Prof. Stefan Rahmstorf
@rahmstorf.bsky.social
Climate scientist, professor of Physics of the Oceans in Potsdam. Opinions my own.
Giving in to authoritarianism rather than sticking up for free speech. What has become of the BBC?
I wish I didn’t have to share this. But the BBC has decided to censor my first Reith Lecture.
They deleted the line in which I describe Donald Trump as “the most openly corrupt president in American history.” /1
They deleted the line in which I describe Donald Trump as “the most openly corrupt president in American history.” /1
November 25, 2025 at 1:02 PM
Giving in to authoritarianism rather than sticking up for free speech. What has become of the BBC?
It should be obvious by now that we cannot make the future of human civilisation dependent on whether the fossil fuel vendors vote for ending fossil fuel use.
Rather, it is up to those who buy fossil fuels to end their lethal addiction fast, before it is too late.
Rather, it is up to those who buy fossil fuels to end their lethal addiction fast, before it is too late.
My latest: #COP30, global climate politics, and what happens next — for @theguardian.com
www.theguardian.com/commentisfre...
www.theguardian.com/commentisfre...
November 25, 2025 at 12:58 PM
It should be obvious by now that we cannot make the future of human civilisation dependent on whether the fossil fuel vendors vote for ending fossil fuel use.
Rather, it is up to those who buy fossil fuels to end their lethal addiction fast, before it is too late.
Rather, it is up to those who buy fossil fuels to end their lethal addiction fast, before it is too late.
Reposted by Prof. Stefan Rahmstorf
📢 New paper on the impacts of AMOC collapse on European hydroclimate. 🌊
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
Changing European hydroclimate under a collapsed AMOC in the Community Earth System Model
Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is expected to weaken or even collapse under anthropogenic climate change. Given the importance of the AMOC in the present-day climate,...
doi.org
November 21, 2025 at 2:41 PM
📢 New paper on the impacts of AMOC collapse on European hydroclimate. 🌊
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
When a government speaks responsibly about climate risks. Iceland's climate minister Jóhannsson:
"We believe that confronting climate tipping points and the risks they pose openly is not a sign of 'pessimism' or 'alarmism' but a sign of realism and responsibility."
youtu.be/B-0eQnEEsYA?...
"We believe that confronting climate tipping points and the risks they pose openly is not a sign of 'pessimism' or 'alarmism' but a sign of realism and responsibility."
youtu.be/B-0eQnEEsYA?...
After COP30 Fire and Floods: AMOC Shutdown
YouTube video by International Cryosphere Climate Initiative
youtu.be
November 23, 2025 at 6:43 PM
When a government speaks responsibly about climate risks. Iceland's climate minister Jóhannsson:
"We believe that confronting climate tipping points and the risks they pose openly is not a sign of 'pessimism' or 'alarmism' but a sign of realism and responsibility."
youtu.be/B-0eQnEEsYA?...
"We believe that confronting climate tipping points and the risks they pose openly is not a sign of 'pessimism' or 'alarmism' but a sign of realism and responsibility."
youtu.be/B-0eQnEEsYA?...
The sea surface is not horizontal; its slope is influenced by ocean currents and the density distribution.
November 22, 2025 at 11:21 AM
The sea surface is not horizontal; its slope is influenced by ocean currents and the density distribution.
November 22, 2025 at 11:20 AM
The sea surface is not horizontal; its slope is influenced by ocean currents and the density distribution.
“… because ignoring systemic risk is unacceptable!”
Iceland’s climate minister in Belém on the risk of major #AMOC changes.
“Prevention remains our first duty.”
Listen to him (and my talk 🌊) here:
youtu.be/B-0eQnEEsYA?...
The first 2 mins show how the live stream was ended by a 🔥.
Iceland’s climate minister in Belém on the risk of major #AMOC changes.
“Prevention remains our first duty.”
Listen to him (and my talk 🌊) here:
youtu.be/B-0eQnEEsYA?...
