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Pierre Friedlingstein

Pierre Friedlingstein is Professor and Chair in Mathematical Modelling of the Climate System at the University of Exeter, and Research… more

Pierre Friedlingstein
H-index: 135
Environmental science 58%
Geography 17%
The land sink always declines during an El Niño. Warmer/dryer tropics reduce the sink.
I agree. No evidence the ocean did shut down in 2024 as far as I know. Maybe @gwagner.com can explain ?
2024 was an El Niño. So higher growth rate was expected, but not that high.
Main reasons are fires, esp. in the tropics and overall land sink strongly reduced. Ocean sink did not shut down.
More on this mid November with the global carbon budget 2025 release.
👏
The attack on @frediotto.bsky.social was seeded years ago by Roger Pielke Jr, who started arguing that this table from a recent @ipcc.bsky.social report proved that climate science cannot attribute extreme weather to climate change.

But Roger is of course lying. And we know this for 2 reasons.

🧵
CLIMATEWIRE
Climate critics try to discredit IPCC author for linking
disasters to global warming
By LESLEY CLARK, SARA SCHONHARDT, CHELSEA HARVEY | 10/09/2025
06:22 AM EDT Roger Pielke Jr. and oil industry supporters are attacking climate scientist Friederike Otto, whose
work has been used in lawsuits against polluters. Table 12.12 | Emergence of CIDs in different time periods, as assessed in this section. The colour contesponds to the confidence of the region with the highest confidence: white cells indicate where evidence is lacking or the signal is not present, leading to overal bu confidence of an emerging signal.
The attack on @frediotto.bsky.social was seeded years ago by Roger Pielke Jr, who started arguing that this table from a recent @ipcc.bsky.social report proved that climate science cannot attribute extreme weather to climate change.

But Roger is of course lying. And we know this for 2 reasons.

🧵
CLIMATEWIRE
Climate critics try to discredit IPCC author for linking
disasters to global warming
By LESLEY CLARK, SARA SCHONHARDT, CHELSEA HARVEY | 10/09/2025
06:22 AM EDT Roger Pielke Jr. and oil industry supporters are attacking climate scientist Friederike Otto, whose
work has been used in lawsuits against polluters. Table 12.12 | Emergence of CIDs in different time periods, as assessed in this section. The colour contesponds to the confidence of the region with the highest confidence: white cells indicate where evidence is lacking or the signal is not present, leading to overal bu confidence of an emerging signal.
If you can’t refute the message, attack the messenger !
🤬
I hope he doesn’t mean his last sentence…
CCS can only reduces emissions, with CO₂ being captured before being released to the atmosphere and then stored underground.
To remove CO₂ from the atmosphere one needs CDR (such as DAC, afforestation, BECCS, …).
Light by a long way. Not that many people still use candles! 😉
A bit saddening that speaking the truth about science is now seen as potentially incompatible with being non partisan…

But you are making the right choice. Pretty much any one could be a provost but only Michael Mann can be Michael Mann 😉
Yep I fully agree Ben.
Given the current political landscape across the world, the idea of a responsible global governance on SRM is extremely naive.
En comparaison avec une marée noire suite au naufrage d’un pétrolier, y a pas photo 😉
How about speeding up the phase-out of fossil fuel?
Period.
That probably won’t ever happen in our life time, so CO₂ forcing will probably always dominate.
I agree with Michael here. Current CO₂ induced warming is about 50% larger than CH₄.
For current CH₄ emissions, atmospheric CO₂ should drop significantly below 400ppm. That won’t happen in the coming decades.
Il faut réduire les émissions de bcp plus que ça et de manière soutenue pendant des années pour voir un signal sur le CO₂ atmosphérique qui sort du bruit.
Du coup -6% d’émission anthropique, 35 au lieu de 37 GtCO₂ émis par l’homme induirait une baisse du taux de croissance du CO₂ d’environ 0.1ppm. Bien inférieur à la variabilité naturelle, donc indétectable.
La variabilité d’une année à l’autre est entièrement due aux puits biosphériques, et à leur réponse à la variabilité du climat : El Nino = puits plus faibles = taux de croissance plus élevé.
Rien à voir avec les émissions anthropiques qui varient très peu d’une année à l’autre
Vous avez entendu parlé de la variabilité interannuelle du climat et du cycle du carbone ?
Regardez ce graphe qui montre le taux de croissance annuel du CO₂.

gml.noaa.gov/webdata/ccgg...
gml.noaa.gov
C’est vous qui avez parlé de net zéro (=réduction de 100%)…
Net zéro est clairement pas trivial mais pas impossible.

Apres si on émet deux fois moins de CO₂ le réchauffement est réduit d’autant. Actuellement on est à 0.25C/décennie.
Passer à 0.1C serait un grand pas dans la bonne direction
CNRS @cnrs.fr · Sep 9
To rehabilitate the general view of women's contributions to the history of science, the CNRS is part of a commission that aims to inscribe the names of 72 female scientists on the Eiffel Tower. 🗼 #WomenInScience
Women scientists to be showcased on the Eiffel Tower soon
To rehabilitate the general view of women's contributions to the history of science, the CNRS is part of a commission that aims to inscribe
www.cnrs.fr
Quand au Covid, comme déjà répondu, les émissions anthropiques n’ont diminué que de 6% en 2020 (35 vs 37 milliards de tonnes de CO₂). Pas assez pour avoir un impact quelconque,en un an, sur le CO₂ atmosphérique ou la température globale.
Non le réchauffement s’arrête (plus on moins ~10%) quand les émissions de CO₂ s’arrêtent. Si les émissions anthropiques s’arrêtent, la concentration de CO₂ diminue de qui compense l’inertie thermique du système climatique.
Il y a pas mal de papiers scientifiques qui ont montré ca depuis 10-15 ans.
Globalement le réchauffement s’arrête quand les émissions s’arrêtent.
Mais en effet tant qu’on continue à émettre des gaz à effet de serre (même en quantité décroissante), la température continuera à augmenter.
Mais limiter le réchauffement sous 2C est encore possible.

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