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Dagomar Degroot

@dagomardegroot.bsky.social
2.5K followers 154 following 197 posts

Professor of environmental history at Georgetown University. Creator, "The Climate Chronicles." Author of the new book, "Ripples on the Cosmic Ocean." Interested in all things climate change, outer space, existential risk, and past for present.

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Dagomar Degroot @dagomardegroot.bsky.social · 22/09/2026
As @zekehausfather.com and David Wallace-Wells put it: although worst-case scenarios for #ClimateChange seem less likely than they once did, they're still very much in play. That was also my takeaway while writing the scenarios in After2c (after2c.com). www.nytimes.com/2026/09/22/o...
nytimes.com
Opinion | Climate Catastrophe Is Still on the Table
Harrowing temperature increases remain unnervingly possible.
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Royal Historical Society @royalhistsoc.org · 20/09/2026
Coming up this week, the Society hosts two events on history and the environment. The first, at 1pm on Thurs 24th, offers 'Historical Context' on 'The Climate Crisis': bit.ly/3V4lgKf With panellists @dagomardegroot.bsky.social, @sadiahqureshi.bsky.social and bsky.app/profile/elly... All welcome.
eventbrite.co.uk
Historical Context: The Climate Crisis
A panel discussion, hosted by the Royal Historical Society, in which expert historical researchers provide context for current events.
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Zeke Hausfather @zekehausfather.com · 16/09/2026
All the September dynamical ENSO models (including SINTEX) are now in, and they give a 100% chance of a record event this year using the Oceanic Niño Index (ONI) metric:
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Kevin Anchukaitis @thirstygecko.bsky.social · 10/09/2026
Projected amplification of global warming by warming-induced greenhouse gas emissions '[Warming-induced emissions] could add 0.2 °C–0.4 °C of warming by 2100' iopscience.iop.org/article/10.1...
iopscience.iop.org
Projected amplification of global warming by warming-induced greenhouse gas emissions
Projected amplification of global warming by warming-induced greenhouse gas emissions, Abernethy, Sam, Monteverde, Danielle, Schädel, Christina, Buma, Brian, Duffy, Philip B, Jackson, Robert B, Natali, Susan M, Ocko, Ilissa, Rogers, Brendan M, Poulter, Benjamin
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
Here are two new pieces, by historians, that I found interesting: www.hnn.us/article/ai-i... activehistory.ca/blog/2026/09... Here's something on LLMs in climate history: www.journals.uchicago.edu/doi/abs/10.1... And in climate work more broadly: www.theclimatebrink.com/p/the-ai-aug...
hnn.us
AI Is an Anti-Primary Source Machine
Real voices from the past are threatened by chatbots designed to amplify — and ultimately become — the loudest voices in the room.
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
We're all trying to wrestle with the implications and ethics of LLMs. It's inevitable that we'll come up with different opinions on whether (or how) to use LLMs in the classroom, as researchers and writers - and at home. We can disagree and debate - without assuming the worst in each other. (10/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
Overall, we have to be able to accept that LLMs come with serious costs, profound dangers... and enormous potential. Their emergence and development is a complex problem if ever there was one. It may be the most interesting and important feature of our time. (9/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
...and does much of what a frontier model can do. These models aren't disappearing. And to gain a sense of where the tech is going, it's important to remember that analysts have biases and incentives. We can't abandon critical thinking because we want to believe something! (8/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
5. AI isn't going away. The continued use of LLMs doesn't depend on the survival of a particular company. It doesn't even depend on corporate profitability. Anyone can use a program like Ollama to download an open weight model, for free, that works on most laptops... (7/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
Or changed the layout of my document? Have I used the LLM to conduct the research that informed my writing, or merely to perform an initial reconnaissance of published work? Was an LLM used to write the articles I read to research? The "how" questions matter more than the "what" questions. (6/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
4. When you say you used an LLM to do a task, or accuse others of doing so, you aren't saying much of anything. If I say I've used an LLM to write, for example, does that mean it's written something for me? Or copyedited something? Fact checked? Has it suggested rewording specific sentences? (5/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
Running a local LLM, on your laptop can use only as much energy as a video game. Still, there is genuine environmental danger. It lies in future CO2 emissions associated with a rapid data center buildup in parts of countries (the US!) where power comes from fossil fuels. See: after2c.com. (4/10)
after2c.com
After 2C - Histories of the Future of Global Warming
An interactive exploration of five plausible, research-grounded climate futures, written as history papers looking back from the year 2100.
