Specific Connection in Energy-Water Nexus

The effects of climate change include:

• Increased lower atmospheric temperatures
• Increased variability of the water cycle
• Decreased snowpack
• Earlier snowmelt
• Increased potential for flood and drought

Mountain snowpack acts as a water reservoir during winter months. When the volume of snowpack declines and snowmelt occurs early, surface water availability is reduced for all users (agriculture, urban, industry, energy production), and other water sources must be utilized. More frequent occurrences of droughts or flood events also decrease the availability of surface water. Augmenting the surface water shortfall with groundwater is only a short-term solution. As groundwater is withdrawn and recharge decreases, the water table declines. As groundwater supplies become deeper and more difficult to obtain, pumping and associated electricity costs increase.

Resource Quantities

Global climate change directly affects both the energy and water sectors. Changes in climate have forced cities and regions to choose between energy production and water distribution, as the following examples illustrate.

• During California’s energy crisis in the summer of 2001, the state faced the risk of even larger, more frequent blackouts because a severe drought in the Pacific Northwest had drained hydroelectric power resources (Washington Post, Feb. 1, 2001).
• Low municipal water supplies have led many localities to issue voluntary or mandatory water restrictions. For example, in 2003 the Colorado River, which depends on snowpack run-off, flowed at 25 percent of its historic average, the Salt River at one-sixth its average (Electric Perspectives, July/August 2003).
• Recent analyses of climate projections and hydrologic response in California indicate that by 2100 snow amounts in the Sierra Nevada may be only 20 to 40 percent of present levels (Miller et al., 2003; Hayhoe et al., 2004).

Sector Challenges and WETT Solutions

Scientists on the Water and Energy Technology Team (WETT) at Lawrence Berkeley National Laboratory (LBNL) have been contributing fundamental research to the U.S. Intergovernmental Panel on Climate Change Assessment Reports, including the U.S. National, Southwestern United States, and California assessments. LBNL led the early development of a Regional Climate System Model for understanding climatic components at scaling factors that range from local to regional. WETT researchers investigate past, present, and future climates at regional and subregional scales and at various temporal resolutions. This research utilizes historical analysis of global climates, weather forecasts, seasonal forecasts, and long-term projections of carbon dioxide conditions.

For additional information, visit the Hydroclimate and Impacts Research Site, http://esd.lbl.gov/RCC/