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Felix Schaumann @felixschaumann.bsky.social · 12d

Is "overshoot" replacing "tipping points" in the climate discourse?

I wrote a short blog post exploring this idea.

Bottom line: it's all about urgency and irreversibility, but overshoot can circumvent some problems that the tipping points framing has.

Read the full post here: s.gwdg.de/wRWft8

Is Climate Overshoot the New Tipping Points? – Climate Matters

climatematters.blogs.uni-hamburg.de

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Reposted by Felix Schaumann

Rupert Stuart-Smith @rupertstuartsmith.bsky.social · Apr 22

🚨 We are hiring! I am looking for a climate scientist postdoc to join my team at Oxford working on a project on climate change and health until Feb 2028. For more details: www.linkedin.com/feed/update/...

📅 Apply by 14 May here: my.corehr.com/pls/uoxrecru...

🚨 We are hiring! I am looking for a postdoc to join my team at the… | Rupert Stuart-Smith

🚨 We are hiring! I am looking for a postdoc to join my team at the University of Oxford, working on a Wellcome Trust-funded project on climate change and health. The post will run until February 2028....

www.linkedin.com

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Reposted by Felix Schaumann

Max-Planck-Gesellschaft @maxplanck.de · Mar 13

[Video] AMOC-Schwächung könnte Billionen kosten. Die #AMOC-Abschwächung verringert die #CO₂-Aufnahme, verstärkt die Erderwärmung & erhöht die Kosten - so die neue Studie von @felixschaumann.bsky.social & @edualastrue.bsky.social (MPI für Meteorologie). Carolin Riethmüller fasst für Euch zusammen➡️🔗

Billionen Kosten durch schwächere Meeresströmung | Wissen Was News

YouTube video by MaxPlanckSociety

youtu.be

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Felix Schaumann @felixschaumann.bsky.social · Mar 10

Thanks a lot! We look at the global ocean, so we didn't check whether AABW might counteract this, but the net effect is to recuce carbon uptake. The main difference to LGM studies is that we have emissions scenarios, so the downwelling water is relatively more carbon-rich than the upwelling water.

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Reposted by Felix Schaumann

Proceedings of the National Academy of Sciences @pnas.org · Mar 3

Climate change could weaken the Atlantic Meridional Overturning Circulation (AMOC), which would cool the Northern Hemisphere. A weaker AMOC could also diminish ocean carbon uptake, thus increasing the social cost of carbon. In PNAS: www.pnas.org/doi/10.1073/...

Overview of the modeling approach. (A) The Max Planck Institute Earth System Model is used to simulate climate states with an artificially weakened Atlantic Meridional Overturning Circulation (AMOC). (B) The resulting changes in annual ocean carbon storage are then analyzed as a function of the simulated AMOC. (C) The strength of the AMOC carbon feedback is estimated until 2100. (D) The economic impact of these projected changes is then analyzed.

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Reposted by Felix Schaumann

Annie Leymarie @annieleymarie.bsky.social · Mar 2

Economic impact studies tend to find a weaker AMOC globally beneficial, as lower temperatures in the Northern Hemisphere would offset some global warming & associated economic damages - but new paper shows this ignores reduced C uptake by oceans & Social Cost of Carbon. See bsky.app/profile/feli...

CEN University of Hamburg @cenunihh.bsky.social · Feb 25

💰 Weaker ocean circulation may cost trillions

A new study by @felixschaumann.bsky.social and @edualastrue.bsky.social in @pnas.org reveals that a weakening Atlantic Meridional Overturning Circulation (AMOC) could lead to costs of several trillion euros. #CLICCS #climate #ocean @uni-hamburg.de

Weaker ocean current could cost trillions

Faculties

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Reposted by Felix Schaumann

DIE ZEIT @zeit.de · Feb 26

Der Kollaps einer Meeresströmung könnte Europa extrem kalte Winter wie in Kanada bringen, warnten Forschende zuletzt. Unwahrscheinlich, sagt eine neue Studie. Was stimmt?

AMOC: Eine kleine Wahrscheinlichkeit, dass etwas sehr Schlimmes passiert

Der Kollaps einer Meeresströmung könnte Europa extrem kalte Winter wie in Kanada bringen, warnten Forschende zuletzt. Unwahrscheinlich, sagt eine neue Studie. Was stimmt?

www.zeit.de

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Reposted by Felix Schaumann

Moritz Drupp @moritzdrupp.bsky.social · Feb 25

Check out this great paper by @felixschaumann.bsky.social with @edualastrue.bsky.social out now in @pnas.org that integrates climate science with climate economics to study the social cost of carbon implications of reduced AMOC weakening. Super impressive work for a first PhD chapter👇

Felix Schaumann @felixschaumann.bsky.social · Feb 25

🚨 First PhD paper in @pnas.org 🥳

🌊 @edualastrue.bsky.social and I looked at how much less CO2 will be taken up by the ocean if the #AMOC weakens - and how this reduced ocean carbon uptake affects the social cost of CO2 emissions.

📝 Read the paper here: doi.org/10.1073/pnas...

🧵 A thread [1/11]

PNAS

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

doi.org

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Felix Schaumann @felixschaumann.bsky.social · Feb 26

thanks!

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Reposted by Felix Schaumann

CEN University of Hamburg @cenunihh.bsky.social · Feb 25

💰 Weaker ocean circulation may cost trillions

A new study by @felixschaumann.bsky.social and @edualastrue.bsky.social in @pnas.org reveals that a weakening Atlantic Meridional Overturning Circulation (AMOC) could lead to costs of several trillion euros. #CLICCS #climate #ocean @uni-hamburg.de

Weaker ocean current could cost trillions

Faculties

buff.ly

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Reposted by Felix Schaumann

Andy Revkin 🌎 ✍🏼 🪕 ☮️ revkin.substack.com @revkin.bsky.social · Feb 25

No cheers for warming slowdown from potential weakening of AMOC given carbon drawdown impact. New study.