The first 2 mins show how the live stream was ended by a 🔥.
After COP30 Fire and Floods: AMOC Shutdown
YouTube video by International Cryosphere Climate Initiative
youtu.be
November 22, 2025 at 11:10 AM
“… because ignoring systemic risk is unacceptable!”
Iceland’s climate minister in Belém on the risk of major #AMOC changes.
“Prevention remains our first duty.”
Listen to him (and my talk 🌊) here:
youtu.be/B-0eQnEEsYA?...
The first 2 mins show how the live stream was ended by a 🔥.
Iceland’s climate minister in Belém on the risk of major #AMOC changes.
“Prevention remains our first duty.”
Listen to him (and my talk 🌊) here:
youtu.be/B-0eQnEEsYA?...
The first 2 mins show how the live stream was ended by a 🔥.
And of course there’s the extra sea-level rise, by half a meter or more. bsky.app/profile/rahm...
It further shows a similar sea-level rise pattern after #AMOC shutdown as we found in Levermann et al. 2005, with the dynamic rise extending down into the South Atlantic. (That would be added to any global rise caused by climate warming.) 🧵
➡️ agupubs.onlinelibrary.wiley.com/doi/full/10....
➡️ agupubs.onlinelibrary.wiley.com/doi/full/10....
November 22, 2025 at 5:55 AM
And of course there’s the extra sea-level rise, by half a meter or more. bsky.app/profile/rahm...
Many people think about cold in Northern Europe if the Atlantic Ocean current system #AMOC fails. But that wouldn’t be the only problem for Europe by far.
This new study shows that severe drought is another one. 🌊
This new study shows that severe drought is another one. 🌊
📢 New paper on the impacts of AMOC collapse on European hydroclimate. 🌊
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
Changing European hydroclimate under a collapsed AMOC in the Community Earth System Model
Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is expected to weaken or even collapse under anthropogenic climate change. Given the importance of the AMOC in the present-day climate,...
doi.org
November 22, 2025 at 5:52 AM
Many people think about cold in Northern Europe if the Atlantic Ocean current system #AMOC fails. But that wouldn’t be the only problem for Europe by far.
This new study shows that severe drought is another one. 🌊
This new study shows that severe drought is another one. 🌊
Hey Murdoch fake-news media! The study you report on here
1. Predicts nothing but is about the past.
2. Is not about Gulf Stream but #AMOC.
3. An AMOC collapse wouldn’t cause an Ice Age.
Incompetence or intent to confuse?
The study by Ren et al shows AMOC has weakened: www.nature.com/articles/s43...
1. Predicts nothing but is about the past.
2. Is not about Gulf Stream but #AMOC.
3. An AMOC collapse wouldn’t cause an Ice Age.
Incompetence or intent to confuse?
The study by Ren et al shows AMOC has weakened: www.nature.com/articles/s43...
November 18, 2025 at 1:06 PM
Hey Murdoch fake-news media! The study you report on here
1. Predicts nothing but is about the past.
2. Is not about Gulf Stream but #AMOC.
3. An AMOC collapse wouldn’t cause an Ice Age.
Incompetence or intent to confuse?
The study by Ren et al shows AMOC has weakened: www.nature.com/articles/s43...
1. Predicts nothing but is about the past.
2. Is not about Gulf Stream but #AMOC.
3. An AMOC collapse wouldn’t cause an Ice Age.
Incompetence or intent to confuse?
The study by Ren et al shows AMOC has weakened: www.nature.com/articles/s43...
While the Reuters report says an AMOC shutdown "could trigger a modern-day ice age", this is not what we scientists call an ice age. Rather, it is a regional cooling, plus other severe impacts on sea level, rainfall patterns, weather extremes, marine ecosystems and ocean carbon uptake.
