Freshwater ecosystems, hydrology and water resources
Magnuson reviewed some of the controversies that arose during the development of the water-related chapters of the 1995 IPCC WG II report as well as some of the major findings of the chapters related to fresh water. To begin, he points out that fresh water is a critical human resource and essential to the functioning of all natural ecosystems, and that freshwater systems are among the most sensitive responders to climate change (McKnight, Naiman). Controversies in the IPCC chapter on fresh water ecology began early with the question of whether such a chapter should be included in the assessment at all. Prior to a rather late review of draft chapters, it was thought that the information would come through in chapters on hydrology, oceans and large lakes, non-tidal wetlands, and water supply; but it did not. The subject of fresh water ecology sometimes falls into the cracks between oceanography and terrestrial ecology. A second controversy had to do with water supply versus water quality issues. A third controversy arose because some authors, particularly in the water supply chapter, felt that the climate scenarios were so uncertain that perhaps they should not even be used. In the end, Magnuson said he believed that issues dominated over personalities, and the 1995 IPCC Working Group II report usefully incorporated freshwater quality and ecology into a chapter on Hydrology and Freshwater Ecology. The review system was responsive and flexible in making a place for this information late in the writing and review process. The system could have failed but did not. Magnuson said that those involved learned that the lead authors should take a broad perspective and be inclusive rather than exclusive in the materials considered, that the limited number of pages allocated to a chapter not be used as a way to exclude points of view or significant new information, and that advocacy for a particular outcome must be recognized and dealt with.
Global Change Institute