Environmental Health Center

Potential Impacts of Climate Change and El Niño in the Mississippi Basin Potential Impacts of Climate Change in Alaska Potential Impacts of Climate Change in California Potential Impacts of Climate Change in the Southwest Potential Impacts of Climate Change in the Pacific Northwest Potential Impacts of La Niña on Climate Variability and Extreme Weather

Floods, drought, tornadoes, hurricanes, and other wild weather fill the newspapers and newscasts almost daily. We seldom think about these things (and the media seldom cover them) until they threaten disaster.

These extreme weather events are the ones that cause the most devastation and disruption in human lives. A certain amount of extreme weather is "normal." Weather and climate scientists understand much more about what causes these extremes today than they did a decade ago. One result is new skill in forecasting weather extremes, skill that can save lives and property.

As understanding of the El Niņo cycle and other longer-term patterns of climate variability improves, fewer extreme weather events need to be explained as random freaks of nature. But there is still plenty of uncharted territory, too. The world seems likely to experience significant warming in coming centuries as a result of manmade greenhouse gases. How this will play out in any particular region is less clear. Not only may the weather pendulum swing farther past the warm end of its range, but climate change could also bring more variability - wilder, less regular, or more frequent swings of the pendulum.

While precise certainties about climate variability and change in a particular region may be hard to come by, we already know much about how extremes of weather affect different regions and how they are vulnerable.

This series of backgrounders is meant to examine, region by region, what those impacts and vulnerabilities might be. The Environmental Health Center is producing this series under a grant (#0096-0032) from the National Oceanic and Atmospheric Administration. Paper copies are available by writing: Weather Backgrounder, EHC, Suite 1200, 1025 Connecticut Ave., NW, Washington, DC 20036.

While one of the main purposes of the series is to provide useful background for journalists, EHC and NOAA also hope it will be useful for members of the general public.