Our atmosphere is a turmoil of chemical activity, says Prof. Dudley Shallcross of Bristol University. Some of the most powerful agents of change are molecules so short-lived that they have only been discovered in recent years. Formed when gases from plants react with ozone, they attack nitrogen and sulphur pollutants and turn them into fine aerosols which screen against the sun. What might this mean for atmospheric pollution and for climate change?
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