Andrew Williams
@andrewilwilliams.bsky.social
Postdoc at UC San Diego | physics of climate 🌤️ 🌍 | PhD Oxford | views my own | he/him
andrewilwilliams.github.io
andrewilwilliams.github.io
Reposted by Andrew Williams
I've seen several Big Climate Accounts™ post about how the recent winter storm was made worse by climate change. It's a convenient narrative.
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
January 31, 2026 at 3:29 AM
I've seen several Big Climate Accounts™ post about how the recent winter storm was made worse by climate change. It's a convenient narrative.
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
This is much more boring in a UK degree (where you don't get much choice):
Classical Mechanics
Symmetry and Relativity
Electromagnetism
Fluid dynamics
Nuclear and particle physics
Classical Mechanics
Symmetry and Relativity
Electromagnetism
Fluid dynamics
Nuclear and particle physics
Five classes I took in college:
Chemistry of the Earth
Mind
Francis Bacon and Legal Reasoning
Science, Culture and Society in Western Civilization
Origin and Evolution of the Solar System
Chemistry of the Earth
Mind
Francis Bacon and Legal Reasoning
Science, Culture and Society in Western Civilization
Origin and Evolution of the Solar System
Tell me five classes you took in college:
Cold War US Foreign Policy
Four Modern Revolutions
The Cryosphere
Antarctic Marine Geology
History of 20th Century Science
Cold War US Foreign Policy
Four Modern Revolutions
The Cryosphere
Antarctic Marine Geology
History of 20th Century Science
January 31, 2026 at 2:48 PM
This is much more boring in a UK degree (where you don't get much choice):
Classical Mechanics
Symmetry and Relativity
Electromagnetism
Fluid dynamics
Nuclear and particle physics
Classical Mechanics
Symmetry and Relativity
Electromagnetism
Fluid dynamics
Nuclear and particle physics
Reposted by Andrew Williams
New planet just dropped and it
1) is almost exactly Earth-sized
2) has a year that's almost exactly 1 Earth year.
3) orbits a star that is not a 💢temperamental little shit M-dwarf 💢but is instead a 🧡 good orange boi 🧡
Me for @science.org based on results presented at #RockyWorlds4: 🔭🧪
1) is almost exactly Earth-sized
2) has a year that's almost exactly 1 Earth year.
3) orbits a star that is not a 💢temperamental little shit M-dwarf 💢but is instead a 🧡 good orange boi 🧡
Me for @science.org based on results presented at #RockyWorlds4: 🔭🧪
Earth-size planet spotted with yearlong orbit
Long-overlooked Kepler signal discovered by citizen scientists reveals promising world worth a closer look
www.science.org
January 28, 2026 at 9:42 PM
New planet just dropped and it
1) is almost exactly Earth-sized
2) has a year that's almost exactly 1 Earth year.
3) orbits a star that is not a 💢temperamental little shit M-dwarf 💢but is instead a 🧡 good orange boi 🧡
Me for @science.org based on results presented at #RockyWorlds4: 🔭🧪
1) is almost exactly Earth-sized
2) has a year that's almost exactly 1 Earth year.
3) orbits a star that is not a 💢temperamental little shit M-dwarf 💢but is instead a 🧡 good orange boi 🧡
Me for @science.org based on results presented at #RockyWorlds4: 🔭🧪
Reposted by Andrew Williams
As the world quickly approaches 1.5C, researchers have a call in Nature to rethink the utility of temperature targets – and to potentially replace them with more actionable and precise targets around clean energy:
As we breach 1.5 °C, we must replace temperature limits with clean-energy targets
Nature - Actionable goals are needed to guide the world towards what needs to happen most quickly: shifting economies to clean energy sources.
www.nature.com
January 27, 2026 at 7:14 PM
As the world quickly approaches 1.5C, researchers have a call in Nature to rethink the utility of temperature targets – and to potentially replace them with more actionable and precise targets around clean energy:
`pip install jcm` :)
Excited that our preprint is out now in GMD!
