Topic
Thresholds in the climate system—like AMOC slowdown, ice-sheet loss, or Amazon dieback—beyond which change becomes abrupt and potentially irreversible.
UNEP now accepts the overshoot and describes a way back to 1.5C by 2100 that needs global emissions halved by 2035 and then removal running at a scale one outside researcher puts at 100,000 times today's.
Perspective Coverage
5 publishersReality
An ESA-led team pooled 45 surveys from 27 satellites to weigh Greenland and Antarctica back to the 1970s. It finds 11.3 trillion metric tons of ice gone since 1979, five-sixths of it to water working from below.
Reality
Bernardo Flores says warming has already reached the first of those two conditions, and the El Nino now strengthening is likely the strongest on record, arriving in a basin where at least 40% of the forest is estimated to be degraded.
Reality
An ALLFED preprint ran two 100-year simulations under 2C of warming, one with the Atlantic circulation forced down and one left alone, then layered wheat, maize and rice models on top of both. It has not been peer reviewed.
Reality
A Nature Climate Change study finds the same warming that leaves Atlantic currents intact near 5.5C if reached slowly can tip them at 2C at today's emissions rate.
Reality
New work in Nature Geoscience finds past Atlantic slowdowns raised the heat stored by the global ocean, an effect the authors size at about 25 ppm of carbon dioxide.
Reality