Dagomar Degroot
@dagomardegroot.bsky.social
Professor of environmental history at Georgetown University. Creator, The Climate Chronicles podcast. Author of the new book, "Ripples on the Cosmic Ocean." Interested in all things climate change, outer space, existential risk, and past for present.
Pinned
Solar storms have influenced our history – an environmental historian explains how they could also threaten our future
From communications outages to a brush with nuclear war, solar events like flares and coronal mass ejections have shaped human history.
theconversation.com
My new book, "Ripples on the Cosmic Ocean," was published today! And here's a new article in @theconversation.com that explains how #solarstorms have influenced #history, and may threaten our future. Spoiler: it's really not a good idea to cut science at NASA. theconversation.com/solar-storms...
Reposted by Dagomar Degroot
Last week, @dagomardegroot.bsky.social joined @alimacewen.bsky.social on the Land and Climate Podcast, where he outlined climate shifts throughout history - from the Pleistocene through the Little Ice Age to the current Anthropocene - and their impacts on human civilisation.
Click below to listen!
Click below to listen!
This week, @alimac.bsky.social talks with @dagomardegroot.bsky.social about his new book, “Ripples on the Cosmic Ocean,” they discuss how the solar system has shaped human history and how humanity is now reshaping space.
@penguinrandomhouse.bsky.social
www.landclimate.org/...
@penguinrandomhouse.bsky.social
www.landclimate.org/...
November 10, 2025 at 1:47 PM
Last week, @dagomardegroot.bsky.social joined @alimacewen.bsky.social on the Land and Climate Podcast, where he outlined climate shifts throughout history - from the Pleistocene through the Little Ice Age to the current Anthropocene - and their impacts on human civilisation.
Click below to listen!
Click below to listen!
Reposted by Dagomar Degroot
Okay, here are some first reflections on Watson.
Watson's life is a tragedy, really of Shakespearean proportions. He did not, as most bios will tell you, do one great thing when he was young and then collect laurels for it for the next 60 years. His career arc was unlike any in science.
Watson's life is a tragedy, really of Shakespearean proportions. He did not, as most bios will tell you, do one great thing when he was young and then collect laurels for it for the next 60 years. His career arc was unlike any in science.
November 8, 2025 at 11:22 PM
Okay, here are some first reflections on Watson.
Watson's life is a tragedy, really of Shakespearean proportions. He did not, as most bios will tell you, do one great thing when he was young and then collect laurels for it for the next 60 years. His career arc was unlike any in science.
Watson's life is a tragedy, really of Shakespearean proportions. He did not, as most bios will tell you, do one great thing when he was young and then collect laurels for it for the next 60 years. His career arc was unlike any in science.
I love publishing with @aeon.co. In this article, come for the UAPs (!), stay for the Martian canal-builders - and the history of how they changed our ideas about the environment, our future, and our place in the universe. #EnvHist #Aliens #Mars #History aeon.co/essays/in-th...
In the late 1800s alien ‘engineers’ altered our world forever | Aeon Essays
Images of vast ‘canals’ rippling across the red planet inspired fears of alien ‘engineers’ and changed science forever
aeon.co
November 4, 2025 at 1:54 PM
Reposted by Dagomar Degroot
Your daily dose of climate hope. From the team at RMI: rmi.org/wp-content/u...
November 3, 2025 at 11:36 PM
Your daily dose of climate hope. From the team at RMI: rmi.org/wp-content/u...
