Veille 2.1

The Atlantic meridional overturning circulation (AMOC) is an important tipping element in the climate system. There is a large uncertainty whether the AMOC will start to collapse during the century under future climate change, as this requires long climate model simulations which are not always available. Here, we analyze targeted climate model simulations done with the Community Earth System Model (CESM) with the aim to develop a physics-based indicator for the onset of an AMOC tipping event. This indicator is diagnosed from the surface buoyancy fluxes over the North Atlantic Ocean and is performing successfully under quasi-equilibrium freshwater forcing, freshwater pulse forcing, climate change scenarios, and for different climate models. An analysis consisting of 25 different climate models shows that the AMOC could begin to collapse by 2063 (from 2026 to 2095, to percentiles) under an intermediate emission scenario (SSP2-4.5), or by 2055 (from 2023 to 2076, to percentiles) under a high-end emission scenar

Les médias américains se sont entichés d'un nouvel acronyme : "Taco", pour "Trump always chickens out", soit "Trump se dégonfle toujours". Ce simple mot de quatre lettres, inventé par un journaliste du Financial Times, pourrait entraîner de nouvelles secousses sur les marchés financiers. France 24 vous explique pourquoi.

A new study uncovers Earth’s deep temperature history and shows just how tightly carbon dioxide has always controlled the climate

There are significant causes for concern regarding the content of oxygen in the ocean, however. The ocean’s O2 reservoir is vulnerable because it holds less than 1% of the oxygen stored in the atmosphere. In particular, ocean regions with very low or absent oxygen, referred to as oxygen minimum zones, expand as the planet warms,