Microbiology & Virology

Earth’s Atmosphere: A Transport Medium Or An Active Microbial Ecosystem?

By Keith Cowing
Status Report
ISME Journal
June 28, 2024
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Earth’s Atmosphere: A Transport Medium Or An Active Microbial Ecosystem?
Earth’s seas and atmosphere as seen from the International Space Station — NASA

The atmosphere may be Earth’s largest microbial ecosystem. It is connected to all of Earth’s surface ecosystems and plays an important role in microbial dispersal on local to global scales. Despite this grand scale, surprisingly little is understood about the atmosphere itself as a habitat.

A key question remains unresolved: does the atmosphere simply transport microorganisms from one location to another, or does it harbor adapted, resident, and active microbial communities that overcome the physiological stressors and selection pressures the atmosphere poses to life?

Advances in extreme microbiology and astrobiology continue to push our understanding of the limits of life towards ever greater extremes of temperature, pressure, salinity, irradiance, pH, and water availability. Earth’s atmosphere stands as a challenging, but potentially surmountable, extreme environment to harbour living, active, resident microorganisms. Here we confront the current understanding of the atmosphere as a microbial habitat, highlighting key advances and limitations.

We pose major ecological and mechanistic questions about microbial life in the atmosphere that remain unresolved and frame the problems and technical pitfalls that have largely hindered recent developments in this space, providing evidence-based insights to drive future research in this field.

New innovations supported by rigorous technical standards are needed to enable progress in understanding atmospheric microorganisms and their influence on global processes of weather, climate, nutrient cycling, biodiversity, and microbial connectivity, especially in the context of rapid global change.

Null and alternative hypotheses on significant fundamental questions and their implications for atmospheric microbial ecology. Created with BioRender.com.– ISME Journal

The atmosphere: a transport medium or an active microbial ecosystem?, ISME Journal (open access)


Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