Newly Discovered Molecules May Cool Warming

Criegee biradicals eat SO2 and NO2, produce clouds

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. They were isolated using a hi-tech particle accelerator at America's Lawrence Berkeley National Laboratory.

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 molecules, known as chemical ‘intermediates’, should have a significant influence on climate. However, until now they have never been directly observed.
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 These compounds will lead to aerosol formation and ultimately to cloud formation with the potential to cool the planet. The research is reported today in the journal Science. Study leader Dr Carl Percival, from the University of Manchester, said: ‘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.’

Co-author Professor Dudley Shallcross, from the University of Bristol, pointed out that chemicals released naturally by plants aided the production of Criegee biradicals. ‘Natural ecosystems could be playing a significant role in off-setting global warming,’ he said.

While this sounds very nice, I urge a little caution.  At this point in time aerosol formation is what it is, and if the Criegee molecules exist, and are causing cloud formation, that's already part of our observations.  Now, cloud formation, and the effects of cloud are perhaps the greatest wild card outstanding in global climate models, and to find something that influences this is a great advance, but to sell it as the "solution" to global warming (a problem I'm not convinced is real in any event, at least on the globe killing scale) is unwarranted.