Karl Mathiesen
@karlmathiesen.bsky.social
Senior Climate Correspondent at POLITICO
Pinned
The Strange and Totally Real Plan to Blot Out the Sun and Reverse Global Warming
A 25-person startup is developing technology to block the sun and turn down the planet’s thermostat. The stakes are huge — and the company and its critics say regulations need to catch up.
www.politico.com
Stardust. The Israeli-U.S. company with a strange and totally real plan to block out the sun and reverse global warming.
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
Stardust. The Israeli-U.S. company with a strange and totally real plan to block out the sun and reverse global warming.
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
The Strange and Totally Real Plan to Blot Out the Sun and Reverse Global Warming
A 25-person startup is developing technology to block the sun and turn down the planet’s thermostat. The stakes are huge — and the company and its critics say regulations need to catch up.
www.politico.com
November 23, 2025 at 2:28 PM
Stardust. The Israeli-U.S. company with a strange and totally real plan to block out the sun and reverse global warming.
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
Reporting this story involved a complete relearning of what I thought I knew about the climate future.
w/@corbinhiar.bsky.social
www.politico.com/news/magazin...
NEW: Climate summit proposal dodges call to accelerate move from fossil fuels
www.politico.com/news/2025/11...
www.politico.com/news/2025/11...
Climate summit proposal dodges call to accelerate move from fossil fuels
The final text of a proposed deal would be a disappointment for European countries and low-lying Pacific island nations.
www.politico.com
November 22, 2025 at 12:23 PM
NEW: Climate summit proposal dodges call to accelerate move from fossil fuels
www.politico.com/news/2025/11...
www.politico.com/news/2025/11...
🚨'The worst environmental setback in Brazil's history.'
Just a week after COP30 ends, it looks almost certain that Brazil's agribusiness dominated Congress will strip almost all oversight of damaging projects.
My report from Brasília.
www.politico.eu/article/braz...
Just a week after COP30 ends, it looks almost certain that Brazil's agribusiness dominated Congress will strip almost all oversight of damaging projects.
My report from Brasília.
www.politico.eu/article/braz...
Brazilian lawmakers seek to decimate green laws one week after hosting climate summit
Changes would damage President Lula’s efforts to cast Brazil as an environmental leader.
www.politico.eu
November 17, 2025 at 10:14 AM
🚨'The worst environmental setback in Brazil's history.'
Just a week after COP30 ends, it looks almost certain that Brazil's agribusiness dominated Congress will strip almost all oversight of damaging projects.
My report from Brasília.
www.politico.eu/article/braz...
Just a week after COP30 ends, it looks almost certain that Brazil's agribusiness dominated Congress will strip almost all oversight of damaging projects.
My report from Brasília.
www.politico.eu/article/braz...
NEW: Geoengineering startup Stardust Solutions has been secretly lobbying Congress for months
w/ @corbinhiar.bsky.social
subscriber.politicopro.com/article/eene...
w/ @corbinhiar.bsky.social
subscriber.politicopro.com/article/eene...
E&E News: Geoengineering startup has been secretly lobbying Congress for months
Stardust Solutions hired Holland & Knight, but the lobbying giant says it "inadvertently" failed to publicly disclose its work for the startup, as required by law.
subscriber.politicopro.com
November 5, 2025 at 2:34 PM
NEW: Geoengineering startup Stardust Solutions has been secretly lobbying Congress for months
w/ @corbinhiar.bsky.social
subscriber.politicopro.com/article/eene...
w/ @corbinhiar.bsky.social
subscriber.politicopro.com/article/eene...
Reposted by Karl Mathiesen
Stardust's new investors include the billionaire Chris Sacca and the Agnelli family, an Italian industrial dynasty.
The startup plans to spend the cash on "controlled outdoor experiments," the CEO says.
But critics remain skeptical of its business plan: "I don't think that is, at all, reasonable."
The startup plans to spend the cash on "controlled outdoor experiments," the CEO says.
But critics remain skeptical of its business plan: "I don't think that is, at all, reasonable."
