Newly discovered molecule has potential to offset climate change and cool the planet

Researchers claim a newly discovered molecule found in the Earth's atmosphere holds the potential to help offset global warming by actually cooling the planet. The molecule is a Criegee biradical or Criegee intermediate, which are chemical intermediaries that are powerful oxidizers of pollutants produced by combustion, such as nitrogen dioxide and sulfur dioxide. They have the ability to naturally clean up the atmosphere by helping break down nitrogen dioxide and sulfur dioxide to form sulfate and nitrate, which ultimately leads to cloud formation that could help cool the planet.

Criegee biradicals are carbonyl oxides that were first hypothesized in the 1950s by Rudolf Criegee but had not been able to be directly detected until now. Using a unique apparatus designed by Sandia Lab researchers, researchers from the University of Manchester, Bristol University and Sandia Labs were able to detect the Criegee biradical - in this case formaldehyde oxide (CH₂OO) - and measure how fast it reacts.

The apparatus used the intense, tunable light from a third-generation synchrotron facility at the Lawrence Berkeley National Laboratory's Advanced Light Source to discern the formation and removal of different isomeric species, which are molecules that contain the same toms but arranged in different combinations.

The researchers found that Criegee biradicals react much faster than initially thought and will accelerate the formation of sulfate and nitrate from sulfur dioxide and nitrogen dioxide in the atmosphere. They say that these compounds will lead to aerosol formation and ultimately cloud formation, which has the potential to cool the planet.

"Our results will have a significant impact on our understanding of the oxidizing capacity of the atmosphere and have wide ranging implications for pollution and climate change," said Dr Carl Percival, Reader in Atmospheric Chemistry at The University of Manchester and one of the authors of the paper. "The main source of these Criegee biradicals does not depend on sunlight and so these processes take place throughout the day and night."

"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," added Professor Dudley Shallcross, Professor in Atmospheric Chemistry at The University of Bristol.

The researcher team's paper, which is published in Science, describes a new means of producing gas-phage Criegee intermediaries, which they used to prepare enough CH2OO to allow measurements of its reactions with water, sulfur dioxide, nitric oxide and nitrogen dioxide. It is this ability to reliably produce Criegee intermediaries that the team says will facilitate future research that could allow these molecules to play a major role in off-setting climate change.

Below is a video from Sandia Labs with Sandia combustion researchers Craig Taatjes and David Osborn discussing the research.