Ken Caldeira
@kencaldeira.com
Mostly mentoring a group of postdocs at Stanford.
Senior Scientist at Gates Ventures.
climate / energy / etc
https://sustainablesolutions.stanford.edu/people/ken-caldeira
Posts imperfectly represent the views of my former self and not my employer.
Senior Scientist at Gates Ventures.
climate / energy / etc
https://sustainablesolutions.stanford.edu/people/ken-caldeira
Posts imperfectly represent the views of my former self and not my employer.
Pinned
Ken Caldeira
@kencaldeira.com
· Nov 18
Folks, I am really appreciative of people who have followed me and added me to their starter packs.
I post about climate science, energy system transition, and related issues.
I try to restrain myself to information and questions, and try to avoid unseemly opining in public.
I post about climate science, energy system transition, and related issues.
I try to restrain myself to information and questions, and try to avoid unseemly opining in public.
In a world where nothing the Republicans do seems shocking anymore, the ascension of Emil Bove to the 3rd circuit is one of the most egregiously repugnant acts by Senate Republicans.
www.politico.com/live-updates...
www.politico.com/live-updates...
Judiciary Democrats demand probe after third Bove whistleblower
The top Justice Department official is set to be confirmed as a federal appeals judge this week.
www.politico.com
January 15, 2026 at 8:40 PM
In a world where nothing the Republicans do seems shocking anymore, the ascension of Emil Bove to the 3rd circuit is one of the most egregiously repugnant acts by Senate Republicans.
www.politico.com/live-updates...
www.politico.com/live-updates...
Reposted by Ken Caldeira
The import of this ruling: Foreign citizens in the United States—including green card holders—can be arrested for political speech and imprisoned for months or even years before being given a meaningful opportunity to challenge the constitutionality of their arrest and imprisonment.
Appeals Court Opens the Door to Mahmoud Khalil’s Rearrest
www.nytimes.com
January 15, 2026 at 4:00 PM
The import of this ruling: Foreign citizens in the United States—including green card holders—can be arrested for political speech and imprisoned for months or even years before being given a meaningful opportunity to challenge the constitutionality of their arrest and imprisonment.
correlation = causation ?
January 15, 2026 at 8:28 PM
correlation = causation ?
Reposted by Ken Caldeira
BREAKING via NYT
FBI agents searched the home of a Washington Post reporter on Wednesday as part of an investigation into the possible sharing of government secrets.
Searches of a reporter’s home are extremely rare, even in investigations involving classified docs.
Full Story: bit.ly/4jIxUHd
FBI agents searched the home of a Washington Post reporter on Wednesday as part of an investigation into the possible sharing of government secrets.
Searches of a reporter’s home are extremely rare, even in investigations involving classified docs.
Full Story: bit.ly/4jIxUHd
January 14, 2026 at 2:21 PM
BREAKING via NYT
FBI agents searched the home of a Washington Post reporter on Wednesday as part of an investigation into the possible sharing of government secrets.
Searches of a reporter’s home are extremely rare, even in investigations involving classified docs.
Full Story: bit.ly/4jIxUHd
FBI agents searched the home of a Washington Post reporter on Wednesday as part of an investigation into the possible sharing of government secrets.
Searches of a reporter’s home are extremely rare, even in investigations involving classified docs.
Full Story: bit.ly/4jIxUHd
Reposted by Ken Caldeira
The Congressional Progressive Caucus, a group of nearly 100 House Democrats, will announce later today that it's formally endorsing legislation to strip $175 billion from ICE and put it toward affordable housing. www.huffpost.com/entry/doj-fe...
Progressive Caucus Backs Bill To Redirect ICE Money To Affordable Housing
www.huffpost.com
January 14, 2026 at 8:00 PM
The Congressional Progressive Caucus, a group of nearly 100 House Democrats, will announce later today that it's formally endorsing legislation to strip $175 billion from ICE and put it toward affordable housing. www.huffpost.com/entry/doj-fe...
Unless someone is an extremely powerful public figure (e.g., Donald Trump), there are basically two (or three?) acceptable replies to someone's social media post:
1. Praise
2. Ask a question
3. Judiciously provide additional relevant information (?)
(You can consider this one "praise".)
1. Praise
2. Ask a question
3. Judiciously provide additional relevant information (?)
(You can consider this one "praise".)
January 14, 2026 at 9:01 PM
Unless someone is an extremely powerful public figure (e.g., Donald Trump), there are basically two (or three?) acceptable replies to someone's social media post:
1. Praise
2. Ask a question
3. Judiciously provide additional relevant information (?)
(You can consider this one "praise".)
1. Praise
2. Ask a question
3. Judiciously provide additional relevant information (?)
(You can consider this one "praise".)
One can imagine that the optimum would be to divide states into what are now House districts, so each district would be like Wyoming with one Representative and two Senators.
One need not go that far, and could lump regions something like this. (Not sure of D vs R implications, however.)
