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Ali Duffey

@aliduffey.bsky.social
297 followers 768 following 105 posts

Climate science | Stratospheric aerosol injection | Arctic climate change Senior Scientist at Reflective and visiting researcher at UCL

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Reposted by Ali Duffey
Oliver Morton, Eater of Sun @eaterofsun.bsky.social · 25/09/2026
Really helpful climate graphic—can't remember seeing a plot quite like this before. www.theclimatebrink.com/p/my-new-nyt...
Chart showing cumulative probabilities of passing various levels of warming (y axis) over time (x axis) on the basis of current policies. The curve for 2 degrees is sigmoid, reaching 50% at 2050 and saturating at 100% by 2100. The curve for 3 degrees lifts off zero just before 2050 and reaches 50% in 2107. By 2150 (end of the chart) it has reached 77%. 4C gets started around 2075, is <5% at 2100 and has reached 28% by 2150
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Ali Duffey @aliduffey.bsky.social · 26/08/2026
To some extent we just have to be able to walk and chew gum at the same time though. If you want SRM to be on the table in 15-20 years with a full(ish) understanding of the risks (+how to actually do it in practice), that means scaling up the research program today - science is slow!
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Ali Duffey @aliduffey.bsky.social · 13/08/2026
Faster Route!
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Reposted by Ali Duffey
Dan Visioni @danvisioni.bsky.social · 19/06/2026
“Nobody has ever studied this carefully” said the people who spent 10 years threatening to tank the carrier of anybody daring to studying that thing carefully and systematically. I’m going to have a brain aneurysm before 40.
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Ali Duffey @aliduffey.bsky.social · 20/06/2026
I guess they meant 1C to 3C?
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Ali Duffey @aliduffey.bsky.social · 16/04/2026
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/...
esd.copernicus.org
The global climate response to High-Latitude Low-Altitude Stratospheric Aerosol Injection (HiLLA-SAI)
Abstract. High-latitude low-altitude (HiLLA) Stratospheric Aerosol Injection (SAI) would face fewer logistical barriers than high-altitude low-latitude SAI, because it could use repurposed existing la...
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Reposted by Ali Duffey
David Roberts @volts.wtf · 04/03/2026
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?
reflective.org
Reflective | Radically Accelerating the Pace of Sunlight Reflection Research
We equip the world with the data and tools needed to make informed decisions about sunlight reflection, fast enough to matter.
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Ali Duffey @aliduffey.bsky.social · 20/01/2026
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!
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Julia M. Rohrer @dingdingpeng.the100.ci · 25/12/2025
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
givingwhatwecan.org
Birth Lottery
If you were reborn today, where would you land? And how would that change your life?
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Matthew Henry @mattjohenry.bsky.social · 11/12/2025
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/...
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Ali Duffey @aliduffey.bsky.social · 07/12/2025
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..
Excerpt from the book The Planet Remade stating that Germany is the country that has been spending the most money in solar geoengineering research
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Ali Duffey @aliduffey.bsky.social · 05/12/2025
This from @outrageoptimism.bsky.social is a great intro to recent solar geoengineering developments www.outrageandoptimism.org/episodes/jac...
outrageandoptimism.org
Jacinda Ardern and… Is It Time to Talk About Geoengineering?
This week, hosts Tom Rivett Carnac and Paul Dickinson delve into the rapidly emerging - and faintly surreal - world of solar geoengineering.
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Reposted by Ali Duffey
Andrew Williams @andrewilwilliams.bsky.social · 04/12/2025
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/...
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Andrew Curry @andrewcurry.com · 20/11/2025
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 🏺💀
science.org
Headless bodies hint at why Europe’s first farmers vanished
Wave of mass brutality accompanied the collapse of the first pan-European culture
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Ali Duffey @aliduffey.bsky.social · 21/11/2025
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?
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Reposted by Ali Duffey
Matthew Henry @mattjohenry.bsky.social · 14/11/2025
@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).
frontiersin.org
Frontiers | Commentary: Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects
Research into polar climate intervention is understandably controversial. The deliberate manipulation of Earth's climate has deep physical, political, an...
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Ed Hawkins @edhawkins.org · 06/11/2025
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...
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Reposted by Ali Duffey
MIT Technology Review @technologyreview.com · 04/11/2025
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.
technologyreview.com
Why the for-profit race into solar geoengineering is bad for science and public trust
Two scientists argue that the growing commercial efforts to counter climate change by reflecting away sunlight will thwart responsible research in the field.
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Reposted by Ali Duffey
IASC_Arctic @iasc-arctic.bsky.social · 31/10/2025
📝 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...
rug.nl
Science under Pressure
Science under pressure: Reflecting on conditions, practices and institutional structures for sustainable polar research
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Ali Duffey @aliduffey.bsky.social · 30/10/2025
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]
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Ali Duffey @aliduffey.bsky.social · 27/10/2025
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
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Ali Duffey @aliduffey.bsky.social · 25/10/2025
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
