A new molecule might help in our fight against global warming. The new molecule, called a Criegee biradical, can convert pollutants nitrogen dioxide and sulphur dioxide into nitrate and sulphate that lead to the creation of aerosol droplets that then create cloud cover that cools the planet. Criegee biradicals were hypothesized by Rudolf Criegee in the 1950s but scientists were only recently able to detect them. Researchers published their discovery in this week’s issue of Science.
Scientists have already warned that measures to stop the warming of Earth are simply not happening fast enough to halt the possible rise in sea levels. Energy efficiency just won’t cut it. We need to move on to adaption or find more radical ways to stop what is fast appearing to be inevitable. In the last Century the Earth's average surface temperature increased by about 0.8 degrees Celsius with two thirds of the increase occurring in just the last 30 years.
The scientists from the University of Bristol and Snadia National Laboratories used an intensely powerful light—100 times stronger than the sun—to detect the biradicals. And found that they had the ability to oxidize sulfur dioxide, which eventually turns into sulphuric acid, which has a cooling effect.
The greatest cooling effect could be potentially felt in areas where there are high concentrations of alkenes and pollutants, which allow the biradicals to react. The production of such biradicals happens quite naturally, from chemicals released by plants. And the biradicals do not depend on sunlight so the process can take place at any time.
The question is though, how many of such naturally occurring biradicals would we need to make a cooling impact on Earth?
We do know from volcanic eruptions, such as when Mount Pinatubo in the Philippines erupted nearly two decades ago, sulphur dioxide can create a cover of sulphuric acid that reduces the sunlight sometimes by 10 percent, and over a period of two years leads to a decrease in temperatures around the globe by 0.5 degrees Celsius. On the down side such explosions cause lung illness, acid rain and the depletion of the ozone layer. It remains to be seen if there are any serious downsides to a large increase in Criegee biradicals.