Sign in

John Andrew Higgins

@blueicedude.bsky.social
1.5K followers 1.2K following 96 posts

Professor, Department of Geosciences, Princeton University. I am a chemist interested in the history of the Earth as recorded in polar ice cores and the rock record and envrionmental justice. Views are my own and not my institution.

PostsRepliesMedia
John Andrew Higgins @blueicedude.bsky.social · 07/10/2026
I don't think this is true. Walk me through how this works - i.e. how suing then into bankruptcy stops climate change.
000
Reposted by John Andrew Higgins
Lamont-Doherty Earth Observatory @lamont.columbia.edu · 10/09/2026
📣 Job Alert! @lamont.columbia.edu's Geochemistry division seeks an Associate Research Scientist to conduct paleoclimate and ice core research, mentor students and junior scientists, write scientific papers and grant proposals, and more. ➡️ Learn more/apply/share: bit.ly/4cxco5U
Geochemistry building on the Lamont-Doherty Earth Observatory campus in Palisades, NY. Credit: Miriam Cinquegrana
055
John Andrew Higgins @blueicedude.bsky.social · 02/09/2026
That's the geologic perspective I'm looking for!
010
John Andrew Higgins @blueicedude.bsky.social · 18/07/2026
One of these is not like the other!
000
John Andrew Higgins @blueicedude.bsky.social · 08/07/2026
The line between believing a scientific result strongly enough to advocate for it with zeal and becoming a zealot is a thin one!
000
John Andrew Higgins @blueicedude.bsky.social · 07/07/2026
and getting three ready in the morning?
010
John Andrew Higgins @blueicedude.bsky.social · 22/06/2026
The work of reviewing the proposals has already been done for you. All those people you pay to run your grant programs should just to to fund more science. Don’t take any more researchers time having us craft our work to your narrative. NSF has already done all the work for you! 2/2.
110
John Andrew Higgins @blueicedude.bsky.social · 22/06/2026
All you foundations and wealthy universities should be funding the rejected proposals from NSF. Get rid of all the overhead associated with having your own funding process. There will be an abundance of highly rated and expertly vetted science that will not get funded as a result of these cuts 1/2
162
John Andrew Higgins @blueicedude.bsky.social · 17/06/2026
Indeed! Nice work. 👍
000
John Andrew Higgins @blueicedude.bsky.social · 17/06/2026
And yet it's the one that we're usually desperately trying to avoid as it's the least interesting outcome. Over-interpreting data to tell a great story is a pox on our field!
130
John Andrew Higgins @blueicedude.bsky.social · 03/06/2026
I chose to celebrate by violating my Unis new 'Bike Policy'. No e-bike for me! Back to the F-150.
110
John Andrew Higgins @blueicedude.bsky.social · 21/05/2026
Volcanoes are cool. Except when they erupt and then they’re really hot. Like really hot. And loud. And generally fucking awesome. Highly recommend.
0121
John Andrew Higgins @blueicedude.bsky.social · 15/05/2026
Scientists: Well our best guess for extinction-causing climate change from the Earth History is probably catastrophic cooling associated with stratospheric aerosols. Tech bros: Well that COULD happen but I could also save the world and become a gazillionaire! LFG! Fermi paradox answered.
020
John Andrew Higgins @blueicedude.bsky.social · 12/05/2026
It’s 😎 to wear helmets kids! Take it from this 😎 dad.
020
John Andrew Higgins @blueicedude.bsky.social · 10/05/2026
Is Bluesky just LinkedIn light? Are there substantive scientific discussions to be had here? Or just a lot of horn tooting and finger wagging?
000
John Andrew Higgins @blueicedude.bsky.social · 10/05/2026
I mean the shade thrown at blue ice is lame imo (it turns out all Earth history is complicated!) but whaddya gonna do. Media is gonna media. I was excited to see that no mean change in CO2 across the MPT seems to be robust. Eager to see what you find in the disturbed basal bits!
010
John Andrew Higgins @blueicedude.bsky.social · 07/05/2026
Woop woop for N isotopes and a deeper understanding of the origins of Pleistocene glacial cycles!
070
John Andrew Higgins @blueicedude.bsky.social · 06/05/2026
Serious FOMO over here in the USA while all the new data from Beyond EPICA. Whose got the 🫖 @tinyicybubbles.bsky.social?!
