Carl Schleussner
@carlschleussner.bsky.social
Climate Scientist at @iiasa.ac.at and Humboldt Universität zu Berlin Views are my own.
Here are the benchmarks, based on a novel post-AR6
database that's forthcoming under the Scenario Compass Initiative coordinated at @iiasa.ac.at
scenariocompass.org
database that's forthcoming under the Scenario Compass Initiative coordinated at @iiasa.ac.at
scenariocompass.org
November 15, 2025 at 1:21 PM
Here are the benchmarks, based on a novel post-AR6
database that's forthcoming under the Scenario Compass Initiative coordinated at @iiasa.ac.at
scenariocompass.org
database that's forthcoming under the Scenario Compass Initiative coordinated at @iiasa.ac.at
scenariocompass.org
There's an science statement that emerged from this weeks IAMC conference in Buzios, Brasil
5 key insights including 2035 benchmarks for GHG and fossil fuel reductions, PV+Solar upscaling
Check it out here: drive.google.com/file/d/1ofMw...
Open for sign-up here: forms.gle/FPrV3w6cMu8h...
5 key insights including 2035 benchmarks for GHG and fossil fuel reductions, PV+Solar upscaling
Check it out here: drive.google.com/file/d/1ofMw...
Open for sign-up here: forms.gle/FPrV3w6cMu8h...
November 15, 2025 at 1:21 PM
There's an science statement that emerged from this weeks IAMC conference in Buzios, Brasil
5 key insights including 2035 benchmarks for GHG and fossil fuel reductions, PV+Solar upscaling
Check it out here: drive.google.com/file/d/1ofMw...
Open for sign-up here: forms.gle/FPrV3w6cMu8h...
5 key insights including 2035 benchmarks for GHG and fossil fuel reductions, PV+Solar upscaling
Check it out here: drive.google.com/file/d/1ofMw...
Open for sign-up here: forms.gle/FPrV3w6cMu8h...
Ergebnis: Deutschlands Emissionen von 2020 bis 2045 werden die Wahrscheinlichkeit für extreme Hitzemonate (vorindustrielle 1-in-100 Jahresereignisse) in vulnerablen Regionen um 15-30% erhöhen. Die Aussage, dass “keine einzige Naturkatastrophe weniger geschehen würde”, ist nicht korrekt.
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July 11, 2025 at 5:11 AM
Ergebnis: Deutschlands Emissionen von 2020 bis 2045 werden die Wahrscheinlichkeit für extreme Hitzemonate (vorindustrielle 1-in-100 Jahresereignisse) in vulnerablen Regionen um 15-30% erhöhen. Die Aussage, dass “keine einzige Naturkatastrophe weniger geschehen würde”, ist nicht korrekt.
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Big climate litigation news today on Lliuya v. RWE in Germany. Court rules that major emitters may be held accountable under (German) civil law for climate damages internationally. This has far reaching implications. 1/
@germanwatch.bsky.social
www.justiz.nrw/presse/2025-...
@germanwatch.bsky.social
www.justiz.nrw/presse/2025-...
May 28, 2025 at 3:10 PM
Big climate litigation news today on Lliuya v. RWE in Germany. Court rules that major emitters may be held accountable under (German) civil law for climate damages internationally. This has far reaching implications. 1/
@germanwatch.bsky.social
www.justiz.nrw/presse/2025-...
@germanwatch.bsky.social
www.justiz.nrw/presse/2025-...
Huge congratulations @kornhuber.bsky.social for receiving the Outstanding Early Career Scientist Award #EGU25 from the Climate Division for your groundbreaking work on extreme weather and compound risks. Fantastic recognition of your high-impact work 👏👏👏 @iiasa.ac.at @egu.eu
April 29, 2025 at 9:00 AM
Huge congratulations @kornhuber.bsky.social for receiving the Outstanding Early Career Scientist Award #EGU25 from the Climate Division for your groundbreaking work on extreme weather and compound risks. Fantastic recognition of your high-impact work 👏👏👏 @iiasa.ac.at @egu.eu
🌍 SAVE THE DATE! Excited to announce that we'll be hosting the first-ever Climate Overshoot Conference at @iiasa.ac.at from Sep 30th - Oct 2nd, 2025. Thrilled to bring this critical conversation to Laxenburg/Vienna. 1/
iiasa.ac.at/events/sep-2...
iiasa.ac.at/events/sep-2...