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Reposted by Felix Schaumann

Meertext @meertext.bsky.social · Feb 25

Die Abschwächung der #AMOC bietet neben den bereits oft prognostizierten Abkühlungseffekten für Nordeuropa weitere spannende Skills: Sie wird wohl auch die CO2-Aufnahmekapazität des Nordatlantiks verringern.
#Klimakrise #Nordatlantik #Ozean #Ozeanographie

Felix Schaumann @felixschaumann.bsky.social · Feb 25

🚨 First PhD paper in @pnas.org 🥳

🌊 @edualastrue.bsky.social and I looked at how much less CO2 will be taken up by the ocean if the #AMOC weakens - and how this reduced ocean carbon uptake affects the social cost of CO2 emissions.

📝 Read the paper here: doi.org/10.1073/pnas...

🧵 A thread [1/11]

PNAS

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

doi.org

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[11/11]

Of interest? @ayeshatandon.carbonbrief.org @daisydunne.carbonbrief.org @klimareporter.bsky.social @fionaharvey.bsky.social @jonathan-watts.bsky.social @dpcarrington.bsky.social @muellerjung.bsky.social @sventitz.bsky.social @jonaswaack.bsky.social @fischblog.bsky.social @revkin.bsky.social

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[10/11]

📖 If you are still curious, check out the news items by the CEN research center @cenunihh.bsky.social of the University of Hamburg @uni-hamburg.de and the Max Planck Institute for Meteorology (mas.to/@MPI_Meteo@w...).

mas.to

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[9/11] Where to go from here?

With one more impact channel of AMOC weakening - probably not the most relevant - the picture already changes quite a bit.

A lot of other impacts remain, and we should research them if we want to properly understand the risks that are associated with a changing AMOC.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[8/11]

The SCC is raised by about 1% because of the AMOC carbon feedback (right panel).

This is of similar magnitude, but of opposite sign, to the previous economic impact estimates of AMOC weakening (left panel):

Relative SCC changes due to AMOC temperature effects and AMOC carbon effects in comparison.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[7/11] What do we find? Economic impacts

Looking at the additional (Burke) economic damages induced by this feedback, we estimate numbers in the range of trillion US dollars, cumulated over this century.

But the more important economic indicator is the social cost of carbon (SCC).

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[6/11]

But the cumulative effect for this century is - depending on the projection of AMOC strength - between 4 and 12 PgC.

For context: Every year we emit around 10 PgC, so by 2100, AMOC weakening could reduce ocean storage by up to a full year of current emissions to the atmosphere.

CMPI6 projections of AMOC strength and the associated ocean carbon storage reductions in 2100.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[5/11] What do we find? Carbon cycle impacts

We find that, in a year with a 1 Sv weaker AMOC, 0.023 PgC less will flow into the ocean. That doesn't sound like much, maybe 0.2% of current anthropogenic CO2 emissions.

Scatter plot of carbon flux changes over AMOC strength with a linear regression line.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[4/11] How do we do it?

Our methods in a cartoon:

a) freshwater hosing in a biogeochemically-only coupled ESM
b) yearly carbon flux changes as a function of yearly AMOC strength
c) cumulative carbon flux reductions in the 21st century following CMIP6 AMOC projections
d) changes in SCC estimates

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[3/11]

But what about all the other climate impacts that AMOC weakening would have, beyond just surface temperatures?

They have yet to be integrated into economic impact assessments, and we start by looking at the carbon cycle.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

[2/11] Why is this relevant?

Existing economic impact estimates deem AMOC weakening globally beneficial. Why?

Because a weaker AMOC would reduce temperatures in the Northern Hemisphere and thereby locally offset parts of global warming and the associated economic damages.

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Felix Schaumann @felixschaumann.bsky.social · Feb 25

🚨 First PhD paper in @pnas.org 🥳

🌊 @edualastrue.bsky.social and I looked at how much less CO2 will be taken up by the ocean if the #AMOC weakens - and how this reduced ocean carbon uptake affects the social cost of CO2 emissions.

📝 Read the paper here: doi.org/10.1073/pnas...

🧵 A thread [1/11]

PNAS

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

doi.org

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Reposted by Felix Schaumann

ClimateFran @climatefran.bsky.social · Dec 17

Excited to announce a new @pnas.org publication on the Social Cost of Carbon. We integrate evidence from the literature and expert survey to provide an SCC distribution inclusive of both parametric and structural uncertainties. Our mean 2020 value is $283 per ton CO2
www.pnas.org/doi/10.1073/...

Synthesis of evidence yields high social cost of carbon due to structural model variation and uncertainties | PNAS

Estimating the cost to society from a ton of CO2—termed the social cost of carbon (SCC)—requires connecting a model of the climate system with a re...

www.pnas.org

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Reposted by Felix Schaumann

Bob Kopp @bobkopp.net · Dec 3

In a new interdisciplinary Nature Climate Change Perspective paper, led by me, @lisgilmore and Rachael Shwom, we offer a critical perspective on #climate and social “tipping points.” 🎁: rdcu.be/d2gBC 🧵

‘Tipping points’ confuse and can distract from urgent climate action

Nature Climate Change - The tipping points framing is widely used in climate discussions but receives mixed feedback. This Perspective critiques it for oversimplifying the complexities of natural...

rdcu.be

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