Here is what the Colorado State Water Board is up to:

STATE WATER BOARD REPORT:
Climate Change Will Affect Water Supply Planning

The Colorado Water Conservation Board (CWCB) recently released a report titled “Colorado Climate Change: A Synthesis to Support Water Resource Management and Adaptation.” The report focuses on observed trends and projections of temperature, precipitation, snow and runoff. The report was released in connection with the Governor’s Conference on Managing Drought and Climate Risk, held October 8-10, 2008, in Denver.

“This report provides the physical science basis to support Governor Ritter’s Climate Action Plan and state efforts to develop water adaptation plans to respond to changes in climate that cannot be avoided,” said Jennifer Gimbel, Director of the CWCB. This new scientific assessment of Colorado climate change was prepared by the Western Water Assessment (WWA), a University of Colorado-National Oceanic and Atmospheric Administration partnership, and included scientists from the NOAA Earth System Research Laboratory, the CU Cooperative Institute for Research into Environmental Sciences, and Colorado State University Colorado Climate Center.

According to observations cited in the report, Colorado’s temperature has increased about 2° F in the past 30 years.  Across the Western U.S., the buildup of greenhouse gases in the atmosphere is responsible for about 1° F of this warming, according to modeling studies, and the remaining increase may be due to natural variation.

Computer models project Colorado’s temperature will warm 2.5° F by 2025 and 4° F by 2050. The implications of this are that typical Colorado summer monthly temperatures will be as warm or warmer than the hottest 10% summers, between 1950-1999. By the mid-21st century, current climate regimes may shift, bringing the temperature regimes of the Kansas border westward and upslope to the Front Range, and the climate of the desert Southwest may creep into Western Slope valleys. Although winters warm, high-elevation winter temperatures are projected to remain well below freezing, preserving the bulk of the state’s crucial snow pack, which lies above about 8,000 feet.

Observed precipitation variability is high and no consistent precipitation trends have been detected. Model projections of precipitation show little change in annual average precipitation, however, temperature increases alone will have significant impacts on snow and water resources. Earlier spring melt, increased evaporation, and drier soils will reduce runoff for most of the state’s river basins, with a 5% to 20% loss in the Colorado River Basin by the mid-21st century. The start of the spring stream flow from melting snow has already shifted about two weeks since 1978, the result of warming spring temperatures and late summer flows have decreased.  This report suggests a reduction in total water supply by the mid-21st century. The overwhelming majority of studies agree on those trends.

“The population and the environment of Western states depend on water from Colorado’s rivers,” said Brad Udall, director of the Western Water Assessment. “This report gives water resource managers a synthesis of the best scientific knowledge of what is expected for Colorado’s climate over the next few decades to help them plan now for drought and adaptation to climate change.”

CWCB was created in 1937 for the purpose of aiding in the protection and development of the waters of the state. The agency is responsible for water project planning and finance, stream and lake protection, flood hazard identification and mitigation, weather modification, river restoration, water conservation and drought planning, water information, and water supply protection.