Pollen affects cloud formation and precipitation patterns

"In the Breathing Nature Cluster of Excellence project, we therefore asked whether this effect could be detected outside the laboratory, and how climate change and biodiversity loss affect it," says co-author Professor Johannes Quaas, Professor of Theoretical Meteorology at Leipzig and spokesperson of the Breathing Nature consortium.

Regional and seasonal significance

On a global scale, the effect of pollen on ice formation is relatively small compared to, for example, dust, but it is significant on a regional and seasonal scale. Particularly in spring, large amounts of pollen are released, rising into the atmosphere and entering cold air layers. Kretzschmar explains: "Because of its size, pollen stays in the atmosphere for only a short time. Our study highlights the importance of smaller pollen fragments, which are produced when pollen ruptures under humid conditions. These smaller particles remain in the air longer and, in sufficient quantities, can enter cold atmospheric layers, where they trigger ice formation."

Climate change intensifies pollen impact -- biodiversity a key factor

Anthropogenic climate change is shifting the start of the pollen season, lengthening it and increasing pollen concentrations in the air. These trends are expected to intensify by the end of the century, which could lead to more frequent and intense local precipitation.

A further aspect of the study is the importance of biodiversity. Many plant species release large amounts of pollen at the same time each spring, which affects cloud formation and the amount of ice particles in the atmosphere. These interactions require further research to better understand the role of pollen in climate evolution and to incorporate this into future climate models. "If we can correctly simulate the effect of pollen and how it interacts with the climate, we will be able to make more accurate predictions," says Kretzschmar.