Newly discovered molecules in atmosphere may offset global warmingBy Muriel Kane
Friday, January 13, 2012
A newly discovered form of chemical intermediary in the atmosphere has the ability to remove pollutants in a way that leads to cloud-formation and could potentially help offset global warming.
The existence of these so-called Criegee biradicals, which are formed when ozone reacts with a certain class of organic compounds, was theorized over fifty years ago, but they have now been created and studied in the laboratory for the first time.
According to Science Daily, the discovery was made possible through the use of a third-generation synchrotron at the Lawrence Berkeley National Laboratory which produces an intense, tunable light that enables scientists to differentiate between molecules which contain the same atoms but arranged in different combinations.
The Criegee biradicals — named after Rudolph Criegee, who postulated their existence in the 1950′s — turn out to react with pollutants, such as sulfur dioxide and nitrogen dioxide, much more rapidly than expected to form sulphates and nitrates. “These compounds,” Science Daily explains, “will lead to aerosol formation and ultimately to cloud formation with the potential to cool the planet.”
One of the authors of the paper describing the discovery, Dr. Carl Percival of the University of Manchester, believes that the results “have a significant impact on our understanding of the oxidising capacity of the atmosphere and have wide ranging implications for pollution and climate change.” He notes that since the compounds which form these molecules are organic in origin, it may mean that “the ecosystem is negating climate change more efficiently than we thought it was.”
The scientists emphasize, however, that they’re a long way off from being able to control the formation of Criegee biradicals themselves, which means that the best thing we can do is preserve the environment so that it can do its job.
Photo by Alex Chupryna *Licanse: GFDL {{GFDL-self}} from Wikimedia Commons
Muriel Kane
Muriel Kane is an associate editor at Raw Story. She joined Raw Story as a researcher in 2005, with a particular focus on the Jack Abramoff affair and other Bush administration scandals. She worked extensively with former investigative news managing editor Larisa Alexandrovna, with whom she has co-written numerous articles in addition to her own work. Prior to her association with Raw Story, she spent many years as an independent researcher and writer with a particular focus on history, literature, and contemporary social and political attitudes. Follow her on Twitter at @Muriel_Kane
Science News
ScienceDaily (Jan. 12, 2012) — Scientists have shown that a newly discovered molecule in Earth's atmosphere has the potential to play a significant role in off-setting global warming by cooling the planet.
Researchers found that 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. (Credit: © Sergey Tokarev / Fotolia)
In a breakthrough paper published in Science, researchers from The University of Manchester, The University of Bristol and Sandia National Laboratories report the potentially revolutionary effects of Criegee biradicals.
These invisible chemical intermediates are powerful oxidisers of pollutants such as nitrogen dioxide and sulfur dioxide, produced by combustion, and can naturally clean up the atmosphere.
Although these chemical intermediates were hypothesised in the 1950s, it is only now that they have been detected. Scientists now believe that, with further research, these species could play a major role in off-setting climate change.
The detection of the Criegee biradical and measurement of how fast it reacts was made possible by a unique apparatus, designed by Sandia researchers, that uses 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 discern the formation and removal of different isomeric species -- molecules that contain the same atoms but arranged in different combinations.
The 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 formation of Criegee biradicals was first postulated by Rudolf Criegee in the 1950s. However, despite their importance, it has not been possible to directly study these important species in the laboratory.
In the last 100 years, Earth's average surface temperature increased by about 0.8 °C with about two thirds of the increase occurring over just the last three decades.
Most countries have agreed that drastic cuts in greenhouse gas emissions are required, and that future global warming should be limited to below 2.0 °C (3.6 °F).
Dr Carl Percival, Reader in Atmospheric Chemistry at The University of Manchester and one of the authors of the paper, believes there could be significant research possibilities arising from the discovery of the Criegee biradicals.
He said: "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.
"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."
Professor Dudley Shallcross, Professor in Atmospheric Chemistry at The University of Bristol, added: "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."
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