Wednesday, October 19, 2011

Climate Change May Increase Great Lakes Water Levels

Oct 19: Previous studies of future climate change scenarios on the Great Lakes have pointed to falling water levels, but a new study by National Oceanic and Atmospheric Administration (NOAA) scientists at the Great Lakes Environmental Research Laboratory (GLERL) in Ann Arbor, gives a more optimistic outlook. Researchers have devised a new approach to modeling future water levels. Their work, now available online in the Journal of Great Lakes Research, predicts either a smaller drop or an actual rise in lake water levels under varying climate change scenarios. The impact of climate change on Great Lakes water levels is a critical question for the region's economy and environmental resources, as well as for one of the nation's key shipping corridors.

    Brent Lofgren, Ph.D., a GLERL scientist and lead author of the study said, "Even small drops in lake water levels create problems for shipping and navigation, hydroelectric energy production, and recreational boating. While there are still many unknowns about how climate change will unfold in the Great Lakes region, our results indicate less loss of water than earlier studies." The researchers used a different method than previous studies to account for how water evaporates into the atmosphere from the soil and plants in the drainage basin that surrounds the lakes, i.e. evapotranspiration. Earlier studies used air temperature alone to estimate this variable. The new GLERL study uses an "energy budget-based approach" to better reflect the balance between energy coming in from the sun and energy given off from the Earth, which drives evaporation.

    Access a release from NOAA and link to information on obtaining the article online (click here).