One need not go that far, and could lump regions something like this. (Not sure of D vs R implications, however.)
January 14, 2026 at 8:52 PM
One can imagine that the optimum would be to divide states into what are now House districts, so each district would be like Wyoming with one Representative and two Senators.
One need not go that far, and could lump regions something like this. (Not sure of D vs R implications, however.)
One need not go that far, and could lump regions something like this. (Not sure of D vs R implications, however.)
To the extent that the large states are subdivided into states of equal population, rather than equal area, it should be helpful.
January 14, 2026 at 8:46 PM
To the extent that the large states are subdivided into states of equal population, rather than equal area, it should be helpful.
This would require approval of the state legislature, and a simple majority of the House and Senate, with Presidential signature.
constitution.congress.gov/browse/artic...
(2/2)
constitution.congress.gov/browse/artic...
(2/2)
January 14, 2026 at 7:21 PM
This would require approval of the state legislature, and a simple majority of the House and Senate, with Presidential signature.
constitution.congress.gov/browse/artic...
(2/2)
constitution.congress.gov/browse/artic...
(2/2)
Wyoming has 67 times as many Senators, and 3.7 times as many electoral votes, per capita compared to California.
The next time the Democrats have a trifecta, they should divide every large blue state into as many tiny little blue states as possible.
(1/2)
The next time the Democrats have a trifecta, they should divide every large blue state into as many tiny little blue states as possible.
(1/2)
January 14, 2026 at 7:19 PM
Wyoming has 67 times as many Senators, and 3.7 times as many electoral votes, per capita compared to California.
The next time the Democrats have a trifecta, they should divide every large blue state into as many tiny little blue states as possible.
(1/2)
The next time the Democrats have a trifecta, they should divide every large blue state into as many tiny little blue states as possible.
(1/2)
An implication of this chart is that ~55% of the population are Dem's or Dem-leaning, and 45% are Rep's or Rep-leaning.
If we had one-person/one-vote (reformed Electoral College and Senate), we would not be suffering under the Republican fascist regime.
If we had one-person/one-vote (reformed Electoral College and Senate), we would not be suffering under the Republican fascist regime.
January 14, 2026 at 6:33 PM
An implication of this chart is that ~55% of the population are Dem's or Dem-leaning, and 45% are Rep's or Rep-leaning.
If we had one-person/one-vote (reformed Electoral College and Senate), we would not be suffering under the Republican fascist regime.
If we had one-person/one-vote (reformed Electoral College and Senate), we would not be suffering under the Republican fascist regime.
Reposted by Ken Caldeira
"“They specifically asked me if I knew where the Hmong families lived on my street & in the neighborhood.” Lugert-Thom responded, “I don’t know anything about that” & she said they then asked, “Well, what about the Asian families?”"
"“I was a bit shaken & a bit shocked of what I was asked to do.”"
"“I was a bit shaken & a bit shocked of what I was asked to do.”"
A St. Paul resident says federal officers knocked on her door and asked her to identify Hmong and Asian households in her North End neighborhood last week.
ICE in St. Paul: Man roughly detained at gas station, Border Patrol chief jeered in Midway Target
Videos and photos show a prevalence of federal agents in St. Paul recently.
trib.al
January 13, 2026 at 10:37 PM
"“They specifically asked me if I knew where the Hmong families lived on my street & in the neighborhood.” Lugert-Thom responded, “I don’t know anything about that” & she said they then asked, “Well, what about the Asian families?”"
"“I was a bit shaken & a bit shocked of what I was asked to do.”"
"“I was a bit shaken & a bit shocked of what I was asked to do.”"
Right now is a good time to remind ourselves about George Saunders wise and superb 2013 graduation speech at Syracuse University:
"What I regret most in my life are failures of kindness."
archive.nytimes.com/6thfloor.blo...
"What I regret most in my life are failures of kindness."
archive.nytimes.com/6thfloor.blo...
January 14, 2026 at 5:34 PM
Right now is a good time to remind ourselves about George Saunders wise and superb 2013 graduation speech at Syracuse University:
"What I regret most in my life are failures of kindness."
archive.nytimes.com/6thfloor.blo...
"What I regret most in my life are failures of kindness."
archive.nytimes.com/6thfloor.blo...
Reposted by Ken Caldeira
Globally, no single day in 2025 was cooler than its 1991-2020 average.
climate.copernicus.eu/global-clima...
climate.copernicus.eu/global-clima...
January 14, 2026 at 12:44 PM
Globally, no single day in 2025 was cooler than its 1991-2020 average.
climate.copernicus.eu/global-clima...
climate.copernicus.eu/global-clima...
Reposted by Ken Caldeira
A protester is currently lying in a hospital bed with a piece of shrapnel in his neck 7mm from his carotid artery.
While he lay bleeding on the pavement, blinded in his left eye, gasping for air, agents did not call a medic. They dragged him and sneered: "You're going to lose your eye."
