As if greenhouse gasses that cause climate change weren’t bad enough, scientists have discovered a new category of uncontrolled chemicals that are depleting the ozone layer and affecting the Earth’s climate. Phys.org reports that a new study recently publishing in the journal Nature Geoscience reveals chemicals not controlled by a United Nations treaty, known as ‘very short-lived substances’ (VSLS), are leading to further depletion of the ozone layer.
According to study lead author Dr. Ryan Hossaini of the University of Leeds, “VSLS can have both natural and industrial sources. Industrial production of VSLS is not controlled by the United Nations Montreal Protocol because historically these chemicals have contributed little to ozone depletion. But we have identified now that one of these chemicals is increasing rapidly and, if this increase is allowed to continue, it could offset some benefits to the ozone layer provided by the Montreal Protocol.”
Hossaini and the other researchers used a 3D computer model of the atmosphere to investigate the impact of VSLS on ozone and climate, using VSLS measurements over the past two decades that were provided by the National Ocean and Atmospheric Administration (NOAA), which participated in the study. The chemical in question found by the researchers is called dichloromethane, a man-made VSLS which is used in many different industrial processes.
According to study co-author Professor Martyn Chipperfield of the University of Leeds, “ The presence of increasing dichloromethane will lead to uncertainty in our future predictions of ozone and climate.” While the researchers found the amount of ozone depletion being caused by VSLS is small compared to other gasses like CFCs, they found ozone depletion driven by VSLS was about four times more efficient at influencing climate.