Elusive molecules in the Earth’s atmosphere may be helping to cool the planet more efficiently than scientists previously thought, a new study suggests.
They are called Criegee intermediates, or Criegee biradicals (named after the German chemist Rudolf Criegee), and are short-lived molecules that form in the Earth’s atmosphere when ozone reacts with alkenes (a family of organic compounds). While scientists have known about the intermediates for decades, they haven’t been able to directly measure how the molecules react with other atmospheric compounds, such as the pollutants nitrogen dioxide and sulfur dioxide, until now.
Researchers used a new method to create Criegee intermediates in the lab, and then reacted them with several atmospheric compounds. They found that the reactions with the pollutants could produce aerosols, tiny particles that reflect solar radiation back into space, much more quickly than previously assumed.