While he lay bleeding on the pavement, blinded in his left eye, gasping for air, agents did not call a medic. They dragged him and sneered: "You're going to lose your eye."
January 14, 2026 at 4:43 AM
A protester is currently lying in a hospital bed with a piece of shrapnel in his neck 7mm from his carotid artery.
While he lay bleeding on the pavement, blinded in his left eye, gasping for air, agents did not call a medic. They dragged him and sneered: "You're going to lose your eye."
While he lay bleeding on the pavement, blinded in his left eye, gasping for air, agents did not call a medic. They dragged him and sneered: "You're going to lose your eye."
Free speech absolutists
January 14, 2026 at 3:30 AM
Free speech absolutists
January 13, 2026 at 10:01 PM
What are fossil fuels other than stored solar power?
January 13, 2026 at 7:03 PM
What are fossil fuels other than stored solar power?
"Trump says killers of protesters will ‘pay a big price’", unless the killers of protesters happen to be ICE agents and the victims our political opposition.
www.theguardian.com/world/live/2...
www.theguardian.com/world/live/2...
Iran crisis live: Trump says killers of protesters will ‘pay a big price’ and urges Iranians to ‘take over your institutions’
US president cancels meetings with Iranian officials ‘until senseless killing of protesters stops’
www.theguardian.com
January 13, 2026 at 6:01 PM
"Trump says killers of protesters will ‘pay a big price’", unless the killers of protesters happen to be ICE agents and the victims our political opposition.
www.theguardian.com/world/live/2...
www.theguardian.com/world/live/2...
Honest civil servants are the unsung heroes of what is left of our government.
www.nytimes.com/2026/01/13/u...
www.nytimes.com/2026/01/13/u...
3 Prosecutors Quit After Push to Investigate ICE Shooting Victim’s Widow
www.nytimes.com
January 13, 2026 at 5:56 PM
Honest civil servants are the unsung heroes of what is left of our government.
www.nytimes.com/2026/01/13/u...
www.nytimes.com/2026/01/13/u...
These people are unhinged.
They need professional psychological care.
They should not be in positions of power.
They need professional psychological care.
They should not be in positions of power.
January 13, 2026 at 5:11 PM
These people are unhinged.
They need professional psychological care.
They should not be in positions of power.
They need professional psychological care.
They should not be in positions of power.
"Over the long lifetime of CO2 in the atmosphere, the cumulative CO2-radiative forcing exceeds the amount of energy released upon combustion by a factor >100,000."
agupubs.onlinelibrary.wiley.com/doi/10.1002/...
Pan et al's excellent new study reminded me of our 2015 study.
agupubs.onlinelibrary.wiley.com/doi/10.1002/...
Pan et al's excellent new study reminded me of our 2015 study.
January 13, 2026 at 5:10 PM
"Over the long lifetime of CO2 in the atmosphere, the cumulative CO2-radiative forcing exceeds the amount of energy released upon combustion by a factor >100,000."
agupubs.onlinelibrary.wiley.com/doi/10.1002/...
Pan et al's excellent new study reminded me of our 2015 study.
agupubs.onlinelibrary.wiley.com/doi/10.1002/...
Pan et al's excellent new study reminded me of our 2015 study.
Friends were in discussion with a company, with the aim of building a mechanistic world model that would be controlled by an LLM, and thus give continuity to long-form videos.
I think we will see a lot more of this merger between LLMs and deterministic computation.
I think we will see a lot more of this merger between LLMs and deterministic computation.
January 13, 2026 at 5:01 PM
Friends were in discussion with a company, with the aim of building a mechanistic world model that would be controlled by an LLM, and thus give continuity to long-form videos.
I think we will see a lot more of this merger between LLMs and deterministic computation.
I think we will see a lot more of this merger between LLMs and deterministic computation.
In a number of domains, computer scientists are taking hybrid approaches, combining an LLM with a deterministic solver like SymPy or Mathematica.
January 13, 2026 at 5:00 PM
In a number of domains, computer scientists are taking hybrid approaches, combining an LLM with a deterministic solver like SymPy or Mathematica.
I find LLM's really great at a lot of symbolic mathematics, replacing a lot of my use of Mathematica.
Instead of applying a bunch of deterministic transformation rules, it finds correlations involving previously solved problems.
Of course, error checking is essential because LLMs make mistakes.
Instead of applying a bunch of deterministic transformation rules, it finds correlations involving previously solved problems.
Of course, error checking is essential because LLMs make mistakes.
January 13, 2026 at 4:59 PM
I find LLM's really great at a lot of symbolic mathematics, replacing a lot of my use of Mathematica.
Instead of applying a bunch of deterministic transformation rules, it finds correlations involving previously solved problems.
Of course, error checking is essential because LLMs make mistakes.
Instead of applying a bunch of deterministic transformation rules, it finds correlations involving previously solved problems.
Of course, error checking is essential because LLMs make mistakes.