THE climate of our planet is facing a threat of monumental proportions. Numerous scientists, including several from federal agencies, recently expressed this concern at a Senate hearing on environmental pollution. One of these scientists predicts that the continued use of the atmosphere as a dumping ground for byproducts of industrial activity will produce global temperatures in the next 15 years that exceed any in the previous 100,000. Others state that as early as the year 2030, unchecked emissions of carbon dioxide, methane, chlorofluorocarbons, and other gases will have caused a doubling of the heat-trapping capability of the natural atmosphere through a phenomenon known as the ``greenhouse effect.'' The consequences, which include a worldwide rise in temperature detectable as soon as 1990 and reaching up to 6 degrees F. by 2020, would be nothing short of disastrous for life as we know it. The environmental effects of global climate instability, which are similar to those of a nuclear war but far more certain, dwarf many of the environmental problems of the past.
The record-breaking temperatures, parched soils, and crop failures currently experienced in the South are a taste of the kind of change in weather patterns that can be expected. The difference will be that future climate alterations will be permanent, with no hope for relief from heat and drought. The Midwest could be 10 to 20 percent drier, with extreme heat waves and severe lack of precipitation reducing yields of corn, wheat, and other important food crops. Erosion in vulnerable areas on the East Coast would occur at the rate of 100 feet of beach for every foot of sea level rise, which could raise the level of the oceans 6 feet over the next 100 years. Scientists have predicted that the number of days in Washington, D.C., in which the temperature exceeds 100 degrees F. would jump from 1 to 12, and that on average the temperature would reach at least 90 degrees F. nearly 1 day out of every 4.
Carbon dioxide (CO2) from the burning of fossil fuels is the principal source of excess carbon dioxide in the atmosphere. Emissions are concentrated principally in industrialized parts of the world, although their effect is global. For instance, North America, home to only about 5 percent of the world's population, produces more than a quarter of all CO2 emissions. The world's forests are major ``sinks,'' or absorbers, of carbon dioxide. However, forest resources in tropical countries such as Brazil and Indonesia are being destroyed at the rate of more than 27 million acres annually.
Chlorofluorocarbons (CFCs), which are the most significant danger to the earth's protective stratospheric ozone shield that screens out ultraviolet radiation thought to be carcinogenic, are also major culprits contributing to climate modification. Emissions of these chemicals continue to increase despite the ban on their use in aerosol products in the United States. Recent data documenting an unexpected 50 percent decrease in ozone over Antarctica demonstrate that the ozone layer is still at risk. Because CFCs are produced by industry and are not found in nature, their emissions are controllable. The major reductions in production and use of CFCs necessary to safeguard stratospheric ozone will have additional benefits in eliminating climate modifications caused by these potent greenhouse gases, which cause at least one-sixth of the warming effect despite their relatively small concentrations in the atmosphere.
In the face of the most dire warnings from their own scientists, government bureaucrats have responded with a tired call for more research instead of action. This cavalier wait-and-see attitude mortgages the health and well-being of future generations. By the time temperature increases caused by the greenhouse effect become measurable, it may be too late.
A great deal can be done in the short term to avert the most devastating effects of business as usual. Major cuts in CFC emissions can be achieved in relatively short order. Energy efficiency and conservation programs containing strong incentives could reduce wasteful uses of fossil fuels, thereby cutting CO2 emissions. Government policies can encourage greater reliance on natural gas, which produces only about 60 percent as much carbon dioxide as coal for the same energy content. Efforts to conserve the world's forests can be intensified.
What can individuals do while governments drag their feet? Consumers can avoid CFC-containing products as much as possible. For example, one item still on the market relies on a CFC propellant to blast dust from photographic negatives and slides. The public can insist that all products containing CFC be labeled. Consumers can send a message to manufacturers that they want refrigerators and home and car air conditioners that do not threaten climate or ozone. Automobile air conditioning systems could be redesigned at modest cost to accommodate less harmful chemicals than those now in use. The public can demand appliances with dramatically reduced energy requirements designed to conserve energy. A typical frost-free refrigerator uses 1,200 kilowatt-hours per year; a state-of-the-art model, only 180.
Ultimately, however, the governments of the world will have to come up with a global strategy to deal with the greenhouse threat. To maintain a stable climate for the planet, all nations will have to be convinced that agreements to limit global emissions of ``greenhouse'' gases are both essential and in the best interests of all. Until then, the US public has a right to demand that government and industry in this country take rapid and effective measures to protect health and the environment from the catastrophic effects of climate disruption and ozone destruction.
David A. Wirth is senior project attorney at the Natural Resources Defense Council Inc., Wash.