University of Maryland: Global Warming
Global Warming Fix Would Damage Earth's Protective Ozone Layer - 09/25/08
An international team of scientists, including University of Maryland Professor Ross Salawitch, say that a widely-discussed idea to offset global warming by injecting sulfate particles into the stratosphere would significantly damage Earth's protective ozone layer.
he study, by Simone Tilmes of the National Center for Atmospheric Research (NCAR), Rolf Müller of the German Research Center Jülich, and Ross Salawitch of the University of Maryland was published April 24 in Science Express, the on-line version of Science, in advance of its publication in Science. They warn that this artificial attempt to cool the planet could destroy between one-fourth and three-fourths of the ozone layer above the Arctic, delay the recovery of the Antarctic ozone hole by as much as 70 years, and cause ozone thinning in mid-latitude regions.
Tilmes, Müller, and Salawitch studied the effects of the Mount Pinatubo eruption, analyzed the chemical actions of sulfur in the atmosphere, and modeled the potential impact of an attempted geoengineering effort.
They found that adding sulfur to the atmosphere would spark chemical reactions leading to the liberation of chlorine, a compound known to destroy ozone, with the largest effects felt during winters when the Arctic stratosphere was particularly cold.
"Adding sulfur to the stratosphere would undo our efforts of the past two decades to restore the ozone layer," says Dr. Salawitch, who was involved in studies that helped support the Montreal Protocol, the landmark international treaty passed in 1987 which restricted the industrial production of CFCs (chlorofluorocarbons) and other ozone depleting substances.
Dr. Salawitch, who is a professor with UM's Departments of Chemistry and Biochemistry, as well as Atmospheric and Oceanic Science, and the Earth System Science Interdisciplinary Center, contributes expertise to a variety of atmospheric composition and climate change research projects led by NASA, and participated in the Intergovernmental Panel on Climate Change, which together with Al Gore won the 2007 Nobel Peace Prize for its efforts to build and disseminate greater knowledge about climate change.
