Thread by @RogerPielkeJr

Another interesting critique of IPCC scenarios finds carbon capture growth rates too high in 1.5/2deg scenarios, but also that CCS remains a huge challenge

Global geologic carbon storage requirements of climate change mitigation scenarios
pubs.rsc.org/en/content/art…

Climate scientist reactions to this paper compiled by @SMC_London are remarkably political:
1-“potential of CCS should not be seen as a reason not to cut carbon emissions now”
2-“it is still not a silver bullet”
3-“radical mitigation though is fundamental”
sciencemediacentre.org/expert-reactio…

These reactions offer a great example of the use of scenarios to demarcate boundaries between what policies scientists view as acceptable & which are not

When scenarios break down (eg, vs real world) these boundaries get challenged & reinforcement occurs

issues.org/opening-up-the…

1-Large-scale carbon capture necessary in climate scenarios for deep decarb targets
2-But scenario assumptions are so aggressive it is practically impossible
3-That means we must rely on “radical mitigation” instead
4-More feasible CCS would call into question 3
5-So 4 is bad

Put another way
Impossible CCS assumptions in IPCC scenarios are not to be taken seriously
They show deep decarb is posssible
But we can’t get there via CCS
Impossible scenarios reinforce a particular approach to mitigation
But some people didn’t get the memo & take seriously CCS

And this, my Twitter friends, offers a wonderful case in how scenarios are deeply political & can be used stealthily to (dis)favor certain policy approaches
Unless you are looking carefully, you might not see what is right in front of your eyes
And that’s why we study STS!
/END