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Ali Duffey @aliduffey.bsky.social · 18/10/2025
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
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Ali Duffey @aliduffey.bsky.social · 18/10/2025
"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
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James Dyke @jamesgdyke.info · 17/10/2025
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....
agupubs.onlinelibrary.wiley.com
A Risk‐Risk Assessment of Climate Extremes: Comparing Greenhouse Gas Warming and Stratospheric Aerosol Injection in UKESM1
This study compares the impacts on extreme events under climate change with and without a multi-latitude Stratospheric Aerosol Injection strategy in UKESM1 G6controller reduces extreme heat relat...
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Ali Duffey @aliduffey.bsky.social · 16/10/2025
The NYT piece quoted here is amazing. Written over 70 years ago and reads exactly like articles about this summer's Texas Rainmaker conspiracy
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Ali Duffey @aliduffey.bsky.social · 01/10/2025
love this chart. It's too late for 1.5, but the fight for 2C is very much still alive
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Reposted by Ali Duffey
Marie Le Conte @youngvulgarian.marieleconte.com · 19/09/2025
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
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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.
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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.
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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.
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
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....
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
Not all geoengineering proposals are plausible, and we shouldn't waste time and resources on the implausible ones. Siegert et al look at 5 (really, 6): sea-ice thickening, sea-ice albedo modification, sea-bed curtains, basal water removal from ice sheets, CDR via ocean fertilization, and SAI
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Ali Duffey @aliduffey.bsky.social · 09/09/2025
Is this a crisis or not? Are tipping point risks serious or not? Net zero is non-negotiable, but climate impacts are here, and all plausible emissions scenarios see us pass 1.5C. If now is not a reasonable time to explore radical ideas, when would be?
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Jack Blackburn @hackblackburn.bsky.social · 04/08/2025
One of the all-time great test matches. One of the all-time great series. Topsy-turvy, up and down and, in the end, perfectly balanced. Can't say fairer than that.
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Hannah Ritchie @hannahritchie.bsky.social · 14/07/2025
The Guardian will publish scary headlines about ice sheet and AMOC collapse on a Friday, then stuff like this on a Monday: www.theguardian.com/commentisfre... How are people supposed to navigate this? Is climate change an urgent problem, or not?
theguardian.com
Ed Miliband would let a turbine farm destroy Brontë country. We need net zero, but at what cost? | Simon Jenkins
Of course the climate crisis must be confronted, but history, tranquility and beauty must also count for something, says Guardian columnist Simon Jenkins
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Ali Duffey @aliduffey.bsky.social · 14/07/2025
"some experts are sceptical".. New Scientist has been poor on distinguishing serious and unserious climate intervention ideas recently. There isn't even a peer-reviewed paper making the case for this yet!
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Ali Duffey @aliduffey.bsky.social · 12/07/2025
Yeah, the conspiracy theories are growing in a very scary way
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
A very good if somewhat strange watch. not very informative on risk-reward tradeoffs for solar geo though
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
@eaterofsun.bsky.social might be of interest
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
..and is why a framing of SRM as an "in case of emergency break-glass" type intervention can be misleading
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
BUT, once things are already tipped, SRM might not be able to get you back - we assessed "reversibiility" as ineffective or only partially effective for many important systems. This shouldn't be surprising - this behaviour is part of what makes these things "tipping points"
A long table summarising the main findings of the paper
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
the slight less TLDR version is that SRM likely reduce the strength of driving factors for tipping in a range of systems, generally by reducing temperature but in some cases by restoring other climatic drivers too
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
here's the paper esd.copernicus.org/articles/16/...
esd.copernicus.org
The interaction of solar radiation modification with Earth system tipping elements
Abstract. The avoidance of hitting tipping points has been invoked as a significant benefit of solar radiation modification (SRM) techniques; however, the physical science underpinning this has thus f...
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Ali Duffey @aliduffey.bsky.social · 11/07/2025
Given this context, I'm delighted to share a new review on the solar geoengineering and earth system tipping points. Its a long read including ice sheets, AMOC, coral reefs, Amazon dieback and various others.. TLDR: solar geo probably helps avoid tipping, but a lot more research is needed
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The Alliance for Just Deliberation on Solar Geoengineering @sgdeliberation.bsky.social · 07/07/2025
New opportunity: Become a DSG Fellow and contribute to building critical expertise on solar geoengineering governance. Early- or mid-career and working in climate science, policy, ethics, law, or humanities with an interest in SRM? Apply now: www.sgdeliberation.org/our-work/res...
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Ali Duffey @aliduffey.bsky.social · 07/07/2025
The intro to this paper of mine last year has some potentially useful refs on the hydrological response to SRM, particularly on seperating the fast and slow responses to CO2 iopscience.iop.org/article/10.1... This may all be somewhat tangential to your argument though..
iopscience.iop.org
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