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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.

ghg-emissions-201612-nature-climate-paper

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?