Their first (and, I presume, their best; why would you put anything else first?) example is global warming of 2C is projected to reduce yields of staple crops by 5–20%. Yet greenhouse gas mitigation options can also increase food insecurity if bioenergy crops displace food crops, or can lead to biodiversity loss from land-use change and afforestation. But while GW, all by itself, might reduce yields, nonetheless yields overall are going up. And bioenergy is dumb, and it is unlikely that people will be dumb enough to do it on a large enough scale to affect global food production. So if that's the kind of top-level risk they're worried about, I personally wouldn't bother worry. Unless someone was paying me to, I suppose.
Is there more? Still on food, they suggest Similarly, trade networks link distant food systems together and can, thus, compensate for reduced food security. However, they can also create new risks of global impacts, such as multiple-breadbasket failure, more rapid spread of disease, pests and invasive species, and new threats to local food security from changes in commodity prices caused by policy choices made elsewhere. But this too is unconvincing; the converse - that trade and globalisation smooth out local production problems - is stronger. And, really, it isn't very much to do with GW anyway.
Dull stuff I think. So, I'll stop there :-). FWIW I still think that the most likely real dangerous risk of GW is on the biosphere, but in unpredicatable ways.
Refs
*There is no stark racial difference that jumps out, rather a dreary sameness - TF
* The Chauvin Verdict: A Good Start…Or Not - by Tarnell Brown at EconLog
* What has changed over humanity’s recent history is not biology, psychology, physiology, ecology, or geography. What has changed, instead, is their attitudes...
* Incentives Matter in Banking Too by David Henderson
* THE EXISTENTIAL THREATBURGER : HERE'S THE BEEF!
* No, global warming is not 50% of what CMIP6 models predict - Moyhu on Roy; Making predictions with the CMIP6 ensemble by Gavin.
* Fuckwits at Crooked Timber wanting to destroy big tech. I used to think John Quiggin was sane.
* Frédéric Bastiat’s 1850 Economic Harmonies; Chapter XXII, titled “The Driving Force of Society”.
* Assessing My COVID Expectations by Bryan Caplan
* Welcome To The Terrible World Of Prescription-Only Apps - SSC / AST