It’s New York Climate Week! I’m on a plane today to NYC, so I want to share this with you today in lieu of posting during the middle of the week. If you are in town, come find me at one of the stabilization-related events, and check out the list of events in this post from a couple of weeks ago.
In what was pitch perfect timing, on the same day I announced changing the name of this Substack to The Overshoot Era, the United Nations Environment Programme (UNEP) released a report titled “Limiting Overshoot - Navigating exceedance of 1.5°C and pathways towards return”.
Some have asked me if I’d write about it, but to be honest, I thought a few other Substackers covered it much better than I could have, so I want to share those with you here.
First was Security Takeaways from the UNEP Overshoot Report, by Erin Sikorsky:
Erin makes the smart point here that from a security perspective (i.e. militaries) they simply must start preparing now for a reality that is seeming ever more likely:
Greater exploration of the diplomatic/security practicalities of carbon removal and solar radiation modification: I differ from the UNEP report here, which wants to keep the former as minimal as possible and dismisses the latter as unproven. I understand the political inclination – we cannot pretend there is an ‘easy’ way out of the conundrum we’ve built ourselves and give countries a free pass on mitigation. However, security actors in particular have to be realistic – these technologies are almost certain to be a part of our future, and we must prepare in such a way that ensures we maximize their utility in enhancing our security, not threatening and undermining it. We cannot wish away the conversation.
I’m currently reading Erin’s book, Climate Change on the Battlefield: International Military Responses to the Climate Crisis, and I keep thinking this stabilization field is underestimating the role of security actors in future interventions. Don’t get me wrong, discussions about the intersection of security and catastrophic climate and tipping-point risks are happening, but as Erin points out in her book, when you consider what resources countries will lean on (are already leaning on!) for massive infrastructure or disaster response, it is hard not to conclude militaries are going to play a strong role. And when I think about the future of climate interventions, it seems painfully obvious to me that this is going to be governments as customers, contracting out to private actors, in coordination with both civilian and military institutions. That’s how everything else works, so why wouldn’t it here?
The second article was from Noah Deich, who published UNEP Report Review: “Limiting Overshoot”:
Noah makes a point I very much agree with, which is that they are still not addressing the reality of what we must consider for our response options:
Now, why the report made me grumpy: despite all of these clear and useful conclusions in the report, it quickly becomes clear that the authors really want you to conclude that we have to ramp up our efforts on emissions reductions way faster than we currently are doing. In particular, they don’t want you to think that we should slow down investment in reductions today because we can instead rely more on removals in the future — and they reeeeeaaaaly don’t want you to make a similar conclusion on solar radiation management (SRM).
He goes on to point out that not talking about CDR and SRM honestly undermines the credibility of the report:
Hiding the ball on SRM and misrepresenting claims about the limits of carbon removal in a report on overshoot is an unnecessary risk to the entire report’s credibility. Why not instead just lay out the facts on carbon removal and SRM, and let policymakers come to their own conclusions about how to proceed with each?
To be clear, I agree with the UNEP’s conclusion that the focus of tackling overshoot should center on accelerating emissions reductions. But it comes across as patronizing — and reveals the report authors’ fairly bleak assessment of policymakers’ decision making ability — when they try to shape the narrative in this direction in such a heavy-handed way.
I agree strongly with this as well. There’s a very obvious elephant in the room here, which is, what happens if we don’t slam the brakes on emissions like it calls for? The report simultaneously points out that we have not begun decreasing emissions, and the attendant risks of not decreasing emissions are potentially catastrophic. But then it just leaves dangling the issue of what we should actually consider doing about that.
SRM isn’t the only thing missing, either. The report says warm-water coral reefs are crossing their thermal threshold right now at 1.4°C, that the carbon coming out of thawing permafrost may never go back in, and that the West Antarctic and Greenland ice sheets and the Atlantic circulation are among the tipping elements it expects to be at growing risk the longer warming stays above 1.5°C, and then it says that even optimistic carbon removal would bring temperatures back down by only a few tenths of a degree this century. So by its own numbers those systems are on their own for decades, and there is nothing in it about the work already underway to protect specific systems, like brightening clouds over the Great Barrier Reef, thickening Arctic sea ice, or the seabed curtain proposed for Thwaites Glacier.
Large reports like this are very difficult to put together, and they often end up being a lowest common denominator sort of affair, where only the most sanitized statements can make it through all of the veto points. But come on people, the problem is worsening quite rapidly, and we’re still not even mentioning SRM, while the CDR chapters read like a list of reasons it won’t work rather than a plan for making it work.
Lastly we have a slightly more sanguine take from Quico Toro with One Cheer for UNEP’s Limiting Overshoot Report:
Quico refers to the whole international policy apparatus as the “UN Climate Blob” because it is a slow-moving beast. That name incorporates some of what I meant by the lowest common denominator above:
Look, a blue ribbon report like this can’t, obviously, say anything interesting: co-authored by dozens of researchers in universities and government labs spread over six continents, the UN machine will make sure to squeeze out any sign of originality long before a beast like this comes anywhere near publication. Many very respectable people at eminent institutions have their fingerprints on this product, none of them want to face the blowback that would come from upsetting orthodoxies. Reports like this one exist not to be provocative, but to capture the consensus position in the UN Climate Blob. By design, Limiting Overshoot was never going to be anything other than a compendium of things very cautious people can all agree on.
But Quico is cautiously optimistic because this report represents a small step towards acknowledging the truth of where we are right now. Warming is accelerating, and holding on to 1.5 degrees is no longer feasible. A major UN agency saying as much means a lot of people who made commitments in 2015 to never let this happen are eating crow, and that’s a difficult thing to do.
Quico also points out the obvious truth that I have been shouting into the ether forever, that expensive CDR is simply not going to happen. The only way we can actually solve this problem long-term is if CDR can be done massively at scale and for very low price per tonne:
There is simply no reason to believe that a world that has failed to mobilize $800 to prevent the emission of one ton of CO₂ from a steel mill will somehow, magically, find the will to mobilize $800 to capture a ton of CO₂ via DAC. (If anything, the opposite is true: the steel-maker has a good reason to make steel —so they can sell steel!— the DAC plant has costs but no revenues.)
What a report like Limiting Overshoot was never going to do is acknowledge something that, to me at least, is fully obvious: that there’s no point in CDR if it’s going to cost as much, ton per ton, as mitigation. That gigaton-scale CDR is only ever going to be a thing if it’s an order of magnitude cheaper than the alternative.
All in all, this report is a mixed bag. It’s a very good thing that the “UN Climate Blob” is finally admitting that we’re going to blow right past 1.5, and that even in their most optimistic scenario getting back under it is a decades-long project. That’s a good first step. But it is of utmost importance that the next steps (talking seriously about SRM, about carbon removal that is cheap enough to actually scale, and about the regional interventions that could protect reefs and ice sheets and the rest while the slower solutions catch up, all alongside rapid emissions cuts) be taken with great haste. This current El Niño is going to give us a taste of what is in our very near future, and no one is going to like it. We must find ways to move faster in preparing for that future.





