Paper out today on high-latitude low-altitude stratospheric aerosol injection (HiLLA-SAI). It's long, with literally 100s of sub-plots, so TL:DR: HiLLA-SAI is a polar-focused but still global intervention, with ~40-70% the global cooling efficiency of "normal" SAI
esd.copernicus.org/articles/17/...
On Friday, I'm talking with the head of Reflective, a nonprofit trying to accelerate the responsible research of solar radiation modification (SRM), ie, blocking some sunlight from reaching earth in order to cool the atmosphere. Geoengineering!
Got questions?
the fact it only hits a particular cohort is what gets me. I will pay much more tax than grads a couple years older than me in the same job, for my whole life!
Giving what we can has implemented a fun game where you spin a globe to see how your starting point in life would compare if you were reborn today, randomly somewhere on earth.
www.givingwhatwecan.org/birth-lottery
New paper on Marine Cloud Brightening in the Arctic!
Our simulations show that the introduction of sea-salt aerosols brightens clouds in the Arctic and leads to substantial Arctic cooling, which also restores Arctic sea ice.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
Excerpt from the book The Planet Remade stating that Germany is the country that has been spending the most money in solar geoengineering research
Reading back through @eaterofsun.bsky.social 's The Planet Remade and thought this snippet about German involvement in geoengineering research was interesting. 10 years later the opposite seems true.
On the other hand, the description of GeoMIP conferences fits the recent ones pretty well..
This from @outrageoptimism.bsky.social is a great intro to recent solar geoengineering developments
www.outrageandoptimism.org/episodes/jac...
Our paper is published! 🎉🎉🎉
If you want to understand changes in total rainfall under warming, give this a read!
Happy to chat about it with people :)
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
In 2022, archaeologists at @uni-kiel.de's @neolithicbodies.bsky.social found 34 decapitated skeletons piled in a space the size of a parking spot. In the 3 years since, they’ve found 50 more. The mass grave is evidence for the collapse of the 1st pan-European culture 7,000 years ago. @science.org 🏺💀
Why too low?
Those homes aren't 'mansions' by most standards. But if you own a 1.5M home in central London you either bought it recently and therefore have money, or benefitted from big unearned housing market gains and could share some of that back with the state?
@aliduffey.bsky.social and I have a new response to the Siegert et al piece on geoengineering published as a commentary in Frontiers (the online version is now properly edited with the figure).
Should we start historical climate simulations in 1750 (or 1800) rather than 1850?
Importance of beginning industrial-era climate simulations in the eighteenth century
Ballinger, Schurer et al.: iopscience.iop.org/article/10.1...
In this opinion piece, two scientists argue that the growing commercial efforts to counter climate change by reflecting away sunlight will thwart responsible research in the field.
📝 Call for all Polar Researchers to take the Science under Pressure survey!
Submissions deadline is 15 November 2025
Read more and take the survey: www.rug.nl/research/arc...
Fair, but it's a step into the dark either way, and the uncertainty under [more warming] might be larger than that under [less warming + SAI]
of course, but by my back of the envelope 'eventually' here means order 100,000 years.
1°C cooling ~ 10 Tg SO2 ~ 1% of current aviation ~ 0.03 % of global CO2 emissions ~ 1E-5 °C extra warming per year SAI
Lots of good reasons not to do SAI but the CO2 impact isn't one of them
Well said Dan! After a week spent with the inspiring early career SRM community and Operaatio Arktis folks, the contrast in values to Stardust couldn't feel stronger
Did Northern Hemisphere air pollution contribute to 70s and 80s Sahel drought? We think so, but we're still arguing about how much.
For the most important risks of solar geo, consensus would (hopefully) emerge, but slowly. Informed by observed climate, but still based on theory and modelling
"when we deploy it we will see how effective is"
I hear this quite a bit but it isn't true.
10 years into a hypothetical SAI deployment, observed rainfall patterns would be pretty much useless for reducing our uncertainty in e.g. indian summer monsoon impacts
Interesting new paper from Exeter colleague Jim Haywood, and previous @exeter.ac.uk PhD student Alice Wells about geoengineering - specifically what would sulphate aerosol injection do with respect to high levels of global warming 1/2.
agupubs.onlinelibrary.wiley.com/doi/full/10....
The NYT piece quoted here is amazing. Written over 70 years ago and reads exactly like articles about this summer's Texas Rainmaker conspiracy
love this chart. It's too late for 1.5, but the fight for 2C is very much still alive
wrote about this last year and sure I wasn't in any way the only one but imo people voting for populist politics in the 21st century *is* a sign that they do just have too much faith in institutions, as opposed to not enough - they want to have their little tantrum but assume things will just hold
The evidence we have, though, suggests SAI is not like these other ideas, being instead logistically feasible, effective and quite cheap.
We could be wrong on all three of these, of course, but honest debate about geoengineering demands that we grapple with that evidence
The SAI section bends over backwards to try to fit it into the same mould as the others (logistically difficult, expensive, and ineffective), but in doing so makes some surprising errors as well as being one-sided.
But the idea that further research into these is a waste of resources is crazy to me, when i think about what is at stake here.
Yes sea-curtains sound difficult, but so does building a sea-wall around Bangladesh.
Similarly for the ice sheet interventions. While those working on these have been the first to ackowledge that they are profoundly ambitious ideas, the Siegert et al study is a valuable and welcome critical perspective to help understand how and why these ideas would face challenges.
My impression is that sea-ice thickening and the ice sheet interventions are somewhere between implausible and just unlikely. The potential for sea-ice thickening to meaningfully impact global climate is often exaggerated, though, and its good to call this out
Glass beads for sea-ice albedo modification has always been an implausible idea - here's me in 2023 writing as much. I welcomed the decision of the Arctic Ice project folks to wind down their activities.
www.arcticiceproject.org/the-project/
agupubs.onlinelibrary.wiley.com/doi/full/10....