ABSTRACT
Science provides abundant reasons policy makers and the public ought to be concerned about climate change (e.g. Watson et al. 1996; OTA 1993; NAS 1992). Although some outcomes of climate change are thought to be potentially positive, such as carbon fertilization of plants or ice-free Baltic ports, public and scientific attention are mostly focused on the potential negative impacts of temperature and precipitation changes on human populations and the ecological systems on which humans depend. Examples of the former include direct impacts such as more floods and increased energy demand for heating and cooling, as well as indirect impacts such as changes in nutrition due to agricultural shortages and new patterns of vector-borne diseases. Ecological impacts could result from changes in the duration and timing of growing seasons, the availability of fresh water supplies, and sea-level rise. 1