November 18, 2025 at 10:57 AM
While the Reuters report says an AMOC shutdown "could trigger a modern-day ice age", this is not what we scientists call an ice age. Rather, it is a regional cooling, plus other severe impacts on sea level, rainfall patterns, weather extremes, marine ecosystems and ocean carbon uptake.
Iceland Climate Minister Johannsson: "It is a direct threat to our national resilience and security. (This) is the first time a specific climate-related phenomenon has been formally brought before the National Security Council as a potential existential threat."
www.reuters.com/sustainabili...
www.reuters.com/sustainabili...
Iceland deems possible Atlantic current collapse a security risk
Iceland has designated the potential collapse of a major Atlantic Ocean current system a national security concern and an existential threat, enabling its government to strategize for worst-case scenarios, the country's climate minister told Reuters.
www.reuters.com
November 18, 2025 at 10:52 AM
Iceland Climate Minister Johannsson: "It is a direct threat to our national resilience and security. (This) is the first time a specific climate-related phenomenon has been formally brought before the National Security Council as a potential existential threat."
www.reuters.com/sustainabili...
www.reuters.com/sustainabili...
A funny postscript: when I was a young postdoc in the 1990s I was told by a professor that using colour graphics wasn't serious science.
And that only bad scientists speak to journalists.
And that only bad scientists speak to journalists.
November 17, 2025 at 7:17 PM
A funny postscript: when I was a young postdoc in the 1990s I was told by a professor that using colour graphics wasn't serious science.
And that only bad scientists speak to journalists.
And that only bad scientists speak to journalists.
A little reminder of science history: air temperature change after a shutdown of the Atlantic overturning circulation #AMOC, as simulated in climate models 36 years apart.
Suki Manabe went on to win the physics Nobel prize in 2021 jointly with his colleagues Klaus Hasselmann and Giorgio Parisi.
Suki Manabe went on to win the physics Nobel prize in 2021 jointly with his colleagues Klaus Hasselmann and Giorgio Parisi.
November 17, 2025 at 7:11 PM
A little reminder of science history: air temperature change after a shutdown of the Atlantic overturning circulation #AMOC, as simulated in climate models 36 years apart.
Suki Manabe went on to win the physics Nobel prize in 2021 jointly with his colleagues Klaus Hasselmann and Giorgio Parisi.
Suki Manabe went on to win the physics Nobel prize in 2021 jointly with his colleagues Klaus Hasselmann and Giorgio Parisi.
Reposted by Prof. Stefan Rahmstorf
I wouldn't board an aircraft, a bus, a train, a ship or even get in a car that had a 5% chance of crashing. Now AMOC collapse is closing in on over 25% probability we are all being boarded to a mad future.
Excellent eye opener of a presentation. Educate yourself, watch it.
youtu.be/ULJXqOZuY-8
Excellent eye opener of a presentation. Educate yourself, watch it.
youtu.be/ULJXqOZuY-8
Is the Atlantic Ocean circulation close to tipping?
YouTube video by Earth System Analysis - Potsdam Institute
youtu.be
November 16, 2025 at 4:41 PM
I wouldn't board an aircraft, a bus, a train, a ship or even get in a car that had a 5% chance of crashing. Now AMOC collapse is closing in on over 25% probability we are all being boarded to a mad future.
Excellent eye opener of a presentation. Educate yourself, watch it.
youtu.be/ULJXqOZuY-8
Excellent eye opener of a presentation. Educate yourself, watch it.
youtu.be/ULJXqOZuY-8
Reposted by Prof. Stefan Rahmstorf
I found the link for your article mentioned at the end of your presentation, which details further possible consequences of AMOC shutdown. Thank you for your hard work.
tos.org/oceanography...
tos.org/oceanography...
tos.org
November 16, 2025 at 4:09 PM
I found the link for your article mentioned at the end of your presentation, which details further possible consequences of AMOC shutdown. Thank you for your hard work.
tos.org/oceanography...
tos.org/oceanography...
