Integrated interdisciplinary research, and the development of validated predictive models to enable us foresee likely impacts, are urgently needed. this enhanced research effort must be accompanied by precautionary measures to abate the process of climate change.

Effective preventive strategies to reduce the health hazards of climate change cannot be piecemeal. Policy responses must be made across many sectors, including industry, transportation, forestry, and agriculture.

Strategies must include industrial emissions control, energy conservation measures, land-use policies to maximize CO2 sinks, and population policies to minimize energy demand and destruction of natural CO2 sinks. Attempts to reduce greenhouse gas emissions are likely to fail if the world's natural CO2 sinks continue to be depleted by deforestation.

Policy decisions in relation to climate change will need to be taken on the basis of reasonable and prudent anticipation rather than demonstrable consequences. Precautionary measures aimed at reducing greenhouse warming will have many beneficial immediate effects on public health. For example, controlling air pollution and population growth would reduce stress --- in the form of acid precipitation and excessive demand --- on water resources.

Such short-term health gains weigh favorably in the policy debate, which must consider potentially irrevocable loner-term health consequences simultaneously with vast uncertainties.

Today's industrialized nations emerged economically at a time when environmental integrity and human health were not recognized as being linked to the sustainability of natural resources. But although the adverse consequences of environmentally insensitive economic growth are now understood, wealthy countries cannot expect poorer nations to unilaterally forego the short-term profits to be obtained from use of their natural resources.

Economically sustainable development will only be possible if environmentally sound technology is transferred from industrialized to developing countries. If less energy-intensive, affordable technologies are promoted and transferred to developing countries, pollutant emissions will be reduced and the global community as a whole will benefit. If not poorer nations will have no financial incentives to refrain from using cheap energy-inefficient technology or from harvesting their natural resources.

If adverse population health consequences are likely to result from climate change, we do not have the usual option of seeking definitive empirical evidence before acting. When the environmental health hazards arise from ecologically disruptive and potentially irreversible global environmental processes, such a "wait-and-see" approach would be imprudent at best and nonsensical at worst.