Viewing page 106 of 218
This transcription has been completed. Contact us with corrections.
THE CHANGING ATMOSPHERE-CHALLENGES AND OPPORTUNITIES 1.3 Impacts of Accelerating Climate Change There is widespread agreement among atmospheric scientists that over the next 50 years--easily within the lifetime of today's school-children--we will witness an accelerating change in climate of a magnitude greater than ever experienced since the beginning of human civilization. State-of-the-science climate models suggest that an average global warming of at least 3 [[degrees symbol]] F and perhaps 10 [[degrees symbol]] F is likely over the next 50 years. Although 3 [[degrees symbol]] F may seem small, it is larger than any sustained global warming experienced in the past 100,000 years. Furthermore, regional changes are likely to be much greater, perhaps several times as large. Should these changes occur, the impacts on our lives will be enormous. Potential impacts include: • A significant rise in sea level--on the order of several feet-- resulting in widespread shoreline erosion and inundation, especially during severe storms; loss of coastline, beaches, and wetlands and severe disruption of coastal industries; an increasing inland penetration of saline water, affecting drinking water and coastal ecosystems; and salinity intrusions in coastal freshwater aquifers. • A higher frequency and greater intensity of hurricanes. • Shifts in the geographic distribution of major agricultural areas and fisheries; for example, agricultural productivity may increase in Canada and the USSR and decrease in the United States. • Shifts in the paths of large-scale low-pressure weather systems, resulting in more precipitation in some regions and less in others, and a shift in the normal location if severe storms, including tornadoes. • Increases in the frequency and intensity of heat waves and droughts. • Further decreases in stratospheric ozone caused by the buildup of CFCs, with possible public health and agricultural effects. 1.4 Public Policy Implications Private and public institutions are now aware of these and other potential problems. National and international political responses are being considered, and in some cases, implemented, as in the Montreal Protocol. As another example, the Toronto Conference on the Changing Atmosphere in June 1988 brought together scientists and policy makers from 48 countries, who recommended a 20% reduction in carbon dioxide emissions by 2005 and a complete worldwide ban on the use of CFCs. 10