What do you do when you see - or think you see - a change in a cosmic environment? I experienced that firsthand one strange night on a rooftop in Washington, DC. Here's my fourth video that introduces my new book, "Ripples on the Cosmic Ocean." #Moon #Astronomy #EnvHist youtu.be/kqCrSyPc8sY
Ripples on the Cosmic Ocean: A Spot on the Moon
YouTube video by Dagomar Degroot
youtu.be
November 3, 2025 at 5:05 PM
What do you do when you see - or think you see - a change in a cosmic environment? I experienced that firsthand one strange night on a rooftop in Washington, DC. Here's my fourth video that introduces my new book, "Ripples on the Cosmic Ocean." #Moon #Astronomy #EnvHist youtu.be/kqCrSyPc8sY
Reposted by Dagomar Degroot
#ICYMI: Environmental historian Dagomar Degroot explains that we can solve a climate issue if we work together... we have done it before! Watch the full #SETILive interview: youtube.com/live/iw7Irsc... 🧪 #podcast #climatechange
November 1, 2025 at 9:01 PM
#ICYMI: Environmental historian Dagomar Degroot explains that we can solve a climate issue if we work together... we have done it before! Watch the full #SETILive interview: youtube.com/live/iw7Irsc... 🧪 #podcast #climatechange
Reposted by Dagomar Degroot
An interstellar comet is such a cool find. It’s really a shame the bright nucleus of this wondrous appearance has been surrounded by an obscuring coma of alien conspiracy.
The Harvard astronomer responsible for that is doing sizable harm to the fields of speculative science he claims to represent.🧪
The Harvard astronomer responsible for that is doing sizable harm to the fields of speculative science he claims to represent.🧪
3I/ATLAS is behaving just as a comet should. No shenanigans. Looking forward to the possibility of JUICE (a European spacecraft heading eventually to Jupiter) observing this object in the coming weeks!
I have just received from Kevin Walsh of SWRI a re-analysis of the PUNCH data for 3I/ATLAS, & have redone our gas and dust coma prediction models as a result. These new data agree well with the independent reductions of Thomas Lehmann and bode well for the Juice observations starting November 2nd.
October 31, 2025 at 4:02 PM
An interstellar comet is such a cool find. It’s really a shame the bright nucleus of this wondrous appearance has been surrounded by an obscuring coma of alien conspiracy.
The Harvard astronomer responsible for that is doing sizable harm to the fields of speculative science he claims to represent.🧪
The Harvard astronomer responsible for that is doing sizable harm to the fields of speculative science he claims to represent.🧪
Three new interviews about the #EnvHist of outer space and climate change!
It was an absolute delight to chat about "Ripples on the Cosmic Ocean" with Sarah Al-Ahmed at Planetary Radio, one of my favorite podcasts. Check it out here: www.planetary.org/planetary-ra... (1/3)
It was an absolute delight to chat about "Ripples on the Cosmic Ocean" with Sarah Al-Ahmed at Planetary Radio, one of my favorite podcasts. Check it out here: www.planetary.org/planetary-ra... (1/3)
Ripples on the Cosmic Ocean
Historian Dagomar Degroot joins Planetary Radio to discuss his new book, “Ripples on the Cosmic Ocean: An Environmental History of Our Place in the Solar…
www.planetary.org
October 30, 2025 at 4:12 PM
Three new interviews about the #EnvHist of outer space and climate change!
It was an absolute delight to chat about "Ripples on the Cosmic Ocean" with Sarah Al-Ahmed at Planetary Radio, one of my favorite podcasts. Check it out here: www.planetary.org/planetary-ra... (1/3)
It was an absolute delight to chat about "Ripples on the Cosmic Ocean" with Sarah Al-Ahmed at Planetary Radio, one of my favorite podcasts. Check it out here: www.planetary.org/planetary-ra... (1/3)
Solar system environments aren't distant frontiers. They're actors that have shaped our history, and may hold the key for our future. In this new article for @nautil.us, I share three big revelations from writing "Ripples on a Cosmic Ocean." #EnvHist #Space nautil.us/what-happens...
What Happens in Space Matters on Earth
What Happens in Space Matters on Earth: Dagomar Degroot’s three greatest revelations while writing Ripples on a Cosmic Ocean
nautil.us
October 29, 2025 at 3:45 PM
Solar system environments aren't distant frontiers. They're actors that have shaped our history, and may hold the key for our future. In this new article for @nautil.us, I share three big revelations from writing "Ripples on a Cosmic Ocean." #EnvHist #Space nautil.us/what-happens...