March 19, 2025 at 9:08 AM
🌍 SAVE THE DATE! Excited to announce that we'll be hosting the first-ever Climate Overshoot Conference at @iiasa.ac.at from Sep 30th - Oct 2nd, 2025. Thrilled to bring this critical conversation to Laxenburg/Vienna. 1/
iiasa.ac.at/events/sep-2...
iiasa.ac.at/events/sep-2...
One day left to submit your abstract to #EGU25. And if you work on the topic of overshoot, please consider our session on:
Temperature overshoot and climate (ir)reversibility
meetingorganizer.copernicus.org/EGU25/sessio...
@eurogeosciences.bsky.social
Temperature overshoot and climate (ir)reversibility
meetingorganizer.copernicus.org/EGU25/sessio...
@eurogeosciences.bsky.social
January 14, 2025 at 11:11 AM
One day left to submit your abstract to #EGU25. And if you work on the topic of overshoot, please consider our session on:
Temperature overshoot and climate (ir)reversibility
meetingorganizer.copernicus.org/EGU25/sessio...
@eurogeosciences.bsky.social
Temperature overshoot and climate (ir)reversibility
meetingorganizer.copernicus.org/EGU25/sessio...
@eurogeosciences.bsky.social
Final PROVIDE General Assembly ongoing today. Check out more about this project here: www.provide-h2020.eu
And, if you don't have time, we have it summarised for you in 35 sec: www.youtube.com/watch?v=479c...
And, if you don't have time, we have it summarised for you in 35 sec: www.youtube.com/watch?v=479c...
December 12, 2024 at 11:34 AM
Final PROVIDE General Assembly ongoing today. Check out more about this project here: www.provide-h2020.eu
And, if you don't have time, we have it summarised for you in 35 sec: www.youtube.com/watch?v=479c...
And, if you don't have time, we have it summarised for you in 35 sec: www.youtube.com/watch?v=479c...
🚨Job Alert🚨: Come work with us at @iiasa.ac.at on Simple Climate Models and Emulators.
iiasa.ac.at/employment/j...
Some of our recent papers in that space:
gmd.copernicus.org/articles/17/...
www.nature.com/articles/s41...
iiasa.ac.at/employment/j...
Some of our recent papers in that space:
gmd.copernicus.org/articles/17/...
www.nature.com/articles/s41...
November 28, 2024 at 3:02 PM
🚨Job Alert🚨: Come work with us at @iiasa.ac.at on Simple Climate Models and Emulators.
iiasa.ac.at/employment/j...
Some of our recent papers in that space:
gmd.copernicus.org/articles/17/...
www.nature.com/articles/s41...
iiasa.ac.at/employment/j...
Some of our recent papers in that space:
gmd.copernicus.org/articles/17/...
www.nature.com/articles/s41...
And what's the level of confidence you need to say we've exceeded 1.5°C? "More likely than not", "likely", "very likely", virtually certain? It's a value judgement that's not for scientists to make IMO.
November 19, 2024 at 4:40 AM
And what's the level of confidence you need to say we've exceeded 1.5°C? "More likely than not", "likely", "very likely", virtually certain? It's a value judgement that's not for scientists to make IMO.
Here you go. Not 5%, but > 10% is within the C3 (66% below 2C) space. So in other words, a C3 pathways is not very likely to exceed 1.5°C (until of course it does so in obs).
www.nature.com/articles/s43...
www.nature.com/articles/s43...
