In what scientists are describing as a potential breakthrough for global warming, they have found that a molecule in the earth’s atmosphere could cool the planet.
According to a paper published in
Science, researchers from
The University of Manchester,
The University of Bristol and
Sandia National Laboratories, say invisible chemical intermediaries called
Criegee biradicals have the revolutionary potential to offset
climate change.
Cool the planet
Criegee biradicals are powerful oxidisers of pollutants such as nitrogen dioxide and sulfur dioxide, produced by combustion. As such, they act as natural atmospheric 'cleaners’. Scientists believe that, with further
research, these molecules could cool the planet. Moreover, because they come from chemicals released naturally in plants, they say nature itself could be the agent offsetting global warming.
"The point here is that the Criegee biradical is already part of the Earth system story, it is made when alkenes released by bio-organisms (particularly plants) reacts with ozone," Dr Carl Percival, reader in Atmospheric Chemistry at The University of Manchester and one of the authors of the paper, said.
Synchroton
First hypothesised in the 1950s, Criegee biradicals have until now not been detectable. But thanks to a machine, designed by Sandia researchers, which uses light from a third-generation synchrotron facility, these previously undetected chemical intermediaries can be seen and measured in terms of how fast they react.
Through the synchrotron researchers found that the Criegee biradicals react more rapidly than first thought and will accelerate the formation of sulphate and nitrate in the atmosphere. These compounds will lead to aerosol formation and ultimately to cloud formation with the potential to cool the planet, the authors of the paper say.
"Criegee radicals have been impossible to measure until this work carried out at the Advanced Light Source. We have been able to quantify how fast Criegee radicals react for the first time," Dr Carl Percival said. "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.
"The main source of these Criegee biradicals does not depend on sunlight and so these processes take place throughout the day and night."
Geo-engineering
The findings are potentially significant in the face of growing concerns that not enough action is being taken to keep global temperatures below two degrees Celsius – the threshold above which scientists warn we risk catastrophic climate change.
Because of this, there are increasing calls for support of technologies that extracts carbon emissions from the atmosphere, know as geo-engineering. But there are concerns that such technologies, which include reflecting sunlight into space, could bring with them significant risks.
Professor Dudley Shallcross, Professor in Atmospheric Chemistry at The University of Bristol, said one of the attractions of the Criegee biradicals was that they could do their work via natural ecosystems.
"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," he said.
Dr Carl Percival, added: "From a geo-engineering viewpoint, production and release of Criegee biradicals is a non-starter. Apart from the fact that we have only just begun to characterise their reactivity, predominantly the species to control is NOx to avoid ozone/smog episodes."
Like this content? Please subscribe to our free weekly e-newsletter at the top of the page for more content like this.
Related content:
