The most significant event in the environmental arena in 1996 was the release of a report by the Intergovernmental Panel on Climate Change (IPCC) stating that "the balance of evidence suggests a discernible human influence on global climate" (IPCC Second Assessment Report, Summary for Policymakers: The Science of Climate Change, IPCC Working Group I, 12/95). The IPCC report, adopted in Rome in 1995, represents the consensus of over 2,000 scientists from around the world. The group was first assembled by the UN Environment Program (UNEP) and the World Meteorological Organization (WMO) in 1988, prior to the negotiations on the climate change treaty, to provide objective assessments of scientific research on climate change.
The first IPCC report, issued in 1990, was not able to identify with certainty a human-induced effect on climate distinct from natural climate variability. Considerable scientific process has been made since 1990, however, as new data and analyses have become available. Despite pressures from some oil-producing states and fossil fuel-related companies to emphasize continuing uncertainties, the 1995 IPCC report concluded that "the observed warming trend is unlikely to be entirely natural in origin" (ibid., p. 41). Atmospheric concentrations of greenhouse gases, including carbon dioxide, methane, and nitrous oxide, have grown significantly as a result of human activities, according to the report, mostly due to fossil fuel combustion, land-use changes, and agricultural practices (ibid., p. 1). Since carbon dioxide and nitrous oxide can remain in the atmosphere for long periods of time, even centuries, their concentrations would continue to increase even if emissions remained at present levels.
The IPCC's "best estimate" is that global mean surface air temperatures will show an increase of two degrees from 1990 to 2100. The projected range is one degree to three and a half degrees, reflecting differing assumptions about future population and economic growth, land use, technology, energy availability and fuels. The average sea level is expected to rise about fifty centimeters during the same period, due to melting glaciers and ice sheets, and to continue to rise in future centuries (ibid., p. 5).
The projected changes sound small, but the impact could be catastrophic. Even slightly higher average temperatures could result in a variety of regional effects: a greater number of extremely hot days and severe droughts in some areas, and heavier rainfall and flooding in others (ibid., p.6). With about half the world's population living along coastlines, a small rise in sea level would present a serious threat to large numbers of communities-especially in conjunction with more intense rainfall or serious storms. The report also warns that "sustained rapid climate change could shift the competitive balance among species and even lead to forest die-back, altering the terrestrial uptake and release of carbon" (ibid., p. 7).
While the report is far from cheerful, the very existence of the IPCC highlights the essential role of the United Nations in identifying and investigating critical environmental issues requiring international attention. More important, the United Nations has established the legal framework for addressing many of these issues through international treaties on climate change, biological diversity, and desertification as well as through treaties to protect the oceans and the ozone layer.
From A Global Agenda: Issues Before the 51st General Assembly of the United Nations, (excerpt from Global Resource Management, by Gail V. Karlsson). Copyright 1996 by the United Nations Association of the United States of America. Published by University Press of America, Inc.
