Environmental issues that may become priorities in the 21st century can be clustered in three groups - unforeseen events and scientific discoveries; sudden, unexpected transformations of old issues; and already well-known issues to which the present response is inadequate. The Scientific Committee on Problems of the Environment of the International Council for Science conducted a special survey for GEO-2000 on environmental issues that may require attention in the 21st century. Most of the responding scientists expect that the major environmental problems of the next century will stem from the continuation and aggravation of existing problems that currently do not receive enough policy attention. The issues cited most frequently are climate change, and the quantity and quality of water resources. Many scientists emphasized that the interlinkages between climate change and other environmental problems could be important. This includes the emerging scientific understanding of complex interactions in the atmosphere-biosphere-cryosphere-ocean system - which could lead to irreversible changes such as shifts in ocean currents and changes in biodiversity.
There are three ways of making predictions about the future climatic conditions: theory, computer models and existing data. All existing theoretical models about the climate are crude and very limited, as illustrated by the accuracy of weather forecasts of periods longer than five days. Computer models of the climate are based on theory and are limited. The use of existing data, that is past data, is a poor guide to the future.
The Encyclopedia of World Problems and Human Potential is a collaboration between UIA and Mankind 2000, started in 1972. It is the result of an ambitious effort to collect and present information on the problems with which humanity is confronted, as well as the challenges such problems pose to concept formation, values and development strategies. Problems included are those identified in international periodicals but especially in the documents of some 60,000 international non-profit organizations, profiled in the Yearbook of International Organizations.
The Encyclopedia includes problems which such groups choose to perceive and act upon, whether or not their existence is denied by others claiming greater expertise. Indeed such claims and counter-claims figure in many of the problem descriptions in order to reflect the often paralyzing dynamics of international debate. In the light of the interdependence demonstrated among world problems in every sector, emphasis is placed on the need for approaches which are sufficiently complex to encompass the factions, conflicts and rival worldviews that undermine collective initiative towards a promising future.
Non-profit, apolitical, independent, and non-governmental in nature, the UIA has been a pioneer in the research, monitoring and provision of information on international organizations, international associations and their global challenges since 1907.