Climate science and technology policy since 1989. Building Climate Systems Engineering at UChicago. Founded Carbon Engineering. Work interferes with my climbing. Read about me and my work at https://davidkeith.earth/https://bsky.app/profile/davidkeith.bsky.socialhttps://bsky.app/profile/davidkeith.bsky.social/post/3mkij4sp7um2bOn May 18–19, the UChicago Climate Systems Engineering initiative is bringing together researchers, policymakers, and practitioners for a public symposium we're calling "Frontiers in Climate Systems Engineering.” The goal is simple: rigorous analysis and open debate.27 Apr 2026 16:40 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3mkij4sp7um2bhttps://bsky.app/profile/davidkeith.bsky.social/post/3m7azkl2cih2zEnjoyed my conversation on SRM360's webinar/pod yesterday. Check it out here: https://srm360.org/video/emissions-cuts-catastrophic-impacts-2025/05 Dec 2025 17:36 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3m7azkl2cih2zhttps://bsky.app/profile/davidkeith.bsky.social/post/3m4ss2vwnk22zDaniele Visioni and I explain our concerns about Stardust and the commercialization of climate engineering in Technology Review: https://www.technologyreview.com/2025/11/04/1127532/why-the-for-profit-race-into-solar-geoengineering-is-bad-for-science-and-public-trust/04 Nov 2025 14:54 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3m4ss2vwnk22zhttps://bsky.app/profile/davidkeith.bsky.social/post/3lzeupro3fk2bNotice how much Ray leans on ad hominem arguments. Calling me a charlatan. So what. It's not about me or Ray. People typically resort to ad hominem attacks when their factual and ethical arguments are weak. Ray: you should do better. [contains quote post or other embedded content]21 Sep 2025 21:48 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lzeupro3fk2bhttps://bsky.app/profile/davidkeith.bsky.social/post/3lzefprzupc23Zeke's sweet thread on our op-ed: [contains quote post or other embedded content]21 Sep 2025 17:20 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lzefprzupc23https://bsky.app/profile/davidkeith.bsky.social/post/3lzefhhv7ej2lZeke Hausfather and I have an NYT op-ed out today, https://www.nytimes.com/2025/09/21/opinion/geoengineering-planet-cooling-sulfur.html Here's my short blog post on the topic: https://davidkeith.earth/preserving-earths-reflectivity-supplementary-comments-on-a-responsible-way-to-cool-the-planet/ 1/421 Sep 2025 17:15 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lzefhhv7ej2lhttps://bsky.app/profile/davidkeith.bsky.social/post/3lukxi46ycs2tResearch on sunlight reflection is often driven by large or badly managed deployments. Ken Caldeira, Cael, and I invite submissions for an AGU session assessing potential harms from limited deployment. https://agu.confex.com/agu/agu25/prelim.cgi/Session/25216822 Jul 2025 16:48 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lukxi46ycs2thttps://bsky.app/profile/davidkeith.bsky.social/post/3lrv736flw42zEnjoyed my time in Cape Town last month for the Degrees Forum 2025. I had the pleasure of joining @hollyjeanbuck.bsky.social and Rose Mutiso for a plenary session on how sunlight reflection methods (SRM) fit into the broader climate response toolbox. #DGF2025 https://youtu.be/jlUQl6YjIjc?si=-Im9L4jikik65fTs&t=23018 Jun 2025 14:15 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lrv736flw42zhttps://bsky.app/profile/davidkeith.bsky.social/post/3lqrxzss4yg2zCan Canada afford to ignore sunlight reflection methods (SRM)? I'm joining @ldilling.bsky.social from the @envdefensefund.bsky.social for a discussion hosted by the Transition Accelerator, a major Canadian NGO focused on the climate. June 10, 12pm ET. Join the Live Q&A: https://transitionaccelerator.ca/webinars/can-we-afford-to-ignore-solar-geoengineering/04 Jun 2025 14:06 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lqrxzss4yg2zhttps://bsky.app/profile/davidkeith.bsky.social/post/3lpuexl43mv2fSuperb op-ed from Steven Pinker (@sapinker on X) calling out the right's absurd Harvard Derangement Syndrome. Harvard has some woke, but its peak has passed, and claims of many on the right are disconnected from the