160
Reposted by John Andrew Higgins
Bob Kopp @bobkopp.net · 31/03/2026
One fun facts about GWPs: those passionately arguing for 20-year GWPs over 100-year GWPs probably would not passionately argue for a 7% discount rate over a 3% discount rate (and might, correctly, think 3% is too high for long-lasting societal risks) yet mathematically these are almost the same
3315
John Andrew Higgins @blueicedude.bsky.social · 28/04/2026
Today I learned what the expression 'soup to nuts' actually means. Makes a lot more sense now, but who eats nuts for dessert?!
110
John Andrew Higgins @blueicedude.bsky.social · 28/04/2026
Absolutely. I think that overselling the public on solutions that don’t work will further erode trust and screw things up for the solutions that do. Small world though, last time I saw Dr. Walker we were hiding from 🐘 in Namibia!
010
John Andrew Higgins @blueicedude.bsky.social · 25/04/2026
Why is it that they always use the stock photo of McMurdo when posting bad news about NSF?! www.washingtonpost.com/science/2026...
washingtonpost.com
Trump ousts National Science Board members
Members of the independent board that guides the National Science Foundation said they received a notice from the White House that their position was being terminated.
020
John Andrew Higgins @blueicedude.bsky.social · 23/04/2026
Geochemists (Patterson) for the 🏆!
010
John Andrew Higgins @blueicedude.bsky.social · 23/04/2026
Princeton is doing the same thing. They just don’t like the bikes!
120
John Andrew Higgins @blueicedude.bsky.social · 22/04/2026
My first NSF rejection of the year! The wheels must be turning! I'll have the chance to apply and get rejected again!
091
John Andrew Higgins @blueicedude.bsky.social · 21/04/2026
There’s only one right answer.
000
John Andrew Higgins @blueicedude.bsky.social · 18/04/2026
Yes we can just do things that make the world better, it doesn’t always have to be CDR.
040
John Andrew Higgins @blueicedude.bsky.social · 17/04/2026
Well 100% of the people I work with don’t know who ICP is!
110
Reposted by John Andrew Higgins
Princeton University @princeton.edu · 06/04/2026
A new agreement between TCNJ and Princeton will allow eligible undergraduate and grad students to enroll in select courses at the other institution during the fall and spring semesters at no additional cost: bit.ly/4tqr2le
TCNJ campusBlair Hall on Princeton's campus
041
Reposted by John Andrew Higgins
Cristi Proistosescu @cristiproist.bsky.social · 18/03/2026
Getting direct measurements of CO2 from Pliocene-aged ice has been a Holy Grail of climate science! A new paper by @jmarkspeterson.bsky.social provides a record of CO2 going back 3million years(!), with (let's say) intriguing implications for anthropogenic climate change doi.org/10.1038/s415... 1/
doi.org
Broadly stable atmospheric CO2 and CH4 levels over the past 3 million years - Nature
Blue ice records from Antarctica are used to determine methane and carbon dioxide concentrations over the past 3 million years.
48530
Reposted by John Andrew Higgins
New Scientist @newscientist.com · 25/03/2026
For the first time, scientists have measured atmospheric gases from the late Pliocene, yielding data that could help to predict the future climate
newscientist.com
Ice core reveals low CO2 during warm spell 3 million years ago
For the first time, scientists have measured atmospheric gases from the late Pliocene, yielding data that could help to predict the future climate
02311
John Andrew Higgins @blueicedude.bsky.social · 26/03/2026
Well it turns out that not so long ago folks tired to model these sorts of things (see below). But somewhere along the way everyone was convinced it was >350 ppm in spite of having no direct records. agupubs.onlinelibrary.wiley.com/doi/full/10....
agupubs.onlinelibrary.wiley.com
A warm Miocene climate at low atmospheric CO2 levels
We simulate a warm climate of the late Miocene at preindustrial CO2 levels The temperature rise is largely due to the late Miocene vegetation distribution Our results support CO2 reconstructions ba...
020
John Andrew Higgins @blueicedude.bsky.social · 26/03/2026
Well let’s dig in shall we?! What are you skeptical about?
000
Reposted by John Andrew Higgins
Thomas Bauska @tinyicybubbles.bsky.social · 24/03/2026
If this is your scene*, maybe this job is for you? Three-year PDRA in ice core gases at @cambridge-earthsci.bsky.social www.cam.ac.uk/jobs/researc... *Scenes from the Beyond EPICA gas analysis in Copenhagen.
