Report Assesses Impact of Climate Change; Researchers Invite Public Comment

Lori Stiