Modeling Climate Change Impacts
To evaluate the impacts of continued climate change on the Lake Tahoe thermal properties, water level, internal nutrient loading, nutrient cycling, aquatic ecosystem, and other important features of lake limnology we used statistically downscaled outputs (2001-2100) of the Geophysical Fluid Dynamics Laboratory Model (GFDL) for two different green house gas emission scenarios A2 and B1 . The outputs of the hydrology model together with downscaled climate data drive the DLM-WQ model for the lake.
The results indicated that, with the higher emission scenario (A2), the lake will continue to warm, and become more thermally stable. Deep mixing will cease for long periods and the deep water of the lake will become anoxic, triggering a large release of available phosphorus and nitrogen, and a significant loss of well oxygenated lake volume that now serves as salmonid habitat. By the end of the century, the lake water level may drop below the natural rim. This infers that strict application of water quality Best Management Practices offers an opportunity to mitigate the potentially disastrous impacts of climate change.
The Tahoe Climate Change Project was supported by grant #08-DG-11272170-101 from the USDA Forest Service Pacific Southwest Research Station using funds provided by the Bureau of Land Management through the sale of public lands as authorized by the Southern Nevada Public Land Management Act.