The government of Iceland now considers this a national security threat. www.arctictoday.com/iceland-sees...
And the Foreign Intelligence Service of Germany together with other German institutions published a National Climate Risk Assessment this year.
Here is what it says about #AMOC tipping risk.
And the Foreign Intelligence Service of Germany together with other German institutions published a National Climate Risk Assessment this year.
Here is what it says about #AMOC tipping risk.
November 16, 2025 at 3:58 PM
The government of Iceland now considers this a national security threat. www.arctictoday.com/iceland-sees...
And the Foreign Intelligence Service of Germany together with other German institutions published a National Climate Risk Assessment this year.
Here is what it says about #AMOC tipping risk.
And the Foreign Intelligence Service of Germany together with other German institutions published a National Climate Risk Assessment this year.
Here is what it says about #AMOC tipping risk.
Is the Atlantic Ocean circulation close to tipping?
Hear the latest science as I presented it last month at the ATLAS25 event in Helsinki.
Let me know if anything is unclear, or if you see good reasons why your government shouldn't immediately act on this. 🌊
youtu.be/ULJXqOZuY-8
Hear the latest science as I presented it last month at the ATLAS25 event in Helsinki.
Let me know if anything is unclear, or if you see good reasons why your government shouldn't immediately act on this. 🌊
youtu.be/ULJXqOZuY-8
Is the Atlantic Ocean circulation close to tipping?
YouTube video by Earth System Analysis - Potsdam Institute
youtu.be
November 16, 2025 at 3:35 PM
Is the Atlantic Ocean circulation close to tipping?
Hear the latest science as I presented it last month at the ATLAS25 event in Helsinki.
Let me know if anything is unclear, or if you see good reasons why your government shouldn't immediately act on this. 🌊
youtu.be/ULJXqOZuY-8
Hear the latest science as I presented it last month at the ATLAS25 event in Helsinki.
Let me know if anything is unclear, or if you see good reasons why your government shouldn't immediately act on this. 🌊
youtu.be/ULJXqOZuY-8
Reposted by Prof. Stefan Rahmstorf
Starke Rede, danke auch für die Quellen!
Hier ein direkt klickbarer Link:
www.pik-potsdam.de/~stefan/FFFD...
Hier ein direkt klickbarer Link:
www.pik-potsdam.de/~stefan/FFFD...
www.pik-potsdam.de
November 15, 2025 at 8:49 PM
Starke Rede, danke auch für die Quellen!
Hier ein direkt klickbarer Link:
www.pik-potsdam.de/~stefan/FFFD...
Hier ein direkt klickbarer Link:
www.pik-potsdam.de/~stefan/FFFD...
Reposted by Prof. Stefan Rahmstorf
#Klimakatastrophe #UK now:
#flood #storm #uk #claudiastorm #wales #birmingham #nottingham
A powerful surge of heavy rain from Storm Claudia has swept across the United Kingdom, triggering widespread flooding from Wales to the Midlands.
youtu.be/XfObiOczPA8?...
#flood #storm #uk #claudiastorm #wales #birmingham #nottingham
A powerful surge of heavy rain from Storm Claudia has swept across the United Kingdom, triggering widespread flooding from Wales to the Midlands.
youtu.be/XfObiOczPA8?...
Chaos in the UK Today: Storm Claudia Causes Severe Flooding in Wales, Birmingham and Nottingham!
YouTube video by NDH Weather
youtu.be
November 15, 2025 at 7:08 PM
#Klimakatastrophe #UK now:
#flood #storm #uk #claudiastorm #wales #birmingham #nottingham
A powerful surge of heavy rain from Storm Claudia has swept across the United Kingdom, triggering widespread flooding from Wales to the Midlands.
youtu.be/XfObiOczPA8?...
#flood #storm #uk #claudiastorm #wales #birmingham #nottingham
A powerful surge of heavy rain from Storm Claudia has swept across the United Kingdom, triggering widespread flooding from Wales to the Midlands.
youtu.be/XfObiOczPA8?...