Excited that our preprint is out now in GMD!
January 27, 2026 at 9:53 PM
`pip install jcm` :)
Excited that our preprint is out now in GMD!
Excited that our preprint is out now in GMD!
Reposted by Andrew Williams
Bridging Physics & AI in Climate Modeling 🌍🤖
Introducing JCM v1.0: A fully differentiable, intermediate-complexity atmospheric model built in Python/JAX.
Training hybrid models is hard because legacy code lacks gradients. JCM solves this.
Introducing JCM v1.0: A fully differentiable, intermediate-complexity atmospheric model built in Python/JAX.
Training hybrid models is hard because legacy code lacks gradients. JCM solves this.
January 26, 2026 at 10:30 PM
Bridging Physics & AI in Climate Modeling 🌍🤖
Introducing JCM v1.0: A fully differentiable, intermediate-complexity atmospheric model built in Python/JAX.
Training hybrid models is hard because legacy code lacks gradients. JCM solves this.
Introducing JCM v1.0: A fully differentiable, intermediate-complexity atmospheric model built in Python/JAX.
Training hybrid models is hard because legacy code lacks gradients. JCM solves this.
Reposted by Andrew Williams
The risks of AI in schools outweigh the benefits.
AI poses a grave threat to students' cognitive development.
www.npr.org/2026/01/14/n...
AI poses a grave threat to students' cognitive development.
www.npr.org/2026/01/14/n...
The risks of AI in schools outweigh the benefits, report says
A new report warns that AI poses a serious threat to children's cognitive development and emotional well-being.
www.npr.org
January 14, 2026 at 11:09 PM
The risks of AI in schools outweigh the benefits.
AI poses a grave threat to students' cognitive development.
www.npr.org/2026/01/14/n...
AI poses a grave threat to students' cognitive development.
www.npr.org/2026/01/14/n...
Reposted by Andrew Williams
Convection ≠ Overturning: Why Labrador Sea convection doesn’t drive the AMOC: A simple explanation 🌊🧪 ocean2climate.org/2026/01/10/w...
Why Labrador Sea Convection Doesn’t Drive The AMOC: A Simple Explanation
The oceanography community is deeply engaged in a debate about how much weight the Labrador Sea actually carries in maintaining the Atlantic Overturning Circulation (AMOC) system. According to the …
ocean2climate.org
January 10, 2026 at 5:36 PM
Convection ≠ Overturning: Why Labrador Sea convection doesn’t drive the AMOC: A simple explanation 🌊🧪 ocean2climate.org/2026/01/10/w...
Reposted by Andrew Williams
Homeland Security’s description of what happened and the narrative they’re pushing clearly doesn’t match up with the videos we’re all seeing.
They’re asking people not to believe what we can all see with our own eyes.
I’ve been in contact with DHS demanding more information.
They’re asking people not to believe what we can all see with our own eyes.
I’ve been in contact with DHS demanding more information.
January 7, 2026 at 9:18 PM
Homeland Security’s description of what happened and the narrative they’re pushing clearly doesn’t match up with the videos we’re all seeing.
They’re asking people not to believe what we can all see with our own eyes.
I’ve been in contact with DHS demanding more information.
They’re asking people not to believe what we can all see with our own eyes.
I’ve been in contact with DHS demanding more information.
Reposted by Andrew Williams
Tropical Temperature Distributions Over a Wide Range of Climates 🌡️🥵
Using theory + sims, we explore how temperature PDFs respond to climate change over land vs ocean. Work led by Josh Duffield! @earthscista.bsky.social @uniofstandrews.bsky.social @ametsoc.org
journals.ametsoc.org/view/journal...
Using theory + sims, we explore how temperature PDFs respond to climate change over land vs ocean. Work led by Josh Duffield! @earthscista.bsky.social @uniofstandrews.bsky.social @ametsoc.org
journals.ametsoc.org/view/journal...