Reposted by Dagomar Degroot
THIS!!! 👇👇👇 If you ever hear a solar storm described as a “Carrington-level event”, you have my permission to freak out.
My new book, "Ripples on the Cosmic Ocean," was published today! And here's a new article in @theconversation.com that explains how #solarstorms have influenced #history, and may threaten our future. Spoiler: it's really not a good idea to cut science at NASA. theconversation.com/solar-storms...
Solar storms have influenced our history – an environmental historian explains how they could also threaten our future
From communications outages to a brush with nuclear war, solar events like flares and coronal mass ejections have shaped human history.
theconversation.com
October 29, 2025 at 2:43 PM
THIS!!! 👇👇👇 If you ever hear a solar storm described as a “Carrington-level event”, you have my permission to freak out.
My new book, "Ripples on the Cosmic Ocean," was published today! And here's a new article in @theconversation.com that explains how #solarstorms have influenced #history, and may threaten our future. Spoiler: it's really not a good idea to cut science at NASA. theconversation.com/solar-storms...
Solar storms have influenced our history – an environmental historian explains how they could also threaten our future
From communications outages to a brush with nuclear war, solar events like flares and coronal mass ejections have shaped human history.
theconversation.com
October 28, 2025 at 5:07 PM
My new book, "Ripples on the Cosmic Ocean," was published today! And here's a new article in @theconversation.com that explains how #solarstorms have influenced #history, and may threaten our future. Spoiler: it's really not a good idea to cut science at NASA. theconversation.com/solar-storms...
In 1859, a solar storm of staggering power revealed that while technological progress had provided new powers over environments on Earth, it had also created vulnerabilities to environments in space. Read more in this excerpt from Ripples on the Cosmic Ocean! #EnvHist lithub.com/on-the-19th-...
On the 19th-Century Scientist Who Realized Solar Storms Influence Life on Earth
When thirty-three-year-old Richard Carrington settled down to sketch sunspots on the morning of September 1, 1859, he could not have known that he was about to witness the most important change eve…
lithub.com
October 27, 2025 at 3:04 PM
In 1859, a solar storm of staggering power revealed that while technological progress had provided new powers over environments on Earth, it had also created vulnerabilities to environments in space. Read more in this excerpt from Ripples on the Cosmic Ocean! #EnvHist lithub.com/on-the-19th-...
Reposted by Dagomar Degroot
if you’re a Boston Brahmin, Masshole or even a chowderhead, come out to the Boston Book Festival today at 4:30 for my panel with @dagomardegroot.bsky.social on placing humanity in its geologic and cosmic context bostonbookfestival2025.sched.com/event/28bfb/...
Boston Book Festival 2025: Science: Planetary and Cosmic Histories
View more about this event at Boston Book Festival 2025
bostonbookfestival2025.sched.com
October 25, 2025 at 3:08 PM
if you’re a Boston Brahmin, Masshole or even a chowderhead, come out to the Boston Book Festival today at 4:30 for my panel with @dagomardegroot.bsky.social on placing humanity in its geologic and cosmic context bostonbookfestival2025.sched.com/event/28bfb/...
Really enjoyed answering some truly thought-provoking questions in this Reddit AMA - a first for me! #EnvHist www.reddit.com/r/AskHistori...
From the AskHistorians community on Reddit: What does history tell us about humanity’s future? I’m Dagomar Degroot, the NASA Chair of Astrobiology at the Library of Congress and author of RIPPLES ON T...
Explore this post and more from the AskHistorians community
www.reddit.com
October 24, 2025 at 7:46 PM
Really enjoyed answering some truly thought-provoking questions in this Reddit AMA - a first for me! #EnvHist www.reddit.com/r/AskHistori...
