Climate Variability and Change
This page is designed to help Colorado River Basin water managers locate existing climate change science information including international and national assessments as well as information and resources specific to the basin. Visit the other Colorado River Resources pages for additional information pertaining to the Colorado River Basin.
International & National Assessments
Intergovernmental Panel on Climate Change (IPCC)
WWA's Guide to the IPCC
2007 WGI Fourth Assessment Report Summary for Policy Makers
2001 Third Assessment Reports including Working Group I, Working Group II, Working Group III, and the Synthesis Report
Recognizing the problem of potential global climate change, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) established the Intergovernmental Panel on Climate Change (IPCC) in 1988. The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation. On this site you can find links to all the publications and summaries for policy makers.
At its first session, the IPCC was organized into three Working Groups. The current remits of the Working Groups are for Working Group I to address the scientific aspects of the climate system and climate change, Working Group II to address the impacts of and adaptations to climate change, and Working Group III to address the options for the mitigation of climate change. In addition, a Synthesis Report is included in the links below and is a summary of reports from all three working groups. The IPCC provided its first major assessment report in 1990 and its second major assessment report in 1996. The Third Assessment Report, (TAR) was released in 2001 and the Fourth Assessment, Working Group I Report was released in February 2007.
Presentation overview of the state of climate change science by one of the IPCC lead authors, Dan Albritton.
(NAS) National Academic Press: An Analysis of some key questions about climate science, National Academy Press, 2001
This study originated from a White House request to help inform the Administration’s ongoing review of U.S. climate change policy. In particular, the written request asked for the National Academies’ “assistance in identifying the areas in the science of climate change where there are the greatest certainties and uncertainties,” and “views on whether there are any substantive differences between the Intergovernmental Panel on Climate Change (IPCC) Reports and the IPCC summaries.” The White House asked for a response less than one month after submitting its formal request.
For the task of comparing IPCC Reports and Summaries, the committee focused its review on the work of IPCC Working Group I. The committee decided to address the questions in the context of a brief document that also could serve as a primer for policy makers on climate change science. The report does not make policy recommendations regarding what to do about the potential of global warming. Thus, it does not estimate the potential economic and environmental costs, benefits, and uncertainties regarding various policy responses and future human behaviors.
Climate Change Impacts on the United States: The Potential Consequences of Climate Variability and Change, 2003
National Assessment Synthesis Team, US Climate Change Science Program: (www.climatescience.gov), US Global Change Research Program: (www.usgcrp.gov)
Relevant Chapters:
Chapter 8: Potential Consequences of Climate Variability & Change for the Western United States
Chapter 7: Potential Consequences of Climate Variability & Change for the Great Plains
Chapter 14: Potential Consequences of Climate Variability & Change for the Water Resources of the United States
Water Sector research
Western Region research
A group of studies starting in 1999 on the impacts of climate change and variability on different sectors and regions of the U.S. They are designed to mimic the IPCC studies, but focus on the United States. The National Assessment of the Potential Consequences of Climate Variability and Change is a landmark in the major ongoing effort to understand what climate change means for the US. Climate science is developing rapidly and scientists are increasingly able to project some changes at the regional scale, identifying regional vulnerabilities, and assessing potential regional impacts. Science increasingly indicates that the Earth's climate has changed in the past and continues to change, and that even greater climate change is very likely in the 21st century. This Assessment has begun a national process of research, analysis, and dialogue about the coming changes in climate, their impacts, and what Americans can do to adapt to an uncertain and continuously changing climate. This Assessment is built on a solid foundation of science conducted as part of the United States Global Change Research Program (USGCRP).
US Climate Change Science Program (CCSP) Synthesis & Assessment Products (SAPS)
In response to the National Academy of Sciences Report, President Bush launched the Climate Change Research Initiative (CCRI) in June 2001 to further investigate the climate effects of green house gases, the global carbon cycle, and climate modeling and observations to support decision-making on a national scale. From there, the President called for improved government-wide management of climate science and launched two collaborative interagency programs: the Climate Change Science Program (CCSP) and Climate Change Technology Program (CCTP) in February 2002.
Climate Change and U.S. Water Resources. (1990)
An edited book by Paul Waggoner. An overview in 19 chapters on what climate change will mean for water resources. Despite the date, still very relevant.