January 6, 2026 at 4:06 PM
Tropical Temperature Distributions Over a Wide Range of Climates 🌡️🥵
Using theory + sims, we explore how temperature PDFs respond to climate change over land vs ocean. Work led by Josh Duffield! @earthscista.bsky.social @uniofstandrews.bsky.social @ametsoc.org
journals.ametsoc.org/view/journal...
Using theory + sims, we explore how temperature PDFs respond to climate change over land vs ocean. Work led by Josh Duffield! @earthscista.bsky.social @uniofstandrews.bsky.social @ametsoc.org
journals.ametsoc.org/view/journal...
Starting 2026 with a bang, our paper is published! 🎉🎉🎉
In it, we explored how polar amplification depends on the underlying climate state, with implications for understanding the past and future evolution of polar climate change!
Enjoy! :)
agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL118423
In it, we explored how polar amplification depends on the underlying climate state, with implications for understanding the past and future evolution of polar climate change!
Enjoy! :)
agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL118423
January 6, 2026 at 3:25 PM
Starting 2026 with a bang, our paper is published! 🎉🎉🎉
In it, we explored how polar amplification depends on the underlying climate state, with implications for understanding the past and future evolution of polar climate change!
Enjoy! :)
agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL118423
In it, we explored how polar amplification depends on the underlying climate state, with implications for understanding the past and future evolution of polar climate change!
Enjoy! :)
agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL118423
Reposted by Andrew Williams
And speaking of future heatwaves.
New paper alert! A tour de force by my (now former) PhD student Adam Bauer.
We introduce SMACM (Soil Moisture Atmosphere Coupled Model): a simple(ish) nonlinear Hasselman model to explain the non-linear relationship between temperature and soil moisture.
New paper alert! A tour de force by my (now former) PhD student Adam Bauer.
We introduce SMACM (Soil Moisture Atmosphere Coupled Model): a simple(ish) nonlinear Hasselman model to explain the non-linear relationship between temperature and soil moisture.
doi.org
January 5, 2026 at 5:50 PM
And speaking of future heatwaves.
New paper alert! A tour de force by my (now former) PhD student Adam Bauer.
We introduce SMACM (Soil Moisture Atmosphere Coupled Model): a simple(ish) nonlinear Hasselman model to explain the non-linear relationship between temperature and soil moisture.
New paper alert! A tour de force by my (now former) PhD student Adam Bauer.
We introduce SMACM (Soil Moisture Atmosphere Coupled Model): a simple(ish) nonlinear Hasselman model to explain the non-linear relationship between temperature and soil moisture.
Reposted by Andrew Williams
Really enjoying reading the biography of Crick by @matthewcobb.bsky.social. Got me thinking about archives and collecting an archive of the International Detection and Attribution Group (see my book Hot Air). Here are four key members - Wehner, Allen, Hegerl, Tett at an IDAG meeting in the 1990s.
January 4, 2026 at 7:10 PM
Really enjoying reading the biography of Crick by @matthewcobb.bsky.social. Got me thinking about archives and collecting an archive of the International Detection and Attribution Group (see my book Hot Air). Here are four key members - Wehner, Allen, Hegerl, Tett at an IDAG meeting in the 1990s.
Reposted by Andrew Williams
Reposted by Andrew Williams
2025 goes down as the ~3rd-warmest year on record (based on ERA5).
Like in 2024, every single day this past year was warmer than the average of even the most recent reference period (1991-2020).
Like in 2024, every single day this past year was warmer than the average of even the most recent reference period (1991-2020).
January 4, 2026 at 5:38 PM
2025 goes down as the ~3rd-warmest year on record (based on ERA5).
Like in 2024, every single day this past year was warmer than the average of even the most recent reference period (1991-2020).
Like in 2024, every single day this past year was warmer than the average of even the most recent reference period (1991-2020).
