New-found particle could help cool Earth

Posted by Kate Taylor

A long-hypothesized particle which could cool the planet by cleaning up the atmosphere has finally been discovered.

Researchers from the University of Manchester, the University of Bristol and Sandia National Laboratories say that Criegee biradicals are powerful oxidisers of pollutants such as nitrogen dioxide and sulfur dioxide, produced by combustion.

Sandia researchers detected the particles using light from a third-generation synchrotron facility at the Lawrence Berkeley National Laboratory's Advanced Light Source.

The intense, tunable light from the synchrotron allowed researchers to distinguish different isomeric species – molecules that contain the same atoms but arranged in different combinations.

And the team found that the Criegee biradicals react more rapidly than first thought, accelerating the formation of sulphate and nitrate in the atmosphere. These compounds lead to aerosol formation and ultimately to cloud formation, giving them the potential to be used in geoengineering projects aimed at cooling the planet.

 and one of the authors of the paper, believes there could be significant research possibilities arising from the discovery of the Criegee biradicals.

"We have been able to quantify how fast Criegee radicals react for the first time. Our results will have a significant impact on our understanding of the oxidising capacity of the atmosphere and have wide ranging implications for pollution and climate change," says Dr Carl Percival, reader in atmospheric chemistry at the University of Manchester.

"The main source of these Criegee biradicals does not depend on sunlight and so these processes take place throughout the day and night."

Indeed, Criegee biradicals may already be having a cooling effect on the planet.

"A significant ingredient required for the production of these Criegee biradicals comes from chemicals released quite naturally by plants, so natural ecosystems could be playing a significant role in off-setting warming," says Professor Dudley Shallcross, professor in atmospheric chemistry at the University of Bristol.