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GHG Emissions: 2C Pathways Are A Fantasy

A new commentary piece in Nature Climate Change continues to make significant errors and propagates a mistaken core assumption too many in the climate community make: that with enough [insert: political will or technological breakthroughs], 2C warming is still an achievable goal.

I have disagreed with this assumption and therefore its conclusion for six years – ever since establishment Democrats decided to waste valuable political capital on a right-wing insurance bill with a vague promise that climate legislation would come someday.  That decision essentially assured that, absent a global economic collapse or catastrophic geologic events, our species would easily push the planet past 2C warming.

The following graphic shows global historical emissions in solid black.  The green curve represents the fantasy projection of an emissions pathway that leads to <2C global warming.  As you can see, emissions have to start declining this year in the assumed scenario.  The yellow curve represents what is likely to happen if climate action is delayed for 8 years and this year’s emissions remain constant during those 8 years.  It gets increasingly difficult to achieve the same long-term warming cap because of that 8 year delay.

The red curve builds on the yellow curve projection by keeping the next 8 year’s emissions constant but reducing federal money to research decarbonization technology.  This is the linchpin to any emissions pathway that could potentially put us on a pathway to a less warm climate.  Decarbonization technology has to not only be fully researched but fully deployed on a planetary scale for the 2C pathway to happen.  It’s hard to see on this graph, but global emissions have to go net negative for us to achieve <2C warming.  While the yellow curve has a harder time achieving that than the green curve, the red curve doesn’t get there one century from now.  But the red curve isn’t the most likely pathway – it wasn’t in 2010 and it isn’t today.

The most likely pathway is the solid black curve out to 2125.  It assumes the same things as the red curve and adds an important component of reality: emissions are likely to increase in the near-term due to continued increased fossil fuel use.  Natural gas and coal plants continue to be built – any assumption otherwise might be interesting academically but has no place in the real world.  By assuming otherwise, scientists make themselves a target of future policy makers because the latter won’t pay attention to the nuanced arguments the scientists will make once it’s clear we’re hurtling past 2C.  Once we burn increasing amounts of fossil fuels during the next 8 years (as we did the 8 years before that and so on), it is harder still to cut emissions fast enough to try to keep global warming <2C.  The reasons should be obvious: the emitted GHGs will radiatively warm the planet so long as they’re in the atmosphere and it will take even more technological breakthroughs to achieve the level of carbon removal necessary to keep warming below some level.


The authors recognize this challenge:

[…]to remain within a carbon budget for 2 °C in the baseline scenario considered, peak reduction rates of CO2 emissions around 2.4% per year are needed starting mitigation now. A global delay of mitigation action of eight years increases that to 4.2% per year (black dashed in Fig. 1a) — extremely challenging both economically and technically. The only alternative would be an overshoot in temperature and negative emissions thereafter. Research in negative emissions should therefore be a priority, but near term policy should work under the assumption that such technology would not be available at large scale and low cost soon.

I disagree with the author’s conclusion:

Society is at a crossroad, and the decisions made in the US and elsewhere over the next 4–8 years may well determine if it is possible to limit climate change to levels agreed in Paris.

We passed the crossroad already.  It really doesn’t matter when, the fact is we passed it.  I think it is a waste of time to examine low-end emission scenarios for policy purposes.  They serve some scientific use.  Policy makers need relevant scientific advice and 2C scenarios don’t do that.  They perpetuate a myth and therefore pose a real danger to society.  The so-called reality-based community needs to critically self-examine what they’re doing and why they’re doing it.  We’re headed for >3C warming and we need to come to terms with what that means.

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Commercialized Carbon Removal

The Guardian has an interesting article about startups working on capturing carbon dioxide from the air – a necessary technology if we are serious about any kind of climate goal with less CO2 than our business-as-usual pathway.  What are the companies doing and why is it important?  The article highlights three businesses: Carbon Engineering, Global Thermostat and Climeworks, which started in the 2000’s.  “All are aiming to make low-carbon fuels, used recycled CO2 and renewable energy to power the process.”  They’re making low-carbon fuels because small markets for them already exist.  Those markets will have to increase in size and scope for these startups to grow.

That’s one important aspect.  Another is the so-called “climate goal”.  As stated by international groups and increasing numbers of scientists, the climate goal is keeping CO2 concentrations below a certain threshold in order to keep global temperatures from increasing above 2C.  There is another international climate conference scheduled for later this year – the Conference of Parties in Paris, France (COP-21).  Leading up to that conference, countries are submitting carbon reduction goals that can be internationally monitored and verified.  Goals stated so far will definitely not meet the <2C goal – read about the UK’s goals here, for example, or here about the 45 countries who submitted plans already.  The reason is simple: we cannot deploy enough renewable energy generation or institute enough efficiency measures or change fuel types fast enough that will translate into halving global CO2 emissions within 10 years and going net negative by 2050.

