Paper Session III-A - Volcanoes, PSCs and Ozone Depletion

• Main Author: McCormick, M. Patrick
• Format: Text
• Language: unknown
• Published: Scholarly Commons 1995
• Subjects: Antarctic; The Antarctic; Antarc*
• Online Access: https://commons.erau.edu/space-congress-proceedings/proceedings-1995-32nd/april-27-1995/2; https://commons.erau.edu/context/space-congress-proceedings/article/1680/viewcontent/Volcanoes__PSCs_and_Ozone_Depletion.pdf

It is well known that human activity is perturbing the chemical composition and radiative balance of the Earth's atmosphere. Studies of the sensitivity of our climate to increasing concentrations of greenhouse gases, so named for their ability to retain heat in the atmosphere, predict that the increase of CO 2 concentration from a preindustrial value of -270 p.p.m. to 600 p.p.m. by the middle of the next century, along with expected increases in other greenhouse gases, will increase global surface temperature by 2-5°C This picture is complicated by the increasing concentrations of anthropogenic aerosols in the lower troposphere, which act to mitigate greenhouse warming. In the stratosphere, chlorine concentrations have increased because of anthropogenic chlorofluorocarbon production. Reactive chlorine compounds play an important role in the chemical processes that give rise to the Antarctic ozone hole, and the weight of evidence suggests that they also contribute to global losses of ozone, with possible concomitant increases in the intensity of biologically harmful ultraviolet-B radiation reaching the Earth's surface.