A once-outlandish idea for reversing global warming takes a major step toward reality.
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
Israeli-American global cooling startup raises $60M to test sun-reflecting technology
The fundraising haul marks strong enthusiasm for experiments aimed at lowering temperatures, said the company. But it also raises questions about commercializing technologies with potentially damag…
www.politico.eu
October 24, 2025 at 1:39 PM
Stardust's new investors include the billionaire Chris Sacca and the Agnelli family, an Italian industrial dynasty.
The startup plans to spend the cash on "controlled outdoor experiments," the CEO says.
But critics remain skeptical of its business plan: "I don't think that is, at all, reasonable."
The startup plans to spend the cash on "controlled outdoor experiments," the CEO says.
But critics remain skeptical of its business plan: "I don't think that is, at all, reasonable."
A once-outlandish idea for reversing global warming takes a major step toward reality.
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
Israeli-American global cooling startup raises $60M to test sun-reflecting technology
The fundraising haul marks strong enthusiasm for experiments aimed at lowering temperatures, said the company. But it also raises questions about commercializing technologies with potentially damag…
www.politico.eu
October 24, 2025 at 12:56 PM
A once-outlandish idea for reversing global warming takes a major step toward reality.
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
w/ @corbinhiar.bsky.social
www.politico.eu/article/glob...
"Some were left wondering what Hoekstra hoped to achieve when he attacked Beijing for a “clearly disappointing” climate plan — especially after the EU had failed to present its own strategy."
w. @l-guillot.bsky.social and @marieccles.bsky.social
www.politico.eu/article/wopk...
w. @l-guillot.bsky.social and @marieccles.bsky.social
www.politico.eu/article/wopk...
Hoekstra’s mano a mano with China wobbles climate summit
EU’s top climate envoy’s war of words sparks fears of diplomatic discord ahead of COP30.
www.politico.eu
October 13, 2025 at 11:10 AM
"Some were left wondering what Hoekstra hoped to achieve when he attacked Beijing for a “clearly disappointing” climate plan — especially after the EU had failed to present its own strategy."
w. @l-guillot.bsky.social and @marieccles.bsky.social
www.politico.eu/article/wopk...
w. @l-guillot.bsky.social and @marieccles.bsky.social
www.politico.eu/article/wopk...
A question I thought it would be easier to find the answer to than it is. Can any climate scientists on here tell me how to calculate how much excess CO2 there is in the atmosphere now as opposed to pre-industrial levels? ie 280ppm vs 425ppm expressed as tons?
October 6, 2025 at 9:49 AM
A question I thought it would be easier to find the answer to than it is. Can any climate scientists on here tell me how to calculate how much excess CO2 there is in the atmosphere now as opposed to pre-industrial levels? ie 280ppm vs 425ppm expressed as tons?
After Environment Commissioner Roswall delays EU forest law blaming IT issues, the Commission's VP Teresa Ribera tells us she's really not convinced.
“There may be [IT problems] — I don't know."
"I think that it is very controversial to give it up."
www.politico.eu/article/euro...
“There may be [IT problems] — I don't know."
"I think that it is very controversial to give it up."
www.politico.eu/article/euro...
Don’t abandon forest law over IT problem, Ribera urges Commission
Vice president of the EU executive says computer issues not good enough reason to further delay anti-deforestation law.
www.politico.eu
September 29, 2025 at 8:41 AM
After Environment Commissioner Roswall delays EU forest law blaming IT issues, the Commission's VP Teresa Ribera tells us she's really not convinced.
“There may be [IT problems] — I don't know."
"I think that it is very controversial to give it up."
www.politico.eu/article/euro...
“There may be [IT problems] — I don't know."
"I think that it is very controversial to give it up."
www.politico.eu/article/euro...
“Many in China now characterize the EU as a middle power."
How Europe sabotaged it's place at the head of the climate pack.
With @ziaweise.bsky.social and @saraschonhardt.bsky.social
www.politico.eu/article/euro...
How Europe sabotaged it's place at the head of the climate pack.
With @ziaweise.bsky.social and @saraschonhardt.bsky.social
www.politico.eu/article/euro...
