Microbes are everywhere, including in the clouds. Scientific studies are now showing that they play an important role in creating precipitation (reference links to multiple related articles are provided at the end of this article). Microbes from the soil and plants can go airborne and facilitate a process called bio-precipitation. These microbes include bacteria, fungi and tiny algae.
For a cloud to produce precipitation that falls to earth as rain or snow, ice particle formation in the clouds is required. Just a decade ago it was thought that only small mineral particles, or other inert particles, could serve as nuclei for condensation to occur. However, we now know that aerosols in the form of microbes can catalyze ice particle formation that trigger precipitation.
The evidence is building that vegetation and soils are a crucial source of atmospheric biological ice nucleators in precipitation. They may, in fact, be the most efficient ice-forming catalysts in precipitation, not airborne mineral particles. These “rainmaking” microbes are significant influencers of the water cycle. They can also travel long distances in the atmosphere for dispersal on a global scale.