reality I saw as a faculty member. https://www.nytimes.com/2025/05/23/opinion/harvard-university-trump-administration.html23 May 2025 19:37 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lpuexl43mv2fhttps://bsky.app/profile/davidkeith.bsky.social/post/3lptnwbehkf2yI appreciate the way Andreas has made a careful case for strong actions such as civil disobedience to protect humans and nature. Looking fwd having Andreas join us on Energy vs Climate this morning. (Feel free to join us live) https://www.energyvsclimate.com/youre-invited-has-the-world-surrendered-to-climate-breakdown-andreas-malm-author-of-how-to-blow-up-a-pipeline-on-evc-may-23-at-10am-et/23 May 2025 12:45 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lptnwbehkf2yhttps://bsky.app/profile/davidkeith.bsky.social/post/3lpri5u7lpi2kSmart argument against a moratorium for deployment of sunlight reflection SRM from Sue Biniaz (former top US climate negotiator) and @bodansk.bsky.social (environmental lawyer). https://www.justsecurity.org/113295/moratorium-srm-deployment-chilly-reception/ 22 May 2025 15:56 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lpri5u7lpi2khttps://bsky.app/profile/davidkeith.bsky.social/post/3lppm6k2o4k2yNew high-quality survey on public attitudes toward sunlight reflection in Great Britain: 16% support SAI deployment. 46% are unsure. Younger people are more supportive overall. Interesting signals on awareness and openness to geoengineering in general. https://yougov.co.uk/health/articles/52186-dimming-the-sun-brightening-clouds-planting-forests-would-britons-support-geoengineering-to-combat-climate-change 21 May 2025 22:03 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lppm6k2o4k2yhttps://bsky.app/profile/davidkeith.bsky.social/post/3lpmancwzoo2eTerraforming makes me squirm. I don't want to see humans messing with another planet until we have done a much better job protecting Earth's environment. 20 May 2025 13:59 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lpmancwzoo2ehttps://bsky.app/profile/davidkeith.bsky.social/post/3lpk44vosw52wIs Global Cooperation on Climate Change Possible? An interesting conversation with Former Foreign Minister of Pakistan @HinaRKhar, former lead U.S. climate negotiator Sue Biniaz, and former climate advisor to Trump George Banks, moderated by Amy Harder. https://youtu.be/scYZzq3zVm0?si=ZX8YqU2eh2LtsLxL19 May 2025 17:32 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lpk44vosw52whttps://bsky.app/profile/davidkeith.bsky.social/post/3lpcwhvvm6k24Will CO2 emissions peak this year? Mainstream forecasters like @IEA, @RystadEnergy, @McKinsey, and @DNV_Group Det Norske Veritas suggest a peak in the next year or so. Climate advocates seem reluctant to embrace this good news. What do you think? Why might these forcasts be wrong?16 May 2025 21:03 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lpcwhvvm6k24https://bsky.app/profile/davidkeith.bsky.social/post/3loxs6iido62mExcited to be in Cape Town for degreesglobalforum.org/ I last visited this part of the world in 1990, when I ended up in Mozambique during the civil war. Despite all the troubles, it's a different (mostly better) world now. Ping me for meetings. https://degreesglobalforum.org/12 May 2025 10:46 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3loxs6iido62mhttps://bsky.app/profile/davidkeith.bsky.social/post/3lovkmpzgkp26Excited to be on the RBC Disruptors podcast to discuss carbon removal and direct air capture. I did my best to deconstruct the mantra that we need to cut 10 billion tons of carbon emissions a year by 2050. https://thoughtleadership.rbc.com/beyond-offsets-how-to-build-a-carbon-removal-industry/ 11 May 2025 13:26 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lovkmpzgkp26https://bsky.app/profile/davidkeith.bsky.social/post/3lmwllbxots2y"Donald Trump Tries to Run Harvard", here's an extract from this morning's op-ed in the woke Wall Street Journal: [contains quote post or other embedded content]16 Apr 2025 12:25 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lmwllbxots2yhttps://bsky.app/profile/davidkeith.bsky.social/post/3lmukza5akp2zTrump's demands of Harvard are authoritarian. I am proud of Harvard's response. Harvard and similar universities have a problem with insufficient diversity of political viewpoints -- but government power over hiring and speech is precisely the wrong answer. 