Reason for 2023 heat extremes suggests 1.5°C could be reached sooner than expected
From Cosmos (6/12/24)…
Reason for 2023 heat extremes suggests 1.5°C could be reached sooner than expected
Scientists confounded by the rapid onset of extreme temperatures last year believe they have identified a previously unidentified driver.
One expert says the problem suggests the planet may exceed the 1.5°C Paris Agreement target sooner than forecast.
In 2023 the global average temperature soared to almost 1.5°C above the preindustrial level, setting several new records. And deeply concerning atmospheric scientists.
Now, new climate modelling research has identified a previously unknown driver of this sudden increase: a record low “planetary albedo” – the percentage of incoming solar radiation that is reflected out to space.
They found it was due to reduced low cloud cover.
This effect accounts for 0.2°C of 2023’s warming, which has not been satisfactorily explained before.
Considering the globe as a whole, high clouds and cloud-free scenes result in warming of the Earth’s atmosphere, as less energy escapes into space than arrives from the sun. For low clouds, it’s the opposite, so their decline leads to warming. Credit: Alfred-Wegener-Institut/Yves Nowak