What these companies are doing is directly related to that last goal: net negative CO2 emissions.  It won’t happen by 2050 or any other year unless we push serious money into research, development, and deployment.  It will take the private and public sectors working together for decades for utility-scale CO2 withdrawal from fuel burning and the free atmosphere.  These companies, and others, are the forefront of that industry.  But they need capital – a lot of it.  Cashflow at this juncture of their existence is crucial for them to exist long enough to deploy their technologies and evolve them as they run in the real world.  Anyone have a spare million or so dollars sitting around?


What About That 2 °C Warming Goal?

David G. Victor and Charles F. Kennel, who are researchers in International Relations and Oceanography, respectively, wrote a Comment article for Nature at the beginning of October.  In it, they argued that climate and policy folks should stop using 2 °C as the exclusive goal in international climate policy discussions.  I agree with them on principle, but after reading their paper and numerous rebuttals to it, I also agree with their reasoning.

I’ll start with what they actually said because surprise, surprise, tribal and proxy arguments against their commentary focused on very narrow interpretations.

Bold simplicity must now face reality. Politically and scientifically, the 2 °C goal is wrong-headed. Politically, it has allowed some governments to pretend that they are taking serious action to mitigate global warming, when in reality they have achieved almost nothing. Scientifically, there are better ways to measure the stress that humans are placing on the climate system than the growth of average global surface temperature — which has stalled since 1998 and is poorly coupled to entities that governments and companies can control directly.

I agree with their political analysis.  What have governments – including the US – done to achieve the 2 °C goal?  Germany for instance largely switched to biomass to reduce GHG emissions while claiming that renewables (read: solar and wind) are replacing fossil fuels.  The US established more robust vehicle emissions and efficiency requirements, but the majority of US emission reductions in recent years result from cheap natural gas and the Great Recession.  No country will meet its Kyoto Protocol emissions goal – hence the hand-wringing in advance of the Paris 2015 climate conference.  And by the way, even if countries were meeting Kyoto goals, the goals would not lead to < 2 °C warming.

More from the authors:

There was little scientific basis for the 2 °C figure that was adopted, but it offered a simple focal point and was familiar from earlier discussions, including those by the IPCC, EU and Group of 8 (G8) industrial countries. At the time, the 2 °C goal sounded bold and perhaps feasible.

To be sure, models show that it is just possible to make deep planet-wide cuts in emissions to meet the goal. But those simulations make heroic assumptions — such as almost immediate global cooperation and widespread availability of technologies such as bioenergy carbon capture and storage methods that do not exist even in scale demonstration.

We will not achieve either of the last two requirements.  So we will very likely not achieve <2 °C warming, a politically, not scientifically, established goal.

A single index of climate-change risk would be wonderful. Such a thing, however, cannot exist. Instead, a set of indicators is needed to gauge the varied stresses that humans are placing on the climate system and their possible impacts. Doctors call their basket of health indices vital signs. The same approach is needed for the climate.

Policy-makers should also track ocean heat content and high-latitude temperature. […]

What is ultimately needed is a volatility index that measures the evolving risk from extreme events — so that global vital signs can be coupled to local information on what people care most about. A good start would be to track the total area during the year in which conditions stray by three standard deviations from the local and seasonal mean.

So the authors propose tracking a set of indicators including GHG concentrations, ocean heat content, and high-latitude temperature.  What is most needed? An index that measures evolving risk from extreme events.  That’s pretty cut and dry reading to me.

Of course, climate scientist activists took umbrage that somebody left their tribe and tried to argue for something other than a political goal that they didn’t have any input on that, by the way, we won’t meet anyway.

RealClimate (RC) starts by attacking the authors personally for not describing why the recent surface global warming pause isn’t really a pause – which is a tangential discussion.  RC also writes that “the best estimate of the annual cost of limiting warming to 2 °C is 0.06 % of global GDP”.  Really?  The “best” according to whom and under what set of assumptions?  These aren’t details RC shares, of course.  Cost estimates are increasing in number and accuracy, but this claim also misses the fundamental point the authors made: “technologies such as bioenergy carbon capture and storage methods that do not exist even in scale demonstration”.  RC confuses theoretical calculations of economic cost with the real-world deployment of new technologies.   To achieve the 2 °C goal requires net removal of CO2 from the atmosphere.  That means we need to deploy technologies that can remove more CO2 than the entire globe emits every year.  Those technologies do not exist today.  Period.  IF they were available, they would cost a fraction of global annual GDP.  It’s the IF in that sentence that too many critics willfully ignore.

RC then takes the predictable step toward a more stringent goal: 1.5 °C.  Wow.  Please see the previous paragraph to realize why this won’t happen.

