The freshwater ecosystems in the mid-Atlantic region of the United States are already undergoing stress.  This area has a history of changing land use and a growing human population. 

Human activity combined with the additional stress of climate change are expected to significantly impact freshwater ecosystems.  Recent computer model simulations have suggested that, by the year 2100, temperatures in Virginia could increase by 3oF in winter, spring and summer (range of 1-6o F) and 4oF in the fall (with a range of 2-8oF).  Precipitation is expected to increase by 20% in all seasons.  (EPA report, Climate Change in Virginia.  September 1998.  EPA 236-F-98-007bb).

Global warming won’t affect the way the water cycle works, but it can significantly affect parts of the water cycle, leading to either droughts or floods.  Both events will impact aquatic ecosystems.

Animation of global temperature anomalies from 1880 to 2006 taken as a five-year moving average. Dark blue indicates areas cooler than average. Dark red indicates areas warmer than average. This animation is annotated with the year that ends the five-year time span used in calculating the moving average.

Animation provided by NASA/Goddard Space Flight Center Scientific Visualization Studio Data provided by Robert B. Schmunk (NASA/GSFC GISS)