Europe’s climate clout melts away
China stands ready to fill the gap as EU infighting leaves a vacuum in global climate talks.
www.politico.eu
September 24, 2025 at 9:15 AM
“Many in China now characterize the EU as a middle power."
How Europe sabotaged it's place at the head of the climate pack.
With @ziaweise.bsky.social and @saraschonhardt.bsky.social
www.politico.eu/article/euro...
How Europe sabotaged it's place at the head of the climate pack.
With @ziaweise.bsky.social and @saraschonhardt.bsky.social
www.politico.eu/article/euro...
“If policymakers fail to act, they risk fueling the very populism they claim to fear.”
@thisisbartosz.bsky.social scoops an unvarnished view of the EU's climate backtracking from Connie Hedegaard.
www.politico.eu/article/gree...
@thisisbartosz.bsky.social scoops an unvarnished view of the EU's climate backtracking from Connie Hedegaard.
www.politico.eu/article/gree...
‘They should be ashamed’: Green backsliding is wrecking Europe, EU’s first climate chief warns
From wildfires to far-right gains, Connie Hedegaard says Europe can’t afford to go soft on climate while China races ahead and companies like BP backtrack.
www.politico.eu
August 21, 2025 at 12:32 PM
“If policymakers fail to act, they risk fueling the very populism they claim to fear.”
@thisisbartosz.bsky.social scoops an unvarnished view of the EU's climate backtracking from Connie Hedegaard.
www.politico.eu/article/gree...
@thisisbartosz.bsky.social scoops an unvarnished view of the EU's climate backtracking from Connie Hedegaard.
www.politico.eu/article/gree...
NEW: Saudi Aramco employee named lead author of global climate report
www.politico.eu/article/saud...
www.politico.eu/article/saud...
Saudi Aramco employee named lead author of global climate report
Mustafa Babiker was proposed for the key role last month.
www.politico.eu
August 19, 2025 at 9:55 AM
NEW: Saudi Aramco employee named lead author of global climate report
www.politico.eu/article/saud...
www.politico.eu/article/saud...
August 4, 2025 at 2:44 PM
NEW: Backroom deals, embassy contacts and brown liquor built a booming trade of American LNG to Europe.
Now, the lobbyist who saw it all says the U.S. president’s dalliances with Vladimir Putin are an incoming “asteroid” for the industry.
www.politico.eu/article/euro...
Now, the lobbyist who saw it all says the U.S. president’s dalliances with Vladimir Putin are an incoming “asteroid” for the industry.
www.politico.eu/article/euro...
Europe learned to love American gas. This is how Trump wrecks it.
Backroom deals, embassy contacts and brown liquor built a booming export trade. Now, the lobbyist who saw it all says the U.S. president’s dalliances with Vladimir Putin are an incoming “aste…
www.politico.eu
July 31, 2025 at 11:40 AM
NEW: Backroom deals, embassy contacts and brown liquor built a booming trade of American LNG to Europe.
Now, the lobbyist who saw it all says the U.S. president’s dalliances with Vladimir Putin are an incoming “asteroid” for the industry.
www.politico.eu/article/euro...
Now, the lobbyist who saw it all says the U.S. president’s dalliances with Vladimir Putin are an incoming “asteroid” for the industry.
www.politico.eu/article/euro...
‘She’s pretty much alone’: The EU’s greenest leader fights the tide
Teresa Ribera, the EU's 2nd in charge, has won significant victories in secret against a combination of attacks and disinterest.
w/ @ziaweise.bsky.social
www.politico.eu/article/tere...
Teresa Ribera, the EU's 2nd in charge, has won significant victories in secret against a combination of attacks and disinterest.
w/ @ziaweise.bsky.social
www.politico.eu/article/tere...
‘She’s pretty much alone’: The EU’s greenest leader fights the tide
The European Commission’s second-most powerful politician is isolated, beleaguered and under attack — just like the green policy she has vowed to protect.
www.politico.eu
July 3, 2025 at 11:05 AM
‘She’s pretty much alone’: The EU’s greenest leader fights the tide
Teresa Ribera, the EU's 2nd in charge, has won significant victories in secret against a combination of attacks and disinterest.
w/ @ziaweise.bsky.social
www.politico.eu/article/tere...