I really enjoyed doing this interview with Isaac Randel of Foreword Reviews. The questions were incredibly thought-provoking, exploring everything from today's existential risks to the history of the search for alien life. #EnvHist #Space www.forewordreviews.com/articles/art...
October 24, 2025 at 2:06 PM
I really enjoyed doing this interview with Isaac Randel of Foreword Reviews. The questions were incredibly thought-provoking, exploring everything from today's existential risks to the history of the search for alien life. #EnvHist #Space www.forewordreviews.com/articles/art...
Reposted by Dagomar Degroot
Idk how to study the solar system's environmental history but I'm ready to learn in today's AMA with @dagomardegroot.bsky.social on @askhistorians.bsky.social (with r/AskScience too!)
www.reddit.com/r/AskHistori...
www.reddit.com/r/AskHistori...
From the AskHistorians community on Reddit: What does history tell us about humanity’s future? I’m Dagomar Degroot, the NASA Chair of Astrobiology at the Library of Congress and author of RIPPLES ON T...
Explore this post and more from the AskHistorians community
www.reddit.com
October 24, 2025 at 1:31 PM
Idk how to study the solar system's environmental history but I'm ready to learn in today's AMA with @dagomardegroot.bsky.social on @askhistorians.bsky.social (with r/AskScience too!)
www.reddit.com/r/AskHistori...
www.reddit.com/r/AskHistori...
Reposted by Dagomar Degroot
@dagomardegroot.bsky.social has a new book coming out this month. "Ripples on the Cosmic Ocean" is a reimagining of the solar system and its influence on history. In this video, Professor Degroot explains how the Earth records its past and how the history of environmental changes... 🧪
October 23, 2025 at 11:00 PM
@dagomardegroot.bsky.social has a new book coming out this month. "Ripples on the Cosmic Ocean" is a reimagining of the solar system and its influence on history. In this video, Professor Degroot explains how the Earth records its past and how the history of environmental changes... 🧪
Tomorrow morning EST: I'm doing a Reddit AMA with r/AskHistorians and r/AskScience. I'll answer any and all questions about #ClimateChange, space history, environmental history, and anything else people want to talk about - including "Ripples on the Cosmic Ocean," my next book. #EnvHist
October 23, 2025 at 3:52 PM
Tomorrow morning EST: I'm doing a Reddit AMA with r/AskHistorians and r/AskScience. I'll answer any and all questions about #ClimateChange, space history, environmental history, and anything else people want to talk about - including "Ripples on the Cosmic Ocean," my next book. #EnvHist
Talk about good timing, with the release of "Ripples on the Cosmic Ocean" less than a week away! #EnvHist #Space www.sciencedaily.com/releases/202...
A giant wave is rippling through the Milky Way, and scientists don’t know why
Our Milky Way is far from calm — it ripples with a colossal wave spanning tens of thousands of light-years, revealed by ESA’s Gaia telescope. This wave, moving through the galaxy’s disc like ripples i...
www.sciencedaily.com
October 22, 2025 at 1:22 PM
Talk about good timing, with the release of "Ripples on the Cosmic Ocean" less than a week away! #EnvHist #Space www.sciencedaily.com/releases/202...
An interesting study on the risks of #geoengineering - or more precisely the kind of geoengineering that would inject aerosols into the stratosphere.
But I don't understand how you do a study like this without involving humanists and social scientists. #ClimateChange www.nature.com/articles/s41...
But I don't understand how you do a study like this without involving humanists and social scientists. #ClimateChange www.nature.com/articles/s41...
Engineering and logistical concerns add practical limitations to stratospheric aerosol injection strategies - Scientific Reports
Scientific Reports - Engineering and logistical concerns add practical limitations to stratospheric aerosol injection strategies
www.nature.com
October 22, 2025 at 1:21 PM
An interesting study on the risks of #geoengineering - or more precisely the kind of geoengineering that would inject aerosols into the stratosphere.