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
3. It's not so easy to pin down the environmental costs of LLMs. Models vary, and energy costs can be calculated from training, not regular operation. US data centers use a lot of water, but at present only a minuscule % of total US water use. And this is all for cloud-based LLMs. (3/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
2. There is no one "AI." There is no universal "LLM." If you say "AI does x," or "LLMs cannot do y," you are probably wrong. These are diverse, rapidly evolving systems. A free LLM from (pick your company) might be useless at a task easily performed by a frontier model. (2/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
There's been some really interesting debate here on #AI in history. Here are five basic things to keep in mind. 1. Terminology matters! AI is not the same as LLMs. Machine learning is a branch of AI. Deep learning is a branch of machine learning. LLMs are a family of deep-learning systems. (1/10)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
What is space weather, exactly? How can it affect Earth? What's the worst that could happen? What does history teach us, and what might the future have in store? The guide answers all of those questions, and more. (2/2)
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Dagomar Degroot @dagomardegroot.bsky.social · 09/09/2026
I'm grateful to the Conversation for assembling this unique guide to #SpaceWeather. It's based on five recent articles, including my new piece drawing from my book, Ripples on the Cosmic Ocean. (1/2) #EnvHist #SolarStorms theconversation.com/space-weathe...
theconversation.com
Space weather can cause both beautiful auroras and infrastructure challenges – 5 essential reads on protecting life and technology
A massive solar flare could seriously disrupt life on Earth – but new NASA missions and others in development will help monitor the Sun.
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Dagomar Degroot @dagomardegroot.bsky.social · 02/09/2026
In the article, I identify five trends that, I think, are coalescing to make a food crisis much more likely. A lot depends on the strengthening #ElNiño, and I think the article leads with one of the clearest visualizations currently available of what El Niño could look like in December.
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Dagomar Degroot @dagomardegroot.bsky.social · 02/09/2026
I really hope I got this wrong. But I believe the stage is set for a global food crisis, the likes we haven’t seen since the 1970s. Will it materialize in the coming year? In this article, I break it down. #ElNino #GlobalWarming #Iran #Ukraine sciencepolitics.org/2026/09/02/t...
sciencepolitics.org
The Coming Global Food Crisis? - Science Politics
A Warning...
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Tennant Reed @tennantreed.bsky.social · 27/08/2026
The project is a website, after2c.com, drawing on published research, recent history and speculative fiction in a very interesting way. By Prof @dagomardegroot.bsky.social and his Existential Risk class students.
after2c.com
After 2C - Histories of the Future of Global Warming
An interactive exploration of five plausible, research-grounded climate futures, written as history papers looking back from the year 2100.
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NiCHE Canada @nichecanada.bsky.social · 20/08/2026
Today @dagomardegroot.bsky.social introduces After 2C, Histories of the Future of Global Warming Can today’s history students shape the future of climate change? And how will the history students of the future remember global warming? niche-canada.org/2026/08/20/i... #envhist #climatechange
niche-canada.org
Introducing: After 2C, Histories of the Future of Global Warming
Can history students shape our climate future? Explore After2C, an interactive site using plausible future histories to examine global warming, geoengineering, and climate hope.
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Dr. Lucky Tran @luckytran.com · 17/08/2026
US child vaccination rates have plunged since before the pandemic, with kindergarten classrooms in more than 70% of counties now lacking herd immunity against measles.
US choropleth map showing percentage change in MMR or overall vaccination rates since before the pandemic, by county. Decreases are shown in pink, increases in green.
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Dagomar Degroot @dagomardegroot.bsky.social · 13/08/2026
Every month, I'll update the site with important new publications. The goal is to create a landing spot for anyone who's interested in this most critical of #GlobalWarming topics: scholars, students, journalists, policymakers, and of course, the general public.
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Dagomar Degroot @dagomardegroot.bsky.social · 13/08/2026
The worst risks associated with #ClimateChange are linked to "tipping elements," parts of the climate system that could quickly and all but irreversibly enter new states. I created a website that maps these tipping elements and collects the newest research about them. www.climatetippingpoints.com
climatetippingpoints.com
Climate Tipping Points
Explore an interactive atlas of climate tipping points and tipping elements, with continuously updated research on thresholds, consequences, uncertainty, and connections.
