Prof. Stefan Rahmstorf
@rahmstorf.bsky.social
Climate scientist, professor of Physics of the Oceans in Potsdam. Opinions my own.
Stefan Rahmstorf is a German oceanographer and climatologist. Since 2000, he has been a Professor of Physics of the Oceans at Potsdam University. He studied physical oceanography at Bangor University and received his Ph.D. in oceanography from Victoria University of Wellington (1990). His work focuses on the role of ocean currents in climate change. He was one of the lead authors of the IPCC Fourth Assessment Report. .. more
Environmental science
46%
Geology
21%
Reposted by Michael Wagner
Geheimdienste warnen vor Atlantik-Kipppunkt – Europas Wärmepumpe droht der Kollaps
Die AMOC-Strömung steht vor dem Kollaps. Selbst Geheimdienste schlagen Alarm, denn die Konsequenzen des Wetterphänomens sind extrem.
www.merkur.de
Regierungen nehmen dieses Risiko zunehmend ernst angesichts neuer Befunde der Forschung.
Kleine Ergänzung: "Unsere Simulationen" im Zitat bezieht sich auf die Simulationen vieler Institute für den IPCC-Bericht, die in unserer Studie (➡️ Kommentar) ausgewertet wurden. 🌊
www.merkur.de/wissen/pflan...
Kleine Ergänzung: "Unsere Simulationen" im Zitat bezieht sich auf die Simulationen vieler Institute für den IPCC-Bericht, die in unserer Studie (➡️ Kommentar) ausgewertet wurden. 🌊
www.merkur.de/wissen/pflan...
Die Strömung folgt dem amerikanischen Kontinentalrand in ihrer Tiefe (2-3 km). Das hat - stark vereinfacht - mit der Corioliskraft zu tun, die das Wasser nach rechts drücken will.
Thanks, I wasn’t aware that might not be familiar to all. Density is the weight of a given volume. How much does a liter of sea water weigh? The saltier and colder the water is, the heavier it is. Heavier water pushes lighter water away, which drives ocean currents (to put it very simply).
Zack Labe
@zacklabe.com
· 3d
2025 was the hottest year on record for ocean heat content. Unfortunately, we now say this every year. 🥹
"In addition to setting a new record in 2025, the global
ocean continues to show sustained and intensified warming."
+ #OpenAccess Study: doi.org/10.1007/s003...
+ Data: www.ocean.iap.ac.cn
"In addition to setting a new record in 2025, the global
ocean continues to show sustained and intensified warming."
+ #OpenAccess Study: doi.org/10.1007/s003...
+ Data: www.ocean.iap.ac.cn
I started to study oceanography in 1982 and have worked on AMOC instability since 1990, and have never come across a scientific paper suggesting anything like that.
Read the caption? All 3 panels show the temperature trend over the 21st Century.
I’m sure you read that in the media, but not any scientific paper 🙃
Nordic Overturning Increases as AMOC Weakens in Response to Global Warming
Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is weakening in response to global warming, while Nordic Seas Overturning Circulation (NOC) is projected to increase. So far, no causal...
egusphere.copernicus.org
The increase in overturning to the Nordic Seas is a temporary phenomenon in global warming scenarios. At the point when convection stops in box 2/5, soon after convection in the Nordic Seas follows and Nordic overturning shuts down. Read the preprint here: egusphere.copernicus.org/preprints/20...
The next year I got a Master student to look at this: Sasha Roewer. We added deep convection as a mechanism that can tip on or off. Sasha's final model thus looks a bit more complex! It also showed: lower density in box 2/5 weakes AMOC and increases Nordic Sea overturning. But it showed more...
In 2023 I designed a simple box model to illustrate the mechanism: if the density in box 2 (Irminger Sea) decreases, the AMOC weakens but the Nordic Seas exchange strengthens, because the density difference between box 5 and 2 (which drives that flow) increases - as in the CM2.6 climate model.
A strong warming in the Norwegian Sea. So we wondered: could this also be linked to the #AMOC? So we got Bachelor student Lukas Fiedler onto it. He showed in his thesis in 2020 that in the CM2.6 climate model we had used in Caesar et al. 2018, Nordic Sea overturning increases as AMOC weakens.
That didn't make sense to me: why would these two currents behave the same?
In 2018 we published a paper showing a 'fingerprint' sea surface temperature pattern due to an AMOC slowdown: a 'cold blob' and a strong warming off the American coast. But it showed more... www.nature.com/articles/s41...
In 2018 we published a paper showing a 'fingerprint' sea surface temperature pattern due to an AMOC slowdown: a 'cold blob' and a strong warming off the American coast. But it showed more... www.nature.com/articles/s41...
A short thread about the back story behind our new study. 🌊
A pile of evidence suggests the Atlantic overturning #AMOC (and its surface branch North Atlantic Current) has slowed. But some colleagues were sceptical, arguing the Norwegian Current and its deep return flow haven't slowed. 1/6
A pile of evidence suggests the Atlantic overturning #AMOC (and its surface branch North Atlantic Current) has slowed. But some colleagues were sceptical, arguing the Norwegian Current and its deep return flow haven't slowed. 1/6
Meinung: Woher die gewaltige Energie des Klimawandels stammt
In jedem Liter eingeatmeter Luft stecken 3.432.000.000.000.000.000 CO2-Moleküle fossiler Brennstoffe. Gesundheitsschädlich ist das zwar nicht - aber man muss es wissen, um den Klimawandel zu verstehen...
www.spiegel.de
Um die Erde zu erwärmen braucht es gewaltige Energiemengen.
Weil die Energieströme ständig gemessen werden wissen wir auch, woher die Energie stammt, die unser Klima aufheizt.
www.spiegel.de/wissenschaft...
Weil die Energieströme ständig gemessen werden wissen wir auch, woher die Energie stammt, die unser Klima aufheizt.
www.spiegel.de/wissenschaft...
Geglättete Kurve ohne zwischenjährliche Schwankungen. Die 1,3 Grad sind der relevante Wert zum Vergleich mit dem 1,5-Grad Klimaziel des Pariser Abkommens, das sich ebenfalls nicht auf einzelne Jahre bezieht.
Climate change context: the last 2000 years
Updated climate indicator visualisations
open.substack.com
Quelle der Grafik: open.substack.com/pub/climatel...
Wobei die Daten von Temperatur und CO2 auch schon im IPCC-Bericht gezeigt sind.
Wobei die Daten von Temperatur und CO2 auch schon im IPCC-Bericht gezeigt sind.
After the US admin cancelled the $B Climate + Weather Disaster dataset, @climatecentral.org hired the scientists who ran it and set it back up.
Now the 2025 numbers are in: it's 3rd highest year on record and highest year w/o land-falling hurricanes.
More: www.climatecentral.org/climate-serv...
Now the 2025 numbers are in: it's 3rd highest year on record and highest year w/o land-falling hurricanes.
More: www.climatecentral.org/climate-serv...
Meeresspiegel steigt noch Jahrhunderte weiter wenn die globale Temperatur stabilisiert ist, das Ausmaß ist als “sea level commitment” bekannt. Das sind mehrere Meter selbst bei 2 Grad Erwärmung.
Letzte Eiszeit: 8 Grad kälter, 120 Meter niedrigerer Meeresspiegel.
Letzte Eiszeit: 8 Grad kälter, 120 Meter niedrigerer Meeresspiegel.
Hier zur Einordnung dieser Nachricht die globalen Daten der letzten 2024 Jahre.