1/515 Apr 2025 17:10 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lmukza5akp2zhttps://bsky.app/profile/davidkeith.bsky.social/post/3llywi3zldp2oHey Yanks, here is something Canadian you can envy: the opportunity to buy a Mooshead Presidential Pack, 1,461 beers, getting you through Trump, one beer per day of a presidential term. It started as a joke, but they are selling them. https://mooseheadbeershop.ca/products/the-presidential-pack04 Apr 2025 17:20 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3llywi3zldp2ohttps://bsky.app/profile/davidkeith.bsky.social/post/3llytqleafl2jGood article by @catclifford.bsky.social on our work comparing some of the risks and benefits of sulfate aerosol sunlight reflection. https://www.ciphernews.com/articles/geoengineering-quantified-heat-is-deadlier-than-air-pollution/ 1/304 Apr 2025 16:31 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3llytqleafl2jhttps://bsky.app/profile/davidkeith.bsky.social/post/3lkbch347sr2zTerrific and Topical EnergyVSClimate with @jessedjenkins.com https://www.energyvsclimate.com/the-usa-vs-climate-with-dr-jesse-jenkins/13 Mar 2025 14:26 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lkbch347sr2zhttps://bsky.app/profile/davidkeith.bsky.social/post/3lj75huj36k2lI was sitting in NOAA's Boulder lab today when people got fired. Tears in the hallway. Security escort. They fired a great young scientist. Beyond the anti-science nonsense, letting smart & cheap new hires go is an incompetent way to cut costs. https://www.nytimes.com/2025/02/27/climate/noaa-layoffs-trump.html?smid=bs-share28 Feb 2025 00:26 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lj75huj36k2lhttps://bsky.app/profile/davidkeith.bsky.social/post/3lhvtjcidlc2dArticle on the White Sky paper: https://cen.acs.org/environment/atmospheric-chemistry/solar-geoengineering-change-skies/103/web/2025/02?utm_source=ActiveCampaign&utm_medium=email&utm_content=SRM360%20Weekly%20Bulletin&utm_campaign=Weekly%20Bulletin%2011%20Feb [contains quote post or other embedded content]11 Feb 2025 14:09 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lhvtjcidlc2dhttps://bsky.app/profile/davidkeith.bsky.social/post/3lhvtc77bce2pHome in Canada, feeling the cold anger against the treaty-breaking yanks. On Sunday we fantasized about Hydro Quebec pulling the plug on 2.5 GW of power flowing south during the big game. Retool the '80's AB bumper sticker (image): Eastern -> Southern 11 Feb 2025 14:05 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lhvtc77bce2phttps://bsky.app/profile/davidkeith.bsky.social/post/3lhtwln6kwx2xGood article on glacial interventions: https://www.independent.co.uk/news/science/ice-cap-melt-glaciers-preservation-b2694223.html It does a nice job summarizing options. FYI: see the "Research Vission" whitepaper from UChicago: https://climateengineering.uchicago.edu/wp-content/uploads/2024/05/Glacial-Climate-Intervention_A-Research-Vision.pdf 1/210 Feb 2025 19:58 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lhtwln6kwx2xhttps://bsky.app/profile/davidkeith.bsky.social/post/3lhhstk4uru2bUnder a not so white sky: visual impacts of stratospheric aerosol injection New paper out today by Ansar Lemon TLDR: casual observers would not notice anything different about the sky in a world cooled 1 C with stratospheric sulfates. https://iopscience.iop.org/article/10.1088/1748-9326/ada2ae 1/606 Feb 2025 00:19 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lhhstk4uru2bhttps://bsky.app/profile/davidkeith.bsky.social/post/3lh7wxayqlt2tMy solution: Trudeau vs Trump in the ring. As a Candian, I am super pissed at this yank lunacy. This is going to put a lot of folks out of work. (FYI, this Trudeau vs Brazeau boxing match helped Trudeau win the leadership.) https://www.youtube.com/watch?v=XuSpZ3_5pTc&t=628s 1/202 Feb 2025 21:12 +0000at://did:plc:inxh7ajr7maghciastamt5bz/app.bsky.feed.post/3lh7wxayqlt2t