Annika Högner

The implications of overshooting 1.5 °C on Earth system tipping elements—a review The implications of overshooting 1.5 °C on Earth system tipping elements—a review, Ritchie, Paul D L, Steinert, Norman J, Abrams, Jesse F, Alkhayuon, Hassan, Arnscheidt, Constantin W, Bochow, Nils, Chapman, Ruth R, Clarke, Joseph, Dennis, Donovan P, Donges, Jonathan F, Flores, Bernardo M, Garbe, Julius, Högner, Annika, Huntingford, Chris, Lenton, Timothy M, Lohmann, Johannes, Lux-Gottschalk, Kerstin, Milkoreit, Manjana, Möller, Tessa, Pearce-Kelly, Paul, Pereira, Laura, Quinn, Courtney, Schleussner, Carl-Friedrich, Stuenzi, Simone M, Swingedouw, Didier, Van der Laan, Larissa N, Zickfeld, Kirsten, Wunderling, Nico

New review paper on "The implications of overshooting 1.5 °C on Earth system tipping elements"

Main points:
Overshooting 1.5°C raises risks of irreversible Earth-system tipping, which depends on peak warming and more so on how long critical thresholds are exceeded.

doi.org/10.1088/1748...

Exceeding 1.5 °C requires rethinking accountability in climate policy A scientific foundation is required to establish nations’ responsibilities in a hotter ‘overshoot’ world.

How should climate science and policy respond to a potential exceedance of 1.5°C? We provide our perspective on this in a new @Nature comment 🔗 nature.com/articles/d41586-026-00247-y led by Gaurav Ganti with Sabine Fuss, @joerirogelj.bsky.social, @setupelz.bsky.social & Keywan Riahi 1/

US withdrawal from Paris takes effect today. Our new analysis shows progress, and defines the gap to 1.5°C that we can still (and must) close. The report: www.climate-resource.com/reports/ndcs... ; The summary: www.climate-resource.com/reports/ndcs...

Newspaper article "Increase in Carbon Dioxide May Cause Floods" by Prof T.A. Rafter

January 23, 1957 – New Zealand scientist warns about consequences of carbon dioxide build-up

allouryesterdays.info/2023/01/22/j...

Spiralling global temperatures (1850-2025)

The last 3 years really jump out, rather like 2015-6 did when we first produced this graphic back then. Now, 2015-6 looks rather cool...

More on the spiral: doi.org/10.1175/BAMS...

Submissions for abstracts to EGU26 are open until next week.

@imenke.bsky.social , @etheokritoff.bsky.social , Noah Walker-Crawford, @rosapietroiusti.bsky.social , and I are looking forward to your contributions to our climate science and litigation-themed outreach session.

Front page of the first CO2 Newsletter, October 1979. Image of a Keeling Curve and then an explanation "Why the CO2 Newsletter?"

CO2 Newsletter Vol. 1 no. 1 (Oct 1979) is live!

Between 1979 and 1982 American geologist William N. Barbat published 18 issues. Each was 8 pages of news (scientific abstracts, testimony, science and policy reports) editorials, investigations etc.

1/2

allouryesterdays.info/2026/01/05/c...

December 24, 1968 - "Earthrise" photo - All Our Yesterdays On this day, December 24 in, 1968 the Earthrise photo showed our pale blue dot for what it is. [The amount of carbon dioxide in the atmosphere was 323ppm. At time of writing it was 419ishppm- but for ...

December 24, 1968 – “Earthrise” photo

allouryesterdays.info/2022/12/23/d...

And Christmas came early: Asmania et al took an important hurdle in their lawsuit against carbon major Holcim, which was today admitted to proceed to trial. Noone is above the law!

“Playing the market”, but for real.

⚖️ Are you working on topics that could be relevant for climate litigation?

➡️ Submit an abstract to our outreach session (which allows you to submit a second abstract)
#EGU26

meetingorganizer.copernicus.org/EGU26/sessio...

目标类型及描述。争取到 2035 年温室气体排放水平稳
中有降，比 2030 年下降 5%以上。

"Target type and description: Strive to achieve a stable to slightly reduced level of greenhouse gas emissions by 2035, with a decrease of more than 5% compared to 2030."

(Google Translated.)

very interesting! it might be worth it to consider renewables, too. their energy density is much lower comparing to fossil fuels, and i would assume that the ownership structures are also more local, less concentrated. this asymmetry would be very interesting to grasp

I've finally got around to curating a selection of films about the #climate crisis 🎥

There's lot of mediocre climate films out there, but for me these stand out head & shoulders above the rest 🎞️

They make excellent resources for classrooms, lecture halls, or community cinema's 🎬

Thread:🧵Plz RT

This is how climate injustice unfolds. There is both an economic logic to cutting emissions now & a moral imperative to rapidly scale up international finance for loss and damage and adaptation in the most vulnerable countries.

🚨 BREAKING: The European Court of Human Rights @ECHR_CEDH has ruled in @GreenpeaceNorge and Others v. Norway.
The decision is an important step for #ClimateJustice.