November 18, 2024 at 7:45 PM
Here you go. Not 5%, but > 10% is within the C3 (66% below 2C) space. So in other words, a C3 pathways is not very likely to exceed 1.5°C (until of course it does so in obs).
www.nature.com/articles/s43...
www.nature.com/articles/s43...
Here's a rather recent version of it:
www.iea.org/reports/net-...
www.iea.org/reports/net-...
November 18, 2024 at 7:41 PM
Here's a rather recent version of it:
www.iea.org/reports/net-...
www.iea.org/reports/net-...
Not show I follow the argument here. Bc. it's clearly not a contradiction. And here's your 1/CP28 Para 28. Establishing trippling renewables, net zero energy systems, etc. On the back of a 1.5°C ambition. I see one thing enabling the other, not and either or.
November 18, 2024 at 1:01 PM
Not show I follow the argument here. Bc. it's clearly not a contradiction. And here's your 1/CP28 Para 28. Establishing trippling renewables, net zero energy systems, etc. On the back of a 1.5°C ambition. I see one thing enabling the other, not and either or.
Here's again from our paper, Glen. Exceedance probabilities for emission pathways show a continuum. Setting thresholds constitutes a value judgement. For both 1.5 exceedance and well below 2C. We made one argument for an interpretation, but others may disagree.
www.nature.com/articles/s43...
www.nature.com/articles/s43...
November 16, 2024 at 3:06 PM
Here's again from our paper, Glen. Exceedance probabilities for emission pathways show a continuum. Setting thresholds constitutes a value judgement. For both 1.5 exceedance and well below 2C. We made one argument for an interpretation, but others may disagree.
www.nature.com/articles/s43...
www.nature.com/articles/s43...
If you're interested (shameless promo): Check out our avoidable/unavoidable risk approach from the PROVIDE project:
climate-risk-dashboard.climateanalytics.org/impacts/expl...
climate-risk-dashboard.climateanalytics.org/impacts/expl...
November 15, 2024 at 12:45 PM
If you're interested (shameless promo): Check out our avoidable/unavoidable risk approach from the PROVIDE project:
climate-risk-dashboard.climateanalytics.org/impacts/expl...
climate-risk-dashboard.climateanalytics.org/impacts/expl...
Uncertainty cuts both ways. Warming could be a lot worse, of course. Need to be mindful of this. Here’s from @glenpeters.bsky.social article. These two statements can’t be true at the same time. In fact, as our probability increases to exceed 1.5°C, so it does for exceeding 2°C. 17/
November 15, 2024 at 9:54 AM
Uncertainty cuts both ways. Warming could be a lot worse, of course. Need to be mindful of this. Here’s from @glenpeters.bsky.social article. These two statements can’t be true at the same time. In fact, as our probability increases to exceed 1.5°C, so it does for exceeding 2°C. 17/
Forward looking, probability ranges increase even further. UNEP gap: This graph gives no one comfort. But in an optimistic interpretation there’s a remaining chance of not exceeding 1.5°C. Something to bank on? Certainly not. But also means it’s not certain that we’ll exceed 1.5°C. 16/
November 15, 2024 at 9:54 AM
Forward looking, probability ranges increase even further. UNEP gap: This graph gives no one comfort. But in an optimistic interpretation there’s a remaining chance of not exceeding 1.5°C. Something to bank on? Certainly not. But also means it’s not certain that we’ll exceed 1.5°C. 16/
Maybe we want to be a bit more certain. AR6 assessed likely range on global warming 1850–1900 to 2010–2019 is 0.8°C to 1.3°C (best estimate 1.07°C). If that range holds, it would mean only being able to state likely exceedance of 1.5°C in the 2040s. Maybe we even want to be virtually certain? 13/
November 15, 2024 at 9:54 AM
Maybe we want to be a bit more certain. AR6 assessed likely range on global warming 1850–1900 to 2010–2019 is 0.8°C to 1.3°C (best estimate 1.07°C). If that range holds, it would mean only being able to state likely exceedance of 1.5°C in the 2040s. Maybe we even want to be virtually certain? 13/
Increasing near-term ambition is urgently needed. And very much possible, even closing the 2030 and 2035 gap. See UNEP Gap Report. Will it happen? Political question and the outlook is grim. No doubt. 3/
November 15, 2024 at 9:54 AM
Increasing near-term ambition is urgently needed. And very much possible, even closing the 2030 and 2035 gap. See UNEP Gap Report. Will it happen? Political question and the outlook is grim. No doubt. 3/
In our model realisation, AMOC recovers with stabilising/declining temperatures and even shows 'overshoot' in the long-run. Disclaimer: No GIS meltwater feedback in the model. But still underscores the importance of scenario perspective. Full paper:
agupubs.onlinelibrary.wiley.com/doi/full/10....