1109
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
Agree! It just generally defies my intuition where higher T and higher sea-level = higher CH4 emissions. Maybe that's wrong! or maybe that's true and the story is on the SINK side! Heady days for enthusiasts of the global CH4 cycle.
020
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
I will defer to @cristiproist.bsky.social on that one!
110
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
I don't know! If you've got an idea, let's chat! What I do know is that our models of the CH4 cycle on a warmer Earth ARE PROBABLY WRONG and that we wouldn't know this without paleoclimate DATA. Hooray for DATA! Let's go get more. I know just where to drill.....www.coldex.org
120
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
Or this one. A large part of the higher CH4 levels in these papers is due to enhanced natural terrestrial emissions (wetlands) driven by the warmer/wetter conditions. Our ice cores come from a time that was warmer and sea-level was higher. So why no change in CH4? (3/4) www.pnas.org/doi/10.1073/...
pnas.org
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
120
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
This is super interesting because we really have no way of accurately reconstructing this important greenhouse in the geologic past. Attempts to reconstruct CH4 in the atmosphere using numerical models inevitably get higher levels during past warm periods. See www.pnas.org/doi/10.1073/... (2/4)
pnas.org
Polar amplification of Pliocene climate by elevated trace gas radiative forcing | PNAS
Warm periods in Earth’s history offer opportunities to understand the dynamics of the Earth system under conditions that are similar to those expec...
131
John Andrew Higgins @blueicedude.bsky.social · 24/03/2026
While everyone is (rightly) obsessed with levels of CO2 in the atmosphere 3 million years ago, don't sleep the observation that avg. atmospheric methane (CH4) DOES NOT APPEAR TO HAVE CHANGED AT ALL over the last 3 million years (1/4). www.nature.com/articles/s41...
nature.com
Broadly stable atmospheric CO2 and CH4 levels over the past 3 million years - Nature
Blue ice records from Antarctica are used to determine methane and carbon dioxide concentrations over the past 3 million years.
1134
John Andrew Higgins @blueicedude.bsky.social · 23/03/2026
PS. While I wouldn't say that these lines of evidence are absolutely definitive, they are internally consistent and give us a way to probe this important question going forward. We're also happy to take any suggestions!
130
John Andrew Higgins @blueicedude.bsky.social · 23/03/2026
Third, we try and use estimates of firn thickness from the enrichment in 38Ar relative to 36Ar in trapped air. The lack of change in 38Ar/36Ar at the site (1901) suggests that whatever the climate bias, it has been constant over time (Fig S7, below).
150
John Andrew Higgins @blueicedude.bsky.social · 23/03/2026
Second, we compare ice 400-800 ka that we think integrates over glacial cycles ('long' snapshots) with similarly aged ice from continuous cores (Fig. 1d). The 'long' snapshots are consistent with a slight interglacial bias (see the yellow circle in Fig S6).
120
John Andrew Higgins @blueicedude.bsky.social · 23/03/2026
This is a GREAT question. I'll try to take you through the ways we are thinking about it. First, accumulation rates from the last glacial cycle at a nearby site suggest 10x higher accumulation during warm periods. Even when weighted by duration, this still works out to a (slight) interglacial bias.
120
John Andrew Higgins @blueicedude.bsky.social · 23/03/2026
New results from old ice....happy to answer any questions!
newscientist.com
Ice core reveals low CO2 during warm spell 3 million years ago
For the first time, scientists have measured atmospheric gases from the late Pliocene, yielding data that could help to predict the future climate
45115
John Andrew Higgins @blueicedude.bsky.social · 20/03/2026
Great to have you visit!
010
John Andrew Higgins @blueicedude.bsky.social · 20/03/2026
Truth
010
John Andrew Higgins @blueicedude.bsky.social · 19/03/2026
I very much enjoyed listening to this book. It does a great job capturing the links between CO2, climate, oxygen, plate tectonics, and Earth history which are both simple and incredibly complex! Recommend!
254
John Andrew Higgins @blueicedude.bsky.social · 12/03/2026
Some cool science coming up so I guess it’s time to start posting again?
030
John Andrew Higgins @blueicedude.bsky.social · 24/02/2026
I was wondering where weathering of the oceanic crust fit into the story of everything!
010