Intempéries

Here, we show that the Last Glacial Maximum (LGM) provides a stronger constraint on equilibrium climate sensitivity (ECS), the global warming from increasing greenhouse gases, after accounting for temperature patterns. Feedbacks governing ECS depend on spatial patterns of surface temperature (“pattern effects”); hence, using the LGM to constrain future warming requires quantifying how temperature patterns produce different feedbacks during LGM cooling versus modern-day warming. Combining data assimilation reconstructions with atmospheric models, we show that the climate is more sensitive to LGM forcing because ice sheets amplify extratropical cooling where feedbacks are destabilizing. Accounting for LGM pattern effects yields a median modern-day ECS of 2.4°C, 66% range 1.7° to 3.5°C (1.4° to 5.0°C, 5 to 95%), from LGM evidence alone. Combining the LGM with other lines of evidence, the best estimate becomes 2.9°C, 66% range 2.4° to 3.5°C (2.1° to 4.1°C, 5 to 95%), substantially narrowing uncertainty compared t

Au moins 50 personnes sont mortes cette semaine en raison des fortes intempéries hivernales qui frappent les Etats-Unis, ont annoncé vendredi les autorités et les médias locaux.

Invité à s’exprimer lors d’une table ronde en compagnie de Patrick Pouyanné, PDG de Total, le climatologue Jean Jouzel revient sur cette expérience amère dans les Echos. Les échanges illustrent bien l’écart entre scientifiques et patrons.

Permafrost and glaciers in the high Arctic form an impermeable ‘cryospheric cap’ that traps a large reservoir of subsurface methane, preventing it from reaching the atmosphere. Cryospheric vulnerability to climate warming is making releases of this methane possible. On Svalbard, where air temperatures are rising more than two times faster than the average for the Arctic, glaciers are retreating and leaving behind exposed forefields that enable rapid methane escape. Here we document how methane-rich groundwater springs have formed in recently revealed forefields of 78 land-terminating glaciers across central Svalbard, bringing deep-seated methane gas to the surface. Waters collected from these springs during February–May of 2021 and 2022 are supersaturated with methane up to 600,000 times greater than atmospheric equilibration. Spatial sampling reveals a geological dependency on the extent of methane supersaturation, with isotopic evidence of a thermogenic source. We estimate annual methane emissions from prog

Le patron de l’ONU, António Guterres, a comparé lundi l’inaction des pays de la planète face à la crise climatique à un “suicide collectif”. Comme certains dirigeants de pays vulnérables, il a appelé à “revoir” le fonctionnement du système financier international afin de pouvoir mieux aider certains pays victimes de catastrophes.

Patagonian ice fields are among some of the fastest-melting glaciers on the planet. As these glaciers disappear, the earth that once lay beneath them is rebounding upwards at rates much faster than expected.