Climate crisis – atmospheric memory: memory of the rain

This spring is not a good thing for people who suffer from climate fear. While some friends grumble, it should finally get warm (!), Others only see the soil dusty for weeks and months. After all, the trees still shine in the bright spring green. And for those who appear too cold: Yes, according to the German Weather Service (DWD) it was 0.5 degrees colder in the first half of May than on average from 1991 to 2020. Compared to the reference period from 1961 to 1990, however, it was almost 0.5 degrees too warm. We have got used to global warming so much that, admittedly, these seem normal temperatures in the spring.

The missing rain, however, also causes the freezing friend. According to the official figures, the spring 2025 threatens to set up an all -time record in terms of dryness. From March to mid -May, only around a third of the usual precipitation quantity fell from March to 58 millimeters. If something does not come from the sky in the next two weeks, it will be the driest spring since the beginning of the weather records in 1893. It may be that all of this is still weather and not the result of a climate trend. However, it looks threatening. Especially when one lead -gray cloud after another pushes over the sky without sending anything from its substance to earth. What if the clouds had simply forgotten how rain goes, the person suffering from climate fears wonders to scold themselves for their silly thoughts. Because what has no memory – an agglomeration of water vapor – cannot forget anything. Or?

In a recent study, Anja Katzenberger and Anders Levermann from the Potsdam Institute for Climate Impact Research (PIK) have identified a “physical memory” of the atmosphere, which determines the rhythm of the monsoon rain. This usually starts in spring and ends in autumn. A certain difficulty seems to be in the weather to switch from one weather: “It is already raining, then the rain gets itself. But if it has been dry for a long time, then it is difficult to get the rain going,” writes the PIK. The change is abruptly, as if a switch is being passed on. The climate researchers speak of a “bistable behavior”. The switch of the switch is 35 kilograms of water vapor per square meter. As far as the monsoon remembers this tipping point, it should rain reliably every year – and the rain stop again. However, there are risk factors that could disturb the memory of the atmosphere. The general global warming, for example, because of which the air stores more moisture, which could shift the tilting point – follow with still unknown.

The “memory of the atmosphere” is a nice metaphor. And the memory of the people: How was that again with the climate goals?