The National Assessment of the Impacts of Climate Variability and Change

Report Looks at Likely Effects of Climate Change on United States Water Resources — and the News Isn’t Good

The National Assessment of the Impacts of Climate Variability and Change was a groundbreaking attempt to evaluate the impacts of climate change on the United States.

Led by the United States Global Change Research Information Office, the National Assessment drew on hundreds of top scientists with expertise in different areas to create a peer-reviewed compendium of the best information then available on climate change.

The Pacific Institute’s Dr. Peter Gleick was tapped to be lead author of the analysis for U.S. water resources, which was published by the Pacific Institute and the U.S. Geological Survey in December of 2000.

“Water: The Potential Impacts of Climate Variability and Change” finds that United States water resources are seriously threatened by climate change. Climate change, or global warming, as it is sometimes called, will lead to significant changes in the timing and location of rain and snow in the United States (and elsewhere). By upsetting the current patterns of precipitation, cities, states, and farming communities face serious threats to their water supplies. Regions dependent on snow-fed water supplies will be especially threatened as rising temperatures change snowfall and snowmelt dynamics.

Many other changes are likely, including effects on water quality, reservoir reliability, and storm frequency and intensity. The National Assessment water report describes these impacts, summarizes the levels of certainty and uncertainty involved, and offers recommendations for additional research and analysis.

The National Assessment water sector report is available from our website without charge and the full report is available from the Global Change Research Information Office.

More About the National Assessment

More than 40 new, peer-reviewed papers were produced during the production of the National Assessment, and nearly 1000 more were evaluated and summarized. The report went through extensive external reviews, including reviews by the different assessment teams, a diverse advisory group, two separate formal external scientific review periods, and a 60-day public comment period.

Despite this extremely rigorous process, the industry-funded Competitive Enterprise Institute (CEI) filed suit against the Federal government in an attempt to suppress the report. After an extended legal battle, the lawsuit was dropped “with prejudice”, meaning the courts told the CEI that it could not be refilled because the suit was entirely without merit.