Common Future", particularly highlights the damaging development results of the lack of power of future generations to limit the behaviour of their predecessors.

    To be clear, the Free Market or Capitalism or Communism are not the problem. The problem is the ability of people to get away with pursuits that can be understood to not be part of the advancement of humanity to a lasting better future for a robust diversity of life on this planet.

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  11. One Planet @10

    I broadly agree.

    In my view capitalism is generally a good system, and is just decentralised decision making and ownership. Hayek made the argument well enough.

    However capitalism has certain "market failures" that are recognised by economists, especially in environmental areas. Capitalism in its raw form generates some problems. You have essentially listed these in your post.

    The normal resolution of the problems of capitalism is for the state to fill the gap or regulate certain market behaviours to ensure the public good. Unfortuntaly some people are so self centred they resent this.

    Capitalism also has an internal feature that needs to be well understood. While the value of capitalism is in decentralised decision making and competition, the essential dynamic is towards monopolies, until there exists the possibility of something as big and unweildy as "communism"! The only way to stop this is an interventionist state, that stops monopolies forming, or which regulates monopolies. Its in the "enlightened self interest" of the publc to promote this, so there is no contradiction between capitalism and people promoting this, as self interest is a feature of capitalism.

    The point is ultimately it becomes hard to separate the state from capitalism, as they need each other to function. This is the most important thing we have to face.

    Therefore we have an argument that should not be about capitalism "versus" the state or socialism (or whatever) but which should be about how we strike the right balance and what the state should do in various regards and ultimately this has to be based on evidence and logic, not heated emotive arguments.

    Obviously this applies very much to climate change. The state has an inherent right to ensure we dont destroy the planet. Because without the planet capitalism has no future anyway.

    The cultural and ideological balance has possibly tilted too far towards "greed is good" and community values are bad. Any functional group of humans needs a blend of individual rights and community controls over some individual rights. Its a tough one, but I think western society has done ok, and we sometimes fight over absurdities. Obviously we also have to constantly ensure the balance is appropriate, and rules make sense.

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  12. nigelj,

    I agree that we substantially agree.

    One minor difference is that my position is that any pursuit that the constantly improved understanding of what is going on would identify as 'damaging' or 'unable to be a lasting part of a better future for all of humanity' is Not an Option.

    You seem to imply that pursuits that can be understood to be damaging or can be understood to only benefit a portion of humanity (especially pursuits that can only provide a benefit for a limited duration), deserve to be allowed as part of the compromise of all interests (the Balance concept).

    I disagree that people wishing to benefit from understandably damaging or unsustainable pursuits deserve to have their desires allowed to a 'balanced' degree. Those activities and pursuits need to be curtailed regardless of popular desire or profitability.

    And, of course, the burning of fossil fuels is understood to be both damaging and unsustainable.

    So, I also disagree regarding how well Western Society has done. The unacceptability of benefiting from burning fossil fuels has been clearly understood by Western Society leaders since the 1980s (and earlier). Western society has failed misearbly due to the popularity of leaders who encourage selfish interests (greed and intolerance) to drum up support.

    And it isn't just the leaders who are to blame. Any already more fortunate person wanting to get more benefit from the burning of fossil fuels deserves to be disappointed, not rewarded. Western Society has significantly failed to do that.

    But Western Society has been great at developing excuses to prolong and expand what is understood to be unacceptable. It has been great at fighting against changes to limit what can be gotten away with rather than working to limit the magnitude and rate of change of the climate.

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  13. One Planet @ 12

    No. Im not saying that. By "balanced" I simply meant that in general terms a workable economic system has to recognise balance between individual rights and the restrictions of the law in general terms, and not let it become skewed too much one way or the other. Its just a philosophical point that society works with a balance of individual and community rights, and extreme libertarian systems dont really work, just as communism doesn't work at the other extreme. I was trying to show that capitalism is perfectly compatible with a degree of government involvement in regulating market behaviour and these things complement each other.

    Certainly in some cases individual behaviour that is damaging must be totally curtailed. Pollution is a case in point.

    As I pointed out market behavious that are potentially damaging should be regulated by the state, or eliminated (depending on the specific behaviour, for example pollution should be eliminated, and punished, driving cars is regulated with road rules).

    Even economists recognise this, even those that lean to the right politically, in the main. Its politicians and lobby groups etc that argue that governments should have strictly limited powers and corporate interests should be paramount and regulation eliminated or reduced to an extremely low level.

    Western society has generally worked with the model I have outlined that balances individual freedom and state involvement, but this has come under threat since the 1980s and swung too far towards an ideology of corporate rights and deregulation etc. This has made mitigating climate change very difficult. People use scaremongering about excessive state powers or laws as an excuse to prolong their polluting behaviour.

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  14. "the INDCs aren’t quite enough to bring us in line with the Paris Agreement’s climate goal of keeping warming to well below 2C"That's an understatement. The "quite" implies that it's close but the text of the article says that for even a 50% chance, the INDCs (and an assumed continuation of the assumed effort) are nowhere near close enough to stay below 2C. But a 50% chance is nowhere near to "keeping" warming to a target. Let's get real; a 90% chance would give us some hope that warming could be kept to a, still disastrous, 2C but the INDCs barely scratch the surface of what is needed.From a Guardian story, the elders of the UN are worried that actions are already failing the words of Paris: 'Presidents and prime ministers across the world are making investment decisions that run contrary the Paris deal, they warned. “Some countries are even increasing subsidies to fossil fuel production. This is simply not good enough. While all countries need to act, the industrialised and wealthy countries must lead by example.”'The Paris agreement is already failing.
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  15. Apologies for the poorly formatted comment - it wasn't poorly formatted in the comment box!
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