Climate Variability and Change in the Colorado River Basin (and the West)
Academic Studies & Resources
Please visit our other Colorado Resource pages including Regional Hydrology and Geography and Drought Impacts and Management
In Hot Water: Water Management Strategies to Weather the Effects of Global Warming
Natural Resource Defense Council, July 2007
Colorado River Streamflow: A Paleo Perspective Webpages
Model projections of an imminent transition to a more arid climate in southwestern North America
Richard Seager, Mingfang Ting, Isaac Held, Yochanan Kushnir, Jian Lu, Gabriel Vecchi, Huei-Ping Huang, Nili Harnik, Ants Leetmaa, Ngar-Cheung Lau, Cuihua Li, Jennifer Velez, and Naomi Naik Published online April 9 2007; 10.1126/science.1139601 (Science Express Reports)
Executive Summary, Colorado River Basin Water Management: Evaluating and Adjusting to Hydroclimatic Variability, The National Academies Press, February 2007
Full Report Available for sale through the National Academies Press
Past Peak Water in the West, Martin Hoerling (NOAA) and Jon Eischeid (CIRES), Southwest Hydrology, January/February 2007
Climate and Tourism Workshop. Tourism and recreation in the West are a large part of the economy and are strongly linked to climate. This workshop will result in an applied research and services agenda. This workshop is sponsored by WWA and The Center for Sustainable Tourism, Leeds School of Business, University of Colorado. National Center for Atmospheric Research (NCAR), January 23-24, 2007. Researchers Pulwarty, Kenney, Alvord, Udall.
Climate Change and its implications for the Rocky Mountain region
Smith, J., Wagner, C.
Journal of American Water Works Association, 98:6, June 2006
This article briefly reviews what is known about climate change in a general sense and what projected impacts are for he Colorado Rockies, Front Range, and western Great Plains.
Climate Change and Water Resources: A Primer for Municipal Water Managers. (2005)
A report by Kathleen Miller and David Yates, funded by the University Corporation for Atmospheric Research (UCAR) and the American Water Works Association Research Foundation.
Jacobs, K., and Pulwarty, R., 2004: Climate, science and decision making.
In Lawford, R., et al (eds): Water: Science, Policy and Management. AGU Monograph. AGU Press Washington DC 177-204
Pulwarty, R., 2003: Climate and water in the West: Science, information and decision making.
Water Resources (Update) 124, 4-12
Effects of Climate Change on the Hydrology and Water Resources of the Colorado River Basin. (2004). Niklas S. Christensen, Andrew W. Wood, Nathalie Voisin, et al. Climatic Change, vol 62, pp. 337 - 363.
The most recent of the very few articles on the potential effects of climate change on the hydrology of the Colorado River.
Ongoing research by Niklas Christensen of the University of Washington's Land Surface Hydrology Group, Department of Civil and Environmental Engineering.
Effects of temperature and precipitation variability on snowpack trends in the western U.S.
Hamlet, A. F., P. W. Mote, M. Clark, and D. P. Lettenmaier. To appear in Journal of Climate.
Declining mountain snowpack in western North America. (2005). Mote, P. W., A. F. Hamlet, M. Clark, and D. P. Lettenmaier. Bulletin of the American Meteorological Society 86(1):39-49.
Cover story of the Jaunary 2005 edition of the Bulletin of the American Meteorological Society. This research shows that while there has been a decline in snowpack in the Pacific Northwest, there is not a similar signal in the Colorado River Basin.
The Effects of Climate Change on Water Resources in the West: Introduction and Overview
Tim Barnett, Robert Malone, William Pennell, Detlet Stammer, Bert Semtner, and Warren Washington
Climatic Change 62: 1-11, 2004.The results of an experimental ‘end to end’ assessment of the effects of climate change on water resources in the western United States are described. The assessment focuses on the potential effects of climate change over the first half of the 21st century on the Columbia, Sacramento/San Joaquin, and Colorado River basins.
Seasonal Cycle Shifts in Hydroclimatology over the Western United States. (2004). Regonda, Satish K. and Balaji Rajagopalan, Journal of Climate, 18:372-384.
This article is similar to the Mote et. al. article above. The researchers found that there is a strong trend of earlier peak streamflows in the Pacific Northwest due to higher temperatures during March and April.
Covariability of Spring Snowpack and Summer Rainfall across the Southwest United States
David S. Gutzler
Journal of Climate, Volume 12, pp. 4018-4027, 2000.
The Impacts of Climatic Changes for Water Resources of the Colorado and Sacramento-San Joaquin River Basins.
Peter H. Gleick and Elizabeth L. Chalecki
Journal of the American Water Resources Association, OL. 35, NO. 6, December 1999.
Severe Sustained Drought, 1995.
Many studies of the river indicate that drought may be more frequent in the future.
Large-Scale Atmospheric Forcing of Recent Trends toward Early Snowmelt Runoff in California
Michael D. Dettinger, Daniel R. Cayan
Journal of Climate, Volume 8: 606-623, 1994.
The Colorado River Basin and Climatic Change (1993)
An EPA report by Linda Nash and Peter Gleick that uses General Circulation Models (GCMs) to study the sensitivity of streamflow and water supply to variations in temperature and precipitation. (EPA 230-R-93-009)
Climate Variability and the Colorado River Compact: Implications for Responding to Climate Change (1988) by Barbara Brown
Chapter in "Societal Responses to Regional Climate Change" by Michael Glantz, Westview Press.