In 2024, renewable energy accounted for over 90% of global power capacity expansion. That is because it makes economic sense. IRENA_DAT_RE_Capacity_Highlights_2025-1.pdf
November 16, 2025 at 11:22 AM
In 2024, renewable energy accounted for over 90% of global power capacity expansion. That is because it makes economic sense. IRENA_DAT_RE_Capacity_Highlights_2025-1.pdf
All nations committed under the Paris Agreement to limit global warming to 1.5 degC for good reason. Instead many governments are beholden to the fossil fuel lobby and even subsidize fossil fuel use with your money. We’re now at 1.4 degC & emissions are rising not falling.
unfccc.int/process-and-...
unfccc.int/process-and-...
November 15, 2025 at 4:09 PM
All nations committed under the Paris Agreement to limit global warming to 1.5 degC for good reason. Instead many governments are beholden to the fossil fuel lobby and even subsidize fossil fuel use with your money. We’re now at 1.4 degC & emissions are rising not falling.
unfccc.int/process-and-...
unfccc.int/process-and-...
“If we wait to cross tipping points before we act, it will be too late. The only credible risk management strategy is to act in advance.”
global-tipping-points.org/the-dartingt...
global-tipping-points.org/the-dartingt...
The Dartington Declaration - Global Tipping Points
The Dartington Declaration has emanated from scientific meetings held at Dartington Hall in England, and then a statement agreed at the Global Tipping Points Conference, on 30 June – 3 July 2025. It w...
global-tipping-points.org
November 15, 2025 at 3:21 PM
“If we wait to cross tipping points before we act, it will be too late. The only credible risk management strategy is to act in advance.”
global-tipping-points.org/the-dartingt...
global-tipping-points.org/the-dartingt...
Der Tagessspiegel über meine gestrige Rede in Berlin:
www.tagesspiegel.de/berlin/klima...
Die 45 Grad beziehen sich natürlich auf extreme Hitze: heute bis 39 Grad, künftig durchaus bis 45 Grad.
Mein Redetext (pdf) mit Links zu den Quellen: www.pik-potsdam.de/~stefan/FFFDemo_Rede_Berlin_Rahmstorf.pdf
www.tagesspiegel.de/berlin/klima...
Die 45 Grad beziehen sich natürlich auf extreme Hitze: heute bis 39 Grad, künftig durchaus bis 45 Grad.
Mein Redetext (pdf) mit Links zu den Quellen: www.pik-potsdam.de/~stefan/FFFDemo_Rede_Berlin_Rahmstorf.pdf
November 15, 2025 at 2:06 PM
Der Tagessspiegel über meine gestrige Rede in Berlin:
www.tagesspiegel.de/berlin/klima...
Die 45 Grad beziehen sich natürlich auf extreme Hitze: heute bis 39 Grad, künftig durchaus bis 45 Grad.
Mein Redetext (pdf) mit Links zu den Quellen: www.pik-potsdam.de/~stefan/FFFDemo_Rede_Berlin_Rahmstorf.pdf
www.tagesspiegel.de/berlin/klima...
Die 45 Grad beziehen sich natürlich auf extreme Hitze: heute bis 39 Grad, künftig durchaus bis 45 Grad.
Mein Redetext (pdf) mit Links zu den Quellen: www.pik-potsdam.de/~stefan/FFFDemo_Rede_Berlin_Rahmstorf.pdf
We have reached 1.4 degrees celsius #globalheating according to NASA data (smooth black trend line). Breaching 1.5 is now inevitable. From now on the fight is to keep overshoot as small and short as possible.
November 15, 2025 at 1:41 PM
We have reached 1.4 degrees celsius #globalheating according to NASA data (smooth black trend line). Breaching 1.5 is now inevitable. From now on the fight is to keep overshoot as small and short as possible.