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Dagomar Degroot @dagomardegroot.bsky.social · 13/08/2026
I'd really hoped that BlueSky would be better than Twitter.
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Dagomar Degroot @dagomardegroot.bsky.social · 12/08/2026
I hope that the site is illuminating: scary in places, encouraging in others. And I hope that it provides a model for the kinds of projects we can do with students who might be fearful or depressed about the future. Projects that can overcome despair through action. (5/5)
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Dagomar Degroot @dagomardegroot.bsky.social · 12/08/2026
Because these futures are presented as history papers, they can dive deeply into the complexities of climate adaptation, mitigation, and geoengineering – exploring tradeoffs, unintended consequences, and path dependencies. (4/5)
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Dagomar Degroot @dagomardegroot.bsky.social · 12/08/2026
The site begins with a fictional history paper about a global catastrophe in 2046, brought on by a powerful El Niño. From there, it explores four plausible futures, some considerably more frightening than others. (3/5)
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Dagomar Degroot @dagomardegroot.bsky.social · 12/08/2026
After2C began as a project in “Existential Risk,” an undergraduate seminar I taught last semester. Inspired by my students’ work, I spent much of the summer developing the project into a public resource. (2/5)
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Dagomar Degroot @dagomardegroot.bsky.social · 12/08/2026
I’m thrilled to introduce a major new project: “After 2C.” It’s an interactive website that tries to answer a simple question: how will the history students of the future write about global warming in our century? (1/5) #ClimateChange #GlobalWarming #ElNino #EnvHist after2c.com
after2c.com
After 2C - Histories of the Future of Global Warming
An interactive exploration of five plausible, research-grounded climate futures, written as history papers looking back from the year 2100.
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Kat Long @katlong.bsky.social · 28/07/2026
New from me: Climate change is eating away at Svalbard's largest whalers' graveyard, threatening bones and textiles preserved in the 17th-century burials as well as the scientific data embedded in them 🧪⚱️❄️
nationalgeographic.com
Thawing permafrost is threatening Svalbard's 'corpse point'
Human bones and artifacts from the largest whalers’ graveyard in the archipelago are at risk of disintegrating.
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Dagomar Degroot @dagomardegroot.bsky.social · 13/07/2026
My take on #America250. Both trends and anomalies in weather have shaped the history of the United States. And if we don't restore efforts to slash greenhouse gas emissions, #ClimateChange could make for a grim 300th. sciencepolitics.org/2026/07/13/h... #ClimateChange #America250
sciencepolitics.org
How Climate Change and Weather Shaped 250 Years of U.S. History - Science Politics
Cold, rain, drought, and warming have both helped and harmed Americans' efforts at pivotal moments.
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NiCHE Canada @nichecanada.bsky.social · 06/07/2026
ICYMI: @harrycroft.bsky.social reflects on his experience at our Canadian History of the Enviornment Summer School in PEI! niche-canada.org/2026/07/04/s... #envhist #cdnhist #PEI
niche-canada.org
Speed CHESS 2026: A First-Timer's Account
Harrison Croft, a Germany-based historian, attended the CHESS meeting in PEI, exploring climate resilience, parabolic sand dunes, and local environmental histories.
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Zeke Hausfather @zekehausfather.com · 06/07/2026
July ECMWF runs are in and forecast an even more extreme El Niño event than the prior June runs. ENSO3.4 region temperatures reach 3.9C in December, and forecasts are around 0.3C warmer than they were in June.
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Simon Evans @drsimevans.carbonbrief.org · 02/07/2026
Did you know? Renewables have just overtaken coal as the world's largest source of electricity 34% – global renewable share, up 2x in 20yrs 48% – EU 37% – China 26% – US 24% – India
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Dagomar Degroot @dagomardegroot.bsky.social · 02/07/2026
Want to write a peer-reviewed, Oxford Intersections article on the #EnvHist of disasters? Check out our call for papers! Oxford Intersections offers a quick, respected, high-impact publishing format - perfect for new research in environmental history. academic.oup.com/oxford-inter...
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Dagomar Degroot @dagomardegroot.bsky.social · 24/06/2026
I'm so sorry to read this. You're such an essential voice. Pulling for you, and for your colleagues!
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Dagomar Degroot @dagomardegroot.bsky.social · 24/06/2026
Clare is a remarkable person in so many ways. This is vital reading.
