A little-understood molecule in the atmosphere could play an important role in reducing pollution and global warming, scientists believe. The 'Criegee biradicals' could lead to aerosol formation - and ultimately to clouds, with the potential to cool the planet. The compounds react far more rapidly than scientists expected. Criegee biradicals were first hypothesised in the 1950s but have only now been isolated and measured. New research shows they act as powerful ‘clean up’ agents, neutralising atmospheric pollutants such as nitrogen dioxide and sulphur dioxide. A byproduct of the process is the creation of aerosol droplets that ‘seed’ planet-cooling clouds. The...