Effects of a Carbon Dioxide-Induced Climatic Change on Water Supplies in the Western United States (1983) by Roger R. Revelle and Paul E. Waggoner
Chapter from "Changing Climate" by the Carbon Dioxide Assessment Committe, Board on Atmospheric Sciences and Climate. This is a dated, but interesting assessment of how climate change could affect the Colorado River Basin. It uses the relationships between temperature, precipitation and runoff to show that warmer air and a slight decrease in precipitation would reduce both the quantity and quality of water resources in the western US.
Geohydrological Implications of Climate Change on Water Resources Development (1979) by Charles W. Stockton and William Boggess.
The first detailed study on what different future climates might mean for the runoff in the United States. At the time of the study a cooling trend had been noted beginning in the 1940s and scientists were also first raising concern about long term warming possible from rising concentrations of greenhouse gases. The study thus considered four cases: warmer and wetter, warmer and drier, cooler and wetter, and cooler and drier for 18 different regions in the U.S. The Colorado River results were presented in two regions, Upper Colorado and Lower Colorado. Charles Stockton is also the author of the now famous 1976 tree-ring study of the Colorado River.
Impact on the Colorado River Basin and Southwest Water Supply (1977) by John Dracup in Climate, Climate Change and Water Supply, National Academy of Sciences, 1977.
This is the first known article on climate change and the Colorado River. In this short article, Dracup provides an overview of the Colorado River including geography, legal framework, runoff, energy, flow augmentation, and finally the potential effects of drought.
Climate Change Conferences
Urban water supplies and climate change in the west. (invite only) Sept. 22-23, 2005 Southern Nevada Water Authority
Impacts of Climate Change on the Hydrology of the Colorado River System(2002)
Poster by Niklas S. Christensen and Dennis P. Lettenmaier from the University of Washington.
Assessing the Hydrological Impacts of Climate Change on the Colorado River Basin
Ongoing research by Niklas Christensen of the University of Washington's Land Surface Hydrology Group, Department of Civil and Environmental Engineering.
Studies about municipalities (alphabetical by state):
California
Progress on Incorporating Climate Change into Management of California’s Water Resources
Technical Memorandum Report, California Department of Water Resources, July 2006
Climate Warming and Water Supply Management in California
White Paper, California Climate Change Center
CEC-500-2005-195-SF, March 2006
Estimated impacts of climate warming on California water availability under twelve future climate scenarios
Zhu, T., Jenkins, M.W., Lund, J.R.
Journal of American Water Resources Association 41 (4), pp. 899-91, October 2005
Department of Civil and Environmental Engineering, University of California-Davis, 1 Shields Avenue, Davis, CA 95616, United States
Climate Change and California Water Resources: A Survey and Summary of the Literature
Michael Kiparsky and Peter H. Gleick, Pacific Institute for Studies in Development, Environment and Security
California Water Plan Update 2005
The Pacific Institute surveyed existing literature on climate change and its impacts on water resources in California. The study reviewed projected effects of climate change on the state’s water supply, delivery, and quality, and explored the economics involved in meeting the challenges that those affects could bring about.
Optimization of California’s Water Supply System: Results and Insights
Marion W. Jenkins, Jay R. Lund, Richard E. Howitt, Andrew J. Draper, Siwa M. Msangi, Stacy K. Tanaka, Randall S. Ritzema, and Guilherme F. Marques
Journal of Water Resources Planning and Management, pp. 271-281, July/August, 2004.
Florida
South Florida Water Management District Draft Environmental Report 2007. See Appendix 2.2 for a discussion of climate change issues.
New Mexico
The Impact of Climate Change on New Mexico’s Water Supply and Ability to Manage Water Resources, July 2006
New Mexico Office of the State Engineer/Interstate Stream Commission
John R. D’Antonio, P.E., State Engineer
Summary
This is a report produced by the New Mexico’s Office of the State Engineer in response to an October 2005 climate change initiative sponsored by Governor Bill Richardson of New Mexico. Recognizing that climate change in New Mexico will largely be impacts on water resources, an analysis of the impact of climate change on water supplies as well as ability for the state to adopt adaptive management strategies was decreed by Governor Richardson in his October 2005 Executive Order. This report gives a summary of projected impacts on New Mexico’s water resources and addresses multiple inter-agency mitigation strategies to effectively and wisely use and allocate New Mexico’s water resources.
New York
Climate Change Impacts on New York City’s Water Supply System
Blake, R., Khanbilvardi, R., and Rosenzweig, C.
Journal of the American Water Resources Association (JAWRA), Volume 36, No. 2, April 2000
Oregon
Portland Climate Change Impacts
The Impacts of Climate Change on Portland's Water Supply: An Investigation of Potential Hydrologic and Management Impacts on the Bull Run System. (2002). Palmer, R.N., and M. A. Hahn. 2002. Report prepared for the Portland Water Bureau, University of Washington, Seattle. 139 pp.
Washington
Seattle Climate Change Impacts
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