Recycling on National Parks. Now in its third year, a program cosponsored by the National Park Service, Dow Chemical, and Huntsman Chemical is among the first and largest recreation recycling efforts. To date, 600,000 pounds of material in six national parks have been recycled through the program. In 1992 the National Mall in Washington, D.C., became the seventh participating national park. The 160 bins to be set up on the Mall will collect hundreds of tons of material per year. Dow and Huntsman are underwriting program costs, including the design and installation of recycling bins, collection of recyclables, informational exhibits, and technical support. Start-up costs for the Mall project are $250,000 for trucks and daily collection. In 1992 alone, Dow and Huntsman spent $500,000 on establishing new recycling in the seven national parks that together attract 23 million visitors each year. Paper and Wood Recycling. The Forest Products and Harvesting Research Program of the USDA Forest Service has embarked on a national recycling effort to reduce by half the paper and wood in the municipal waste stream. Only 25 percent of the wood and paper discarded annually is recycled, while waste paper accounts for 40 percent of the volume in landfills. Scientists are seeking new technologies to make more efficient use of recovered paper, paperboard, and wood waste. They are working to improve the quality of recyclable material from paper and to develop alternative, nonpaper products from recycled wood fiber. They also are evaluating the economics of technologies for using recycled wood fiber and the economic and environmental impacts of expanded recycling. Waste to Energy. In 1990, of all U.S. municipal solid wastes, 16 percent were combusted. Currently, 150 municipal waste-to-energy plants are in operation, combusting waste and converting 15 percent of the nation's solid waste into energy. In February 1991 EPA issued regulations for waste-to-energy plants, controlling air emissions of organics, heavy metals, and acid gases such as hydrochloric acid. Regulations ensure the maintenance of proper combustion conditions. Although combustion products-residue or ash-may be high in concentrations of heavy metals, they can be safely handled in landfills that meet the new national standards. The National Energy Strategy projects that waste-to-energy plants in the year 2010 will produce seven times the amount of power that they currently generate. Landfills. In 1991 EPA issued regulations to improve the safety of municipal solid waste landfills to become effective in October 1993. New management standards cover the following categories of concern: location restrictions, operating requirements, design standards, groundwater monitoring and corrective action, closure and post-closure care, and owner/operator financial responsibility. Regulations cover facilities throughout their operating life and during their post-closure care period for 30 years. The rule may create an incentive for increasing source reduction and recycling nationwide because of the increased costs of disposal. International Issues Also see Biodiversity, Coasts and Oceans, Economics, Fisheries and Marine Mammals, Forestry, and related tables and figures in Part II. n 1992 the United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro in June, made front-page news of the linkages between environmental quality and economic development. Sustainable Sustainable development -defined as managing the Earth's resources in a way that ensures their long-term quality and abundancebecame the goal toward which nations committed themselves at home and at the "Earth Summit." Conditions and Trends During the past year, policymakers and the general public received a stream of scientific reports on the global nature of many environmental problems. Among the transboundary issues of greatest concern were biodiversity, forests, global climate change, oceans, and ozone-layer depletion. Biodiversity The biological wealth that scientists call biodiversity encompasses the Earth's variety of distinct species, the genetic variability within them, and the variety of ecosystems they inhabit. At the present time, no one has full and accurate information on the status and distribution of biodiversity components or on the functioning of ecosystems, but current evidence offers reason for concern. Leading authority E.O. Wilson of Harvard University estimates that the current worldwide rate of extinctions exceeds 1,000 times the natural rate. Each of these losses from the world's natural heritage represents the potential loss of ecological, economic, and aesthetic benefits. The loss of biodiversity can result from a number of factors, particularly habitat loss and fragmentation, over-exploitation of species, introduction of intrusive species into an ecosystem, pollution, climate change, and industrial agriculture and forestry. These factors are not confined to tropical regions but affect temperate ecosystems as well. For a discussion of conservation efforts, see the Biodiversity section. Forests Forests that provide services and products of ecological and economic value locally, nationally, regionally, and globally are under stress around the world. According to the 1990 assessment of the U.N. Food and Agriculture Organization, tropical forests are disappearing at a rate of 17 million hectares (42 million acres) per year. Responding to population pressures and poverty, many nations provide subsidies and incentives for forest conversion to farmland and pasture. Other causes include destructive logging practices; overharvest of commercial forests; subsidized timber