Scientists have always known about invisible molecules called Criegee biradicals in the atmosphere, but now they know how they react with pollutants.

The chemical intermediates are powerful oxidizers of pollutants like nitrogen and sulfur that naturally clean the atmosphere - forming aerosol and eventually clouds, according to a new study published in the journal Science.

Aerosols play a key role in reflecting solar radiation back into space, and knowing how Criegee biradicals react with pollutants to form them could play a major role in off-setting climate change.

Our results will have a significant impact on our understanding of the oxidizing capacity of the atmosphere and have wide ranging implications for pollution and climate change, said Dr. Carl Percival from the University of Manchester.

Percival noted that using their discovery to engineer aerosols and proactively cool the Earth is still beyond scientific capabilities, but stressed the need to preserve the ecosystem that naturally produces Criegee biradicals.