New Tahoe analysis adds 'when' and 'how much' to climate change forecasts

UC Davis News: UC Davis scientists today issued the most detailed forecast to date of likely climate-change effects at Lake Tahoe, complete with estimates of when those effects might be seen and how big they might be. Their findings suggest that even under the most optimistic projections:

• The average snowpack in the Tahoe Basin will decline by 40 to 60 percent by the year 2100;
• Floods will increase in the middle of the century;
• Prolonged droughts will become more common at the end of the century; and
• A new threat to the lake's unique ecology, one that will come from the very bottom of the lake, will become important by the second half of the century.

The report was written for the U.S. Forest Service's Pacific Southwest Research Station. Its lead authors are Robert Coats, a UC Davis researcher and consulting hydrologist, John Reuter, associate director of the UC Davis Tahoe Environmental Research Center, and Geoff Schladow, the center's director.

"Public dollars are funding restoration programs in the Tahoe region, which is a special place for millions of people," said Schladow. "For these programs to succeed, resource managers need to know what to expect in the coming decades.

"Will we have more or less snow, rain and runoff? Will the erosion controls and stormwater basins we are devising now still be useful in 30 or 50 years? What impact might climate change have for Lake Tahoe’s water quality and aquatic ecology?” Schladow said.

In recent years, UC Davis researchers have drawn on 100 years of data to describe changes in temperature and precipitation that have already occurred in the Tahoe region. The new report combines those findings with sophisticated computer models to produce detailed local projections out to the year 2100. The scientists considered two possible future carbon emission scenarios — one “business as usual” — in which population growth and national and international policies affecting global climate change remain unchanged — and the other “optimistic," assuming slower growth and aggressive climate action….

The vessel Tahoe Queen on Lake Tahoe, shot by Ville Miettinen, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license