sales; large-scale development projects; and lack of clearly defined property rights, leading to the "tragedy of the commons" problem. Temperate and boreal forests, although expanding in some areas, are substantially degraded in others primarily because of air pollution, inefficient harvesting, and lack of reforestation. In some parts of Eastern Europe, forest dieback caused by air pollution is as high as 50 percent. For a discussion of conservation efforts, see the Forestry section. Global Climate Change Certain atmospheric gases—including carbon dioxide, methane, and nitrous oxide-trap solar rays that would otherwise be radiated back into space. Without this "greenhouse effect," Earth would be uninhabitably cold. But many scientists believe rising emissions of greenhouse gases from human activity could lead to "global warming" and negative changes in sea level, frequency and intensity of storms, precipitation patterns, and incidence of droughts. Greenhouse gases are emitted by various sources and stored in biological or chemical "sinks." Sources and sinks include the burning of fossil fuels such as coal and oil, industrial processes, changes in forest cover and land use, certain agricultural practices, and biodegradation of wastes. Greenhouse gas emissions occur in all nations; for example, the National Academy of Sciences estimated in 1983 that about 25 percent of worldwide carbon dioxide emissions from fossil fuel combustion arises in the United States, 25 percent in Western Europe and Japan, 25 percent from the former Soviet Union and Eastern bloc, and 25 percent from developing nations. Industrialized country shares are declining relative to those of developing countries. The Intergovernmental Panel on Climate Change (IPCC), created under the auspices of the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP), issued its first assessment in 1990 on the science, impacts, and possible responses to climate change. The report projected a global average temperature rise of 0.2 to 0.5 degrees Centigrade per decade through the next century, if no actions are taken to limit net greenhouse gas emissions. Global temperature increases at that rate would be greater than any experienced in human history. However, the IPCC report also noted uncertainties that hamper scientists in making accurate predictions about the timing, magnitude, and regional distribution of climate change. Key unknowns include the way carbon Chlorofluorocarbons (CFCs) and sulfate aerosols may offset greenhouse warming. •Current assumptions used to compare the global warming potential of greenhouse gases may be inaccurate. Oceans The productive and regenerative capacities of the world's oceans are also threatened by pollution and over-utilization. Coastal regions, as sites with concentrated natural resources and human development, are particularly at risk. Habitats are being lost irretrievably to the construction of harbors and industrial installations, the development of tourist facilities and mariculture, and the growth of settlements and cities. Although difficult to quantify, destruction of beaches, coral reefs, and wetlands, as well as increased erosion of the shore, are evident all over the world. In contrast to the coasts, the open sea remains relatively clean, although trends for certain species are of concern. Lead, synthetic organic compounds, and artificial radionuclides are widely detectable at very low levels. Small oil slicks and litter common along sea lanes are unsightly but, for the most part, of minor consequence to communities of organisms living in open-ocean areas. For discussions of efforts to conserve the world's ocean resources, see the Coasts and Oceans section and the Fisheries and Marine Mammals section. Ozone-Layer Depletion Significant findings emerged over the last year on the condition of the stratospheric ozone layer, which protects the Earth's surface from harmful levels of solar radiation. Early in the year, UNEP released its latest International Ozone Assessment, and findings were issued from the second U.S. Air borne Arctic Stratospheric Expedition. Both studies presented evidence that ozone depletion may occur more rapidly and widely than previously suspected, leading to concerns about potential increases in incidence of skin cancer, cataracts, and ecological damage. In the fall, the U.S. government announced additional troubling news: the widest ever ozone depletion over Antarctica. Concern also emerged over a substance previously not recognized as an ozone-depleting chemical. The 1992 UNEP assessment identified methyl bromide as potentially having a high ability to deplete stratospheric ozone, although it noted a need for additional, intensive research. For many agricultural uses of methyl bromide, safe alternatives have yet to be identified. Policies and Programs In 1992 worldwide progress in protecting the ozone layer, endangered species, and regional air and water quality continued under various international agreements and U.S. initiatives. Most significantly, two years of preparations for the United Nations Conference on Environment and Development (UNCED) culminated in adoption of new international policies, embodied in The Rio Declaration, Agenda 21, and A Statement of Forest Principles. At UNCED, newly negotiated conventions on climate change and biodiversity were opened for signature. The following update on major international environmental issues is presented in alphabetical order. Antarctica. In October 1991 the United States and most other Antarctic Treaty Parties signed a protocol on environmental protection in Antarctica with provisions on the conservation of |