Knowra Ozone depletion Ozone depletion Ozone depletion is the reduction of ozone concentration in Earth’s stratosphere, driven especially by catalytic reactions involving chlorine and bromine released from human-produced compounds.
Chlorofluorocarbon : A synthetic compound containing carbon, chlorine, and fluorine, formerly widely used in refrigeration, aerosols, and foam production. Stratospheric ultraviolet light breaks these compounds apart, releasing chlorine that catalytically destroys ozone.
Mario Molina : A Mexican-American chemist who helped establish how chlorofluorocarbons could deplete stratospheric ozone. His work with F. Sherwood Rowland predicted that CFCs would release ozone-destroying chlorine.
Montreal Protocol : A 1987 international treaty that controls production and consumption of ozone-depleting substances. It coordinated the phaseout of major chemicals responsible for human-caused ozone depletion.
Ultraviolet-B : The ultraviolet wavelength band from about 280 to 315 nanometers, partly absorbed by stratospheric ozone. Thinning ozone allows more UV-B radiation to reach Earth’s surface.
Tropospheric ozone : Ozone present in the lowest atmospheric layer, where it acts as an air pollutant and greenhouse gas. Unlike stratospheric ozone loss, rising ground-level ozone is usually caused by pollution chemistry.
Bromine : A chemical element whose reactive compounds participate in ozone-destroying cycles in the stratosphere. Bromine atoms destroy ozone especially efficiently and amplify the effects of chlorine.
F. Sherwood Rowland : An American chemist whose research with Mario Molina linked chlorofluorocarbons to stratospheric ozone loss. Their 1974 analysis identified a global atmospheric consequence of otherwise stable industrial chemicals.
Dobson spectrophotometer : An instrument that measures total-column atmospheric ozone by comparing ultraviolet wavelengths absorbed by ozone. Long-running ground observations helped identify and track ozone losses.
Skin cancer : A group of cancers arising from skin cells, with ultraviolet radiation among their established risk factors. Increased UV-B exposure raises risks of some skin cancers.
Ozone pollution : Harmful near-surface ozone formed when nitrogen oxides and volatile organic compounds react in sunlight. It is an air-quality problem, not the same phenomenon as stratospheric ozone depletion.
Show all 26