Here’s why it matters 🧵

Our new brief “Pre-COP30: how are temperatures tracking on the latest targets?” is here: www.climate-resource.com/reports/ndcs...
#ClimateAction #COP30 #ClimateFinance

Multi-century global and regional sea-level rise commitments from cumulative greenhouse gas emissions in the coming decades - Nature Climate Change It is important to understand how much long-term sea-level rise is already committed due to historical and near-term emissions. Here the authors use a modelling framework to show how decisions on glob...

Really important paper led by my @iiasa.ac.at colleague Alex Nauels www.nature.com/articles/s41...
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏

Merz & Co wollen die EU-Klimaziele aufweichen?! Nicht mit uns 😡 In einem offenen Brief mit Wissenschaftler*innen fordern wir die Bundesregierung jetzt auf, sich für ein starkes Ziel von mind. 90% Reduktion bis 2040 einzusetzen & nicht noch zu verzögern!
👉 fridaysforfuture.de/offener-brie...

A request for weather interested volunteers!

Met Eireann would like to rescue millions of weather observations taken in Ireland over many decades that are still stuck on paper. #WeatherRescue

Anyone can help: www.zooniverse.org/projects/met...

This is a good corrective to the BS narrative flowing through the Pielke/AEI/NYP/EID/DOE nexus. Their argument is designed so that we can never ever attribute extreme events to emissions - even singular events that would have *never* [for some suitable finite approximation] have happened before.

Overshoot: Exploring the implications of meeting 1.5C climate goal ‘from above’ - Carbon Brief The first-ever international conference on the contentious topic of “overshoot” was held last week in...

Super comprehensive report on our @iiasa.ac.at overshoot conference by @carbonbrief.org. Great summary and overview on some of the central discussion points. Check it out👇👇👇
www.carbonbrief.org/overshoot-ex...

River or sankey diagram showing the allocation of profits from global oil and gas companies to quantiles of the US wealth size distribution via financial system intermediaries, such as asset managers, and categories of ultimate beneficiaries, such as business owners, pension funds and shareholders in listed companies. The scale is hundreds of billions of US dollars, and ultimately 50.4% of profits reaching the US personal wealth distribution go to the richest 1% of households.

🚨NEW PAPER🚨
We all know the 2022 energy price shock fueled the cost of living crisis. It also caused a profit bonanza for the very rich. We show the US reaped the largest profits ($377bn) of any country. 50% went to the richest 1%, only 1% to the bottom 50%. A🧵 www.sciencedirect.com/science/arti...

Episode 2: Highest Possible Ambition under Overshoot with Joeri Rogelj

In the lead up to the Overshoot Conference @iiasa.ac.at Sep 30-Oct 2, the organizers had a fantastic nerdy idea to get the leading experts in their fields share their perspectives on the key themes. Highly recommend for your daily commute, background to cooking etc.: open.spotify.com/show/5MpXqh1...

⚡ ⚖️ 🌐 upcoming #𝐂𝐥𝐢𝐦𝐚𝐭𝐞𝐋𝐢𝐭𝐢𝐠𝐚𝐭𝐢𝐨𝐧: Asmania v. Holcim
Crucial hearing upcoming in Switzerland, this could set a precedent for holding climate polluters accountable.
📅 Wed, 3 Sept 2025 – starting at 8:30 am CEST
📍 Cantonal Parliament of Zug🇨🇭
👇 A brief thread🧵

🔥 Just published! 🔥
Our new manuscript on global #wildfires look beyond burned areas and ask:
What drives the #economic damages of wildfires — now & in the future?
We find that socioeconomic vulnerability, not just #climate, is key.
📄 iopscience.iop.org/article/10.1...
(Highlights below ⬇️)

*** Faktencheck***
In der Generaldebatte im Bundestag sprach Bundeskanzler Friedrich #Merz auch zum Klimaschutz. Er sagte:
"Selbst wenn wir alle morgen klimaneutral wären, würde keine einzige Naturkatastrophe weniger geschehen". Ein Faktencheck.
1/

Causal pathway from AMOC to Southern Amazon rainforest indicates stabilising interaction between two climate tipping elements - IOPscience Causal pathway from AMOC to Southern Amazon rainforest indicates stabilising interaction between two climate tipping elements, Högner, Annika, Di Capua, Giorgia, Donges, Jonathan F, Donner, Reik V, Feulner, Georg, Wunderling, Nico

New study out, in which we detect a causal link in reanalysis+observational data from an AMOC SST index to the Southern Amazon rainforest: dry season precipitation increases when the AMOC weakens.

doi.org/10.1088/1748...

🌎 New research led by IIASA researcher @hoegner.bsky.social shows a link between two major climate tipping elements: the Southern Amazon rainforest and the Atlantic Meridional Overturning Circulation (AMOC).

👉 iiasa.ac.at/news/jun-202...
@pik-potsdam.bsky.social @ioppublishing.bsky.social