Higher summer temperatures will increase electricity use, causing higher summer peak loads, while warmer winters will decrease energy demands for heating. Net electricity use is projected to increase.

This finding is from chapter 4 of Climate Change Impacts in the United States: The Third National Climate Assessment.

Process for developing key messages: The author team met bi-weekly by teleconference during the months of March through July 2012. Early in the development of key messages and a chapter outline, the authors reviewed all of the four dozen relevant technical input reports that were received in response to the Federal Register solicitation for public input. Selected authors participated in a U.S. Department of Energy (DOE) sponsored workshop on Energy Supply and Use, December 29-30, 2011 in Washington, D.C. The workshop was organized specifically to inform a DOE technical input report and this National Climate Assessment and to engage stakeholders in this process. The authors selected key messages based on the risk and likelihood of impacts, associated consequences, and available evidence. Relevance to decision support within the energy sector was also an important criterion. The U.S. maintains extensive data on energy supply and use. The Energy Information Administration (EIA) of the U.S. Department of Energy is a primary organization in this activity, and data with quality control, quality assurance, and expert review are available through EIA Web pages (for example, EIA 2012, EIA 20132af3709d-81eb-48b7-9183-afc6c27015ea 9f0adb9b-5a9c-4fc2-8df7-ebed4322e185).

Description of evidence base: Climate scenarios prepared for the NCA0ebef171-4903-4aa6-b436-2936da69f84e describe decreases in precipitation under the SRES A2 scenario, with the largest decreases across the Northwest and Southwest in the spring and summer. Technical input reports (for example, Wilbanks et al.f0803451-5a89-474a-974f-99c13fdc725d 3c34748e-be5d-4831-896e-70cbae0f0d22) summarize data and studies show that changes in water availability will affect energy production,552cc5f5-a7b3-4a64-8bee-98ae0cced150 and more specifically, that water shortages will constrain electricity production (Ch. 2: Our Changing Climate).843cf523-c36c-4e7d-8824-22f65394aad9 d0828222-3fd7-4527-8d2a-895581c96ca3 2c825d36-342b-4b91-a851-bcefdb5d42da The impacts of drought in Texas during 2011 are an example of the consequences of water shortages for energy production as well as other uses (Ch. 10: Energy, Water, and Land). Electric utility industry reports document potential consequences for operation of generating facilities.2e002d5f-fcf1-4d2e-a8b9-7f672a26e5a1 A number of power plants across the country have experienced interruptions due to water shortages.

New information and remaining uncertainties: An increasing number of documented incidents of interruptions in energy production due to water shortages provide strong evidence that decreased precipitation or drought will have consequences for energy production.3c34748e-be5d-4831-896e-70cbae0f0d22 There is little uncertainty that water shortages due to climate change will affect energy production. But uncertainty about changes in precipitation and moisture regimes simulated by global climate models is significantly higher than for simulated warming. Additionally, climate change simulations lack the spatial and temporal detail required to analyze the consequences for water availability at finer scales (for example, local and regional). Finer-scale projections would be relevant to decisions about changes in energy facilities to reduce risk or adapt to water shortages associated with climate change.

Assessment of confidence based on evidence: High. The evidence is compelling that insufficient water availability with climate change will affect energy production; however, simulations of climate change lack the detail needed to provide more specific information for decision support.

References :

• Annual Energy Outlook 2012 with Projections to 2035. DOE/EIA-0383(2012) (2af3709d)
• Monthly Energy Review (9f0adb9b)
• Climate Change and Energy Supply and Use. Technical Report to the U.S. Department of Energy in Support of the National Climate Assessment (3c34748e)
• Regional Climate Trends and Scenarios for the U.S. National Climate Assessment: Part 9. Climate of the Contiguous United States. NOAA Technical Report NESDIS 142-9 (0ebef171)
• Climate Change and Infrastructure, Urban Systems, and Vulnerabilities. Technical Report to the U.S. Department of Energy in Support of the National Climate Assessment (f0803451)
• Climate and Energy-Water-Land System Interactions. Technical Report to the U.S. Department of Energy in Support of the National Climate Assessment. PNNL-21185 (552cc5f5)
• Water use for electricity in the United States: an analysis of reported and calculated water use information for 2008 (843cf523)
• The water implications of generating electricity: water use across the United States based on different electricity pathways through 2050 (d0828222)
• Characterizing changes in drought risk for the United States from climate change (2c825d36)
• Water Use for Electricity Generation and Other Sectors: Recent Changes (1985-2005) and Future Projections (2005-2030). 2011 Technical Report (2e002d5f)