Teresa Ribera, the EU's 2nd in charge, has won significant victories in secret against a combination of attacks and disinterest.
w/ @ziaweise.bsky.social
www.politico.eu/article/tere...
NEW: Sudanese economist Mustafa Babiker — a long-term employee of the Saudi Aramco oil company — has been proposed as coordinating lead author of a crucial chapter of the next UN climate science report, a leaked document shows.
www.politico.eu/article/saud...
www.politico.eu/article/saud...
Global climate science body roiled by controversies stoked by Saudis, US
The proposed selection of a Saudi Aramco oil company staffer as one of the authors of a key science report has been denounced as “political capture.”
www.politico.eu
July 1, 2025 at 5:35 AM
NEW: Sudanese economist Mustafa Babiker — a long-term employee of the Saudi Aramco oil company — has been proposed as coordinating lead author of a crucial chapter of the next UN climate science report, a leaked document shows.
www.politico.eu/article/saud...
www.politico.eu/article/saud...
🇪🇺 I'm writing POLITICO's Brussels Playbook today – tell me what's happening in your world ... [email protected]
May 21, 2025 at 9:53 AM
🇪🇺 I'm writing POLITICO's Brussels Playbook today – tell me what's happening in your world ... [email protected]
Reposted by Karl Mathiesen
NEW: Trump is perfectly
OK with ceding the clean energy economy to China.
Some green tech advocates thought they could convince Trump to compete.
Trump 2.0 sees putting money into it as enriching China and legitimizing clean energy.
w/ @karlmathiesen.bsky.social
www.politico.com/news/2025/05...
OK with ceding the clean energy economy to China.
Some green tech advocates thought they could convince Trump to compete.
Trump 2.0 sees putting money into it as enriching China and legitimizing clean energy.
w/ @karlmathiesen.bsky.social
www.politico.com/news/2025/05...
Some Republicans want to beat China on clean energy. Trump doesn’t care.
Efforts to preserve Biden-era tax breaks for green technology are running into an administration focused on fossil fuels — and unwilling to play on what it sees as Beijing's turf.
www.politico.com
May 19, 2025 at 11:26 PM
NEW: Trump is perfectly
OK with ceding the clean energy economy to China.
Some green tech advocates thought they could convince Trump to compete.
Trump 2.0 sees putting money into it as enriching China and legitimizing clean energy.
w/ @karlmathiesen.bsky.social
www.politico.com/news/2025/05...
OK with ceding the clean energy economy to China.
Some green tech advocates thought they could convince Trump to compete.
Trump 2.0 sees putting money into it as enriching China and legitimizing clean energy.
w/ @karlmathiesen.bsky.social
www.politico.com/news/2025/05...
NEW: One camp wants the United States to compete with Beijing on clean energy.
The other says playing in that game would make the United States the loser.
With @zcolman.bsky.social
www.politico.com/news/2025/05...
The other says playing in that game would make the United States the loser.
With @zcolman.bsky.social
www.politico.com/news/2025/05...
Some Republicans want to beat China on clean energy. Trump doesn’t care.
Efforts to preserve Biden-era tax breaks for green technology are running into an administration focused on fossil fuels — and unwilling to play on what it sees as Beijing's turf.
www.politico.com
May 19, 2025 at 11:16 PM
NEW: One camp wants the United States to compete with Beijing on clean energy.
The other says playing in that game would make the United States the loser.
With @zcolman.bsky.social
www.politico.com/news/2025/05...
The other says playing in that game would make the United States the loser.
With @zcolman.bsky.social
www.politico.com/news/2025/05...
NEW: Lessons for Australia?
Unreported details of how UK paid off Turkey for COP26.
Inward investment conference in London
Votes for Turkish UN candidates
Backing for UN positions
+ 😬 according to 1 diplo a broken promise to back Turkey over Australia for COP31
www.politico.eu/article/aust...