But I don't understand how you do a study like this without involving humanists and social scientists. #ClimateChange www.nature.com/articles/s41...
But I don't understand how you do a study like this without involving humanists and social scientists. #ClimateChange www.nature.com/articles/s41...
Reposted by Dagomar Degroot
The late 1450s eruption (eruptions?) continues to be an odd one www.nature.com/articles/s43...
Origin of the 1458/59 CE volcanic eruption revealed through analysis of glass shards in the firn core from Antarctic Vostok station - Communications Earth & Environment
The 1458/59 CE cryptotephra in the Antarctic Vostok Station firn core shows a bimodal distribution of dacite and rhyolite, sourced from the Kuwae and potentially an unrecorded southern high-latitude e...
www.nature.com
October 22, 2025 at 12:23 AM
The late 1450s eruption (eruptions?) continues to be an odd one www.nature.com/articles/s43...
Super excited for this!
2026 Canadian History & Environment Summer School is going to Prince Edward Island!!
The theme of CHESS 2026 is Climate & History. Keynotes by @dagomardegroot.bsky.social & Liza Piper.
Apply to attend the PREMIER Canadian #EnvHist Event by 30 November 2025.
niche-canada.org/2025/10/20/c...
The theme of CHESS 2026 is Climate & History. Keynotes by @dagomardegroot.bsky.social & Liza Piper.
Apply to attend the PREMIER Canadian #EnvHist Event by 30 November 2025.
niche-canada.org/2025/10/20/c...
CHESS 2026: Climate & History - Call for Participants
We are pleased to invite applications to attend the 2026 Canadian History & Environment Summer School.
niche-canada.org
October 20, 2025 at 9:00 PM
Super excited for this!
In my third video introducing my new book, "Ripples on the Cosmic Ocean," I explain how the #telescope allows us to see the true nature of reality, and I show how I used telescopes to write an environmental history of the solar system. #EnvHist #Space #Astronomy youtu.be/nlal2Ke6QJw
Ripples on the Cosmic Ocean: The Telescope
YouTube video by Dagomar Degroot
youtu.be
October 20, 2025 at 1:42 PM
In my third video introducing my new book, "Ripples on the Cosmic Ocean," I explain how the #telescope allows us to see the true nature of reality, and I show how I used telescopes to write an environmental history of the solar system. #EnvHist #Space #Astronomy youtu.be/nlal2Ke6QJw
I'm truly honored to be awarded the @eseh.bsky.social Bristol-Bern Prize for The Climate Chronicles. It really motivates me to keep working on the third and fourth seasons! I'm sharing the award with chanelle.bsky.social, whose "Ghost Tours" looks incredible. #EnvHist
eseh.org/2025-bristol...
eseh.org/2025-bristol...
2025 Bristol-Bern Prize – European Society for Environmental History
eseh.org
October 17, 2025 at 2:46 PM
I'm truly honored to be awarded the @eseh.bsky.social Bristol-Bern Prize for The Climate Chronicles. It really motivates me to keep working on the third and fourth seasons! I'm sharing the award with chanelle.bsky.social, whose "Ghost Tours" looks incredible. #EnvHist
eseh.org/2025-bristol...
eseh.org/2025-bristol...
Reposted by Dagomar Degroot
@dagomardegroot.bsky.social has a new book coming out this month. "Ripples on the Cosmic Ocean" is a reimagining of the solar system and its influence on history. In this video, Professor Degroot explains how growing up with big dreams and tragedy in a small Canadian town led him... 🧪
October 16, 2025 at 11:01 PM
@dagomardegroot.bsky.social has a new book coming out this month. "Ripples on the Cosmic Ocean" is a reimagining of the solar system and its influence on history. In this video, Professor Degroot explains how growing up with big dreams and tragedy in a small Canadian town led him... 🧪