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Dagomar Degroot @dagomardegroot.bsky.social · 18/06/2026
What a profound relief, my God.
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Dagomar Degroot @dagomardegroot.bsky.social · 18/06/2026
Big histories of #ClimateChange are always full of mistakes, partly because climate science is constantly changing. Because my "Climate Chronicles" is not a book, I can fix my errors. I've now published a list of the revisions I plan to make this year. #EnvHist theclimatechronicles.com/revisions/
theclimatechronicles.com
Revisions - The Climate Chronicles
The Climate Chronicles attempts to explain how climate change shaped the history of our species. That’s a daunting challenge, for at least three reasons.
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Kevin Anchukaitis @thirstygecko.bsky.social · 11/06/2026
This really would be the end of science in the US marginalrevolution.com/marginalrevo...
marginalrevolution.com
The Nationalization of American Science - Marginal REVOLUTION
OMB, joined by some forty grantmaking agencies—NSF, HHS, DOE, NASA, DOD among them—has proposed a sweeping rewrite of the rules governing all federal grants, the Regulation for Federal Financial Assis...
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Dagomar Degroot @dagomardegroot.bsky.social · 11/06/2026
Today at 5 PM EST! Join @amandagefter.bsky.social and me for a conversation that spans Earth and the solar system, exploring how natural and human histories intersect. We'll talk about everything from #climatechange to #alien civilizations - it should be fun. #EnvHist #Astronomy luma.com/apv6a38z
luma.com
Space Weather and the Course of History · Zoom · Luma
Often when we think of space we think of “out there.” The wonders beyond. But out there includes us! Let’s talk about the weather. On Earth it can delight or…
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NiCHE Canada @nichecanada.bsky.social · 22/05/2026
Event - Reflections on Resilience: 20,000 Years of Climate History A Climate History Plenary with @dagomardegroot.bsky.social Part of #CHESS2026 Sunday – 31 May 2026 – 17:30-18:45 ADT Murphy Student Centre 110 (McMillan Hall) – University of Prince Edward Island niche-canada.org/2026/05/22/e...
niche-canada.org
Event - Reflections on Resilience: 20,000 Years of Climate History
31 May 2026 - Charlottetown, Prince Edward Island - Dr. Dagomar Degroot is a leading climate historian from Georgetown University. He has published several high-impact, award-winning books on climate ...
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Nature Portfolio @natureportfolio.nature.com · 12/05/2026
A study in Nature Sustainability shows sea-level rise is already causing population retreat in coastal Louisiana and uses geological history and demographic data to argue that early, planned relocation can guide global climate adaptation. go.nature.com/4eHOh6q 🌍🌊🧪
This is figure 4, which shows population change along the US Gulf Coast, Louisiana to Florida (2000–2024).
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Dagomar Degroot @dagomardegroot.bsky.social · 13/05/2026
It can also be used to dramatically improve the appearance of visuals you’ve already created… maybe an even more useful application for many researchers.
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Dagomar Degroot @dagomardegroot.bsky.social · 12/05/2026
Oh, I worry too!
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Dagomar Degroot @dagomardegroot.bsky.social · 12/05/2026
As @climatechirper.bsky.social says, "The deliberate actions of colonialists in the 1870s disrupted local systems that communities relied on for being resilient to climate variations." So, it's wrong to claim that it was #ElNino that killed millions in 1877. www.washingtonpost.com/weather/2026...
washingtonpost.com
A super El Niño wiped out millions of people in 1877. Are we better prepared now?
The climatic phenomenon is expected to return this year, but a lot has changed since what might have been the worst environmental disaster in human history.
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Dagomar Degroot @dagomardegroot.bsky.social · 09/05/2026
No. Instead of thinking, "what do people want to hear, and how can I give it to them?", politicians should ask, "what do I think is important, how can I explain why it's important, and how can I offer solutions?" Authenticity matters, now more than ever. #Climate www.nytimes.com/2026/05/09/o...
nytimes.com
Opinion | Forget Climate Change. Democrats Need to Talk About Other Issues.
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Dagomar Degroot @dagomardegroot.bsky.social · 07/05/2026
EM artists worked in the Little Ice Age. Their art didn't necessarily record the effects of climate change. It can't simply tell us how to survive global warming. But climate change clearly played a role in the creation and consumption of EM art. And that must be part of art history. (2/2) #EnvHist
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