RC also dismisses the authors’ claim that the 2 °C guardrail was “uncritically adopted”.  RC counters this wildness by claiming a group came up with the goal in 1995 before being adopted by Germany and the EU in 2005 and the IPCC in 2009.  Um, what critical arguments happened in between those dates?  RC provides no evidence for its own claim.  Was the threshold debated?  If so, when, where, and how?  What happened during the debates?  What were the alternative thresholds and why were they not accepted?  What was it about the 2 °C threshold that other thresholds could not or did not achieve in debates?  We know it wasn’t the technological and political features that demanded we choose 2 °C.  Diplomats and politicians don’t know the scientific details between IPCC emission scenarios or why 2 °C is noteworthy other than a couple of generic statements that a couple of climate-related feedbacks might start near 2 °C.  Absent that scientific expertise, politicians were happy to accept a number from the scientific community and 2 °C was one of the few numbers available to use.  Once chosen, other goals have to pass a higher hurdle than the status quo choice, which faced no similar scrutiny.

RC then rebuts the authors’ proposed long-term goal for a robust extreme events index, claiming that such an index would be more volatile than global temperature.  The basis for such an index, like any, is its utility.  People don’t pay much attention to annual global temperatures because it’s a remote metric.  Who experienced an annual mean global temperature?  Nobody.  We all experienced local temperature variability and psychological research details how those experiences feed directly into a person’s perception of the threat of climate change.  Nothing will change those psychological effects.  So the proposed index, at least in my mind, seeks to leverage them instead of dismissing them.  Will people in Miami experience different climate-related threats at a different magnitude than mid-Westerners or Pacific Islanders?  Of course they will.  2 °C is insufficient because the effects of that threshold will impact different areas differently.  It’s about a useful a threshold as the poverty level or median wage.  Those levels mean very different things in rural areas compared to urban areas due to a long list of factors.  That’s where scientific research can step in and actually help develop a robust index, something that RC dismissed at first read – a very uncritical, knee-jerk response.

Also unsurprisingly, ClimateProgress (CP) immediately attacks the authors’ legitimacy.  It’s telling that the same people who decry such tactics from the right-wing so often employ them in their own discourse with people who are trying to achieve similar goals.  CP also spends time hand waving about theoretical economic analyses while ignoring the basic simple real-world fact that technologies don’t exist today that do what the IPCC assumes they will do starting tomorrow on a global scale.  It’s an inherent and incorrect assumption which invalidates any results based on it.  I can cite lots of theoretical economic analyses in any number of discussions, but the theory has to be implemented in the real world to have any practical meaning.  I want carbon capture technologies deployed globally tomorrow too because I know how risky climate change is.  Wishing doesn’t make it so.  It’s why I’ve been critical of the Obama administration for putting all of their political capital into a plan to drive millions of US consumers into for-profit insurance markets instead of addressing the multitude of problems facing the country, including the desperate need to perform research and development on technologies to help alleviate future climate change.

The authors responded to RC and CP in a DotEarth piece.  I agree with this statement:

The reality is that MOST of the debate about goals should centrally involve the social sciences—more on that below.

What I find interesting about this statement is that if we were to follow RC’s and CP’s heavy-handed criticism, they shouldn’t have a seat at the climate goal-setting table because they don’t have the requisite expertise to participate.  What social science credibility do physical scientists have?  Too many activists like those at RC and CP don’t want anyone else to have a seat at the table, but have they staked out a legitimate claim why they get one while nobody else does?  They continue a little later on:

This is where a little bit of political science is helpful. I can’t think of any complex regulatory function that is performed according to single indicators. Central bankers don’t behave this way when they set (unilaterally and in coordination) interest rates and make other interventions in the economy. Trade policy isn’t organized this way. In our article we use the example of the Millennium Development Goals because that example is perhaps closest to what the UN-oriented policy communities know—again, multiple goals, many indicators. That’s exactly what’s needed on climate.

They also note that different perspectives leads to different types of goals – which directly contradicts the climate community’s acceptance of 2 °C as the only goal to pursue.  They push back against their critics’ denouncement for not including enough about how people set the 2 °C threshold:

The reason it is important to get this story right is not so that the right community gets “credit” for focusing on 2 degrees but so that we can understand how the scientific community has allowed itself to get lulled into thinking that it is contributing to serious goal-setting when, in fact, we have actually not done our jobs properly.

They identify what I think is the real critical issue which people bury with the proxy battles I present above:

That means that for nearly everyone, the question of goals is deeply intertwined with ultimate impacts, adaptability and costs.  Very quickly we can see that matter of goal-setting isn’t some abstract number that is a guardrail but it is bound up in our assessments of risk and of willingness to pay for abatement as well as bear risk.

The point here is perhaps most salient: the 2 °C threshold is but one value in a very large set.  Different people have different goals for different reasons – based on their value system.  As well they should.  The 2 °C threshold is treated as a sacred cow by too many in the climate community.  What happens when, as I now believe will happen, the globe warms more than 2 °C?  Will folks finally stop cherry picking statistics and brow-beating other folks who are really their allies in this effort?  Will folks set aside tribalism and accept expertise from other researchers, you know, acceptance of other sciences?

There are many more pieces written about this Nature Comment that I didn’t get into here.  They all serve as interesting exhibits in the ongoing effort to get our heads around the wicked problem of climate change and design efficient policies to change our emissions habits.  This unfortunately won’t be the final example of such exhibits.