part of current warming is unexplained

The climatologistclimatologist in chief of the NasaNasa admits: part of the extreme global warming which has lasted since March 2023 is unexplained. “ As climate scientists, the year 2023 has forced us to be more humble, but also made us even more worried. It must be admitted that no other year has challenged our climate predictions as much as 2023, Gavin Schmidt admitted. Our forecast for 2023 is off by 0.2°C, which doesn’t sound like much, but it’s actually huge ».

All known warming factors are not enough to explain the current peak

However, the causes of very strong global warming in 2023 and 2024 seemed well determined until now: the essential role of broadcastsbroadcasts of greenhouse gases from human activities, the climatic phenomenon The ChildThe Child (June 2023 – May 2024) which has a warming effect, the modification of the laws concerning pollution emitted by large ships (which allowed the sky to be clearer, and the sea to suffer even more warming), the water vapor emitted by the eruption of the Hunga Tonga volcano in the Pacific Ocean, a phase of the solar cycle which does not help…

But apart from the consequences of human emissions of greenhouse gases on the rise in temperatures (which are not called into question, their role remaining major), the climatologist explains to the newspaper Yale Environment 360 that the warming linked to the reduction in pollution from ships accounted for 0.05 to 0.08°C, not enough to explain this peak in 2023 and 2024.

Likewise, he specifies that the latest studies carried out on the consequences of the Tonga volcano tend to prove that its cooling power was stronger than its warming power! The current solar cycle is not favorable: over the last 10 years, the quantity of solar rays hitting the Earth has been increasing. The consequences of these rays are poorly understood, but scientists believe they remain minimal. All of this is therefore not enough to explain the incredible acceleration of global warming since the start of 2023.

Forecast models are outdated by current developments

For Gavin Schmidt, there are then two options: “ Either we missed an element that has an impact [qui s’additionne à celui des émissions de gaz à effet de serre, NDLRNDLR]or we just underestimated the vitessevitesse warming “. Is there another phenomenon that contributes to warming the climate that we do not yet know about? Or did El Niño have a stronger impact than expected? It’s a possibility.

According to a new study published in the journal Sciencethe warming effect of the last El Niño was much stronger than scientists expected. A spectacular jump in temperatures also occurred in 1977 (less strong than 2023 all the same) in the same configuration: after several years marked by La Niña (with a slightly cooling effect), a strong El Niño was triggered and the Planet then suffered a clear increase in warming.

The honesty of one of the world’s leading climate scientists is striking: “ Things are more erratic than we thought. This means that our future predictions may be off the mark. ».

« All our forecasting systems are overwhelmed by climate change », laments Gavin Schmidt.