Reposted by Andrew Williams
#NCAR is a beautiful place and a national treasure. I had the chance to visit the NCAR Mesa Lab last summer, and their exhibits (free and public) are the coolest and most informative ones I’ve seen on atmospheric and climate science. (1/3)
December 18, 2025 at 11:10 PM
#NCAR is a beautiful place and a national treasure. I had the chance to visit the NCAR Mesa Lab last summer, and their exhibits (free and public) are the coolest and most informative ones I’ve seen on atmospheric and climate science. (1/3)
Reposted by Andrew Williams
Some reflections after returning back from a conference at which I and 20,000 colleagues learned that the Trump administration intends to dismantle #NCAR. This outrage should not happen. deepconvection.substack.com/p/save-ncar
Save NCAR
Field notes from New Orleans, where I and 20,000 colleagues learned that Trump intends to destroy the National Center for Atmospheric Research.
deepconvection.substack.com
December 21, 2025 at 7:25 PM
Some reflections after returning back from a conference at which I and 20,000 colleagues learned that the Trump administration intends to dismantle #NCAR. This outrage should not happen. deepconvection.substack.com/p/save-ncar
Reposted by Andrew Williams
NOAA has started terminating grants to UCAR under the UCAR/NOAA Climate Adaptation and Mitigation Program (CAMP).
December 21, 2025 at 2:31 AM
NOAA has started terminating grants to UCAR under the UCAR/NOAA Climate Adaptation and Mitigation Program (CAMP).
Reposted by Andrew Williams
Closing out my year with a journal editor shocker 🧵
Checking new manuscripts today I reviewed a paper attributing 2 papers to me I did not write. A daft thing for an author to do of course. But intrigued I web searched up one of the titles and that's when it got real weird...
Checking new manuscripts today I reviewed a paper attributing 2 papers to me I did not write. A daft thing for an author to do of course. But intrigued I web searched up one of the titles and that's when it got real weird...
December 19, 2025 at 5:20 PM
Closing out my year with a journal editor shocker 🧵
Checking new manuscripts today I reviewed a paper attributing 2 papers to me I did not write. A daft thing for an author to do of course. But intrigued I web searched up one of the titles and that's when it got real weird...
Checking new manuscripts today I reviewed a paper attributing 2 papers to me I did not write. A daft thing for an author to do of course. But intrigued I web searched up one of the titles and that's when it got real weird...
Reposted by Andrew Williams
Awesome turnout in support of @ncar-ucar.bsky.social at #AGU25. Take a look at how many people use our products!
December 18, 2025 at 7:35 PM
Awesome turnout in support of @ncar-ucar.bsky.social at #AGU25. Take a look at how many people use our products!
Reposted by Andrew Williams
Join us for a critical conversation on the future of U.S. atmospheric science.
UCAR President Antonio Busalacchi hosts this town hall on what’s at stake if NSF NCAR is dismantled.
buff.ly/jR6tGwo
UCAR President Antonio Busalacchi hosts this town hall on what’s at stake if NSF NCAR is dismantled.
buff.ly/jR6tGwo
December 18, 2025 at 3:17 PM
Join us for a critical conversation on the future of U.S. atmospheric science.
UCAR President Antonio Busalacchi hosts this town hall on what’s at stake if NSF NCAR is dismantled.
buff.ly/jR6tGwo
UCAR President Antonio Busalacchi hosts this town hall on what’s at stake if NSF NCAR is dismantled.
buff.ly/jR6tGwo
Reposted by Andrew Williams
Reposted by Andrew Williams
I came to the US over 10 years ago for a postdoc at NCAR. It changed my life and supercharged my ability to do science. NCAR's unique community nature makes it a global node in atmospheric and climate research. It's really not possible to overstate its value for science and society.
December 17, 2025 at 1:55 PM
I came to the US over 10 years ago for a postdoc at NCAR. It changed my life and supercharged my ability to do science. NCAR's unique community nature makes it a global node in atmospheric and climate research. It's really not possible to overstate its value for science and society.