agupubs.onlinelibrary.wiley.com/doi/full/10....
October 31, 2024 at 1:00 PM
In our model realisation, AMOC recovers with stabilising/declining temperatures and even shows 'overshoot' in the long-run. Disclaimer: No GIS meltwater feedback in the model. But still underscores the importance of scenario perspective. Full paper:
agupubs.onlinelibrary.wiley.com/doi/full/10....
agupubs.onlinelibrary.wiley.com/doi/full/10....
New paper alert🚨 - lot of discussions on #AMOC recently @rahmstorf.bsky.social . Here's another one from the #PROVIDE project focussing on AMOC dynamics under overshoot - strong non-linearities on multi-century timescales after overshoot. Great work by Fabrice Lacroix, Thomas Froelicher and others.
October 31, 2024 at 12:57 PM
New paper alert🚨 - lot of discussions on #AMOC recently @rahmstorf.bsky.social . Here's another one from the #PROVIDE project focussing on AMOC dynamics under overshoot - strong non-linearities on multi-century timescales after overshoot. Great work by Fabrice Lacroix, Thomas Froelicher and others.
Interesting. I was in Paris working as a science advisor to government. And don't recall it being discussed as aspirational. But as the key ask from vulnerable countries and the driver for climate ambition. E.g. the Eiffel tower pic from back then. 2013-2015 Periodic Review was critical for this.
October 29, 2024 at 5:55 AM
Interesting. I was in Paris working as a science advisor to government. And don't recall it being discussed as aspirational. But as the key ask from vulnerable countries and the driver for climate ambition. E.g. the Eiffel tower pic from back then. 2013-2015 Periodic Review was critical for this.
Thanks for clarifying what you meant. But e.g. this paragraph from your piece to me implies exactly that, a 'conspiracy'. Good to hear you didn't mean that. In which case you may want to revise this.
October 11, 2024 at 6:19 AM
Thanks for clarifying what you meant. But e.g. this paragraph from your piece to me implies exactly that, a 'conspiracy'. Good to hear you didn't mean that. In which case you may want to revise this.
To make matter even more challenging, rolling out carbon dioxide removal at scale is subject to a wide range of constraints. In fact, the scale of preventive removal capacity we estimate may only just be achievable within the sustainable limits of CDR deployment.
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October 9, 2024 at 4:54 PM
To make matter even more challenging, rolling out carbon dioxide removal at scale is subject to a wide range of constraints. In fact, the scale of preventive removal capacity we estimate may only just be achievable within the sustainable limits of CDR deployment.
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In a 1-in-4 outcome (75th quantile) around 400 Gt of net removals might be needed to return warming to 1.5°C in 2100 – nearly 10 Gt CO2 a year post net zero. This is comparable to the range of net negative emissions across the IPCC AR6 scenario ensemble.
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October 9, 2024 at 4:53 PM
In a 1-in-4 outcome (75th quantile) around 400 Gt of net removals might be needed to return warming to 1.5°C in 2100 – nearly 10 Gt CO2 a year post net zero. This is comparable to the range of net negative emissions across the IPCC AR6 scenario ensemble.
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