
Trillions of bacteria, fungi, viruses, and single-celled organisms travel through the atmosphere, creating an invisible ecosystem, called the aerobiome, that affects both weather and human health.
Recent studies show that every year, a trillion trillion bacterial cells and about 50 million tons of fungal spores rise from the land and sea into the sky. Carried by wind, forest fires or water vapor, these microorganisms can travel thousands of kilometers before falling back to earth.
In France, on the Puy de Dôme mountain, scientists have discovered that every millimeter of cloud water contains up to 100,000 living cells. So far, over 28,000 species of bacteria and 2,600 species of fungi have been identified, many of them previously unknown to science.
Experts point out that these microbes are not just random passengers in the clouds. They can influence how raindrops form, the spread of diseases, and the circulation of vital elements in nature.
"Clouds are not just water and vapor. They are living habitats that travel above our heads every day," says aerobiologist Pierre Amato, one of the leading researchers in the field.
The findings open a new field of research into how this "invisible aerial ecosystem" may affect the global climate and people's daily lives.