Unreported details of how UK paid off Turkey for COP26.
Inward investment conference in London
Votes for Turkish UN candidates
Backing for UN positions
+ 😬 according to 1 diplo a broken promise to back Turkey over Australia for COP31
www.politico.eu/article/aust...
Can Australia pay off Turkey to host COP31? The Brits did.
A previously unreported package of investment pledges and U.N. support got Turkey to back down last time.
www.politico.eu
May 12, 2025 at 11:11 AM
NEW: Lessons for Australia?
Unreported details of how UK paid off Turkey for COP26.
Inward investment conference in London
Votes for Turkish UN candidates
Backing for UN positions
+ 😬 according to 1 diplo a broken promise to back Turkey over Australia for COP31
www.politico.eu/article/aust...
Unreported details of how UK paid off Turkey for COP26.
Inward investment conference in London
Votes for Turkish UN candidates
Backing for UN positions
+ 😬 according to 1 diplo a broken promise to back Turkey over Australia for COP31
www.politico.eu/article/aust...
NEW: Confidential EU report warns UK plans to strip nature protections in planning reforms could breach of the Brexit trade deal.
Also notes senior UK politicians "ridiculing" of green laws and Rachel Reeves banging on about newts and bats.
www.politico.eu/article/newt...
Also notes senior UK politicians "ridiculing" of green laws and Rachel Reeves banging on about newts and bats.
www.politico.eu/article/newt...
EU warns Britain’s war on newts could violate Brexit deal
Leaked EU report raises alarm about U.K. planning bill’s bonfire of environmental protections.
www.politico.eu
May 9, 2025 at 10:31 AM
NEW: Confidential EU report warns UK plans to strip nature protections in planning reforms could breach of the Brexit trade deal.
Also notes senior UK politicians "ridiculing" of green laws and Rachel Reeves banging on about newts and bats.
www.politico.eu/article/newt...
Also notes senior UK politicians "ridiculing" of green laws and Rachel Reeves banging on about newts and bats.
www.politico.eu/article/newt...
NEW: Trump officials arrived in the UK last week with a simple message: China is a malign actor, benefiting from misguided climate policies, and the world is better off copying America's newfound embrace of fossil fuels.
It was met with a shrug.
www.politico.eu/article/trum...
It was met with a shrug.
www.politico.eu/article/trum...
Trump’s efforts to split Europe and China on clean energy fall flat
The U.S. argument against the green transition felt “quiet and out of place,” said one official.
www.politico.eu
April 28, 2025 at 12:14 PM
NEW: Trump officials arrived in the UK last week with a simple message: China is a malign actor, benefiting from misguided climate policies, and the world is better off copying America's newfound embrace of fossil fuels.
It was met with a shrug.
www.politico.eu/article/trum...
It was met with a shrug.
www.politico.eu/article/trum...
NEW: The IEA's research has shown increasingly optimistic outlooks for clean power and gloomy forecasts for oil.
The Trump administration wants that to change.
w/ @saraschonhardt.bsky.social , @charliecooper8.bsky.social and @nicolascamut.bsky.social
www.politico.eu/article/dona...
The Trump administration wants that to change.
w/ @saraschonhardt.bsky.social , @charliecooper8.bsky.social and @nicolascamut.bsky.social
www.politico.eu/article/dona...
Trump officials pressure world’s top energy agency to drop climate mission
U.S. and European officials are sparring in meetings of the International Energy Agency, which helps guide global investments and policies.
www.politico.eu
April 25, 2025 at 8:31 AM
NEW: The IEA's research has shown increasingly optimistic outlooks for clean power and gloomy forecasts for oil.
The Trump administration wants that to change.
w/ @saraschonhardt.bsky.social , @charliecooper8.bsky.social and @nicolascamut.bsky.social
www.politico.eu/article/dona...
The Trump administration wants that to change.
w/ @saraschonhardt.bsky.social , @charliecooper8.bsky.social and @nicolascamut.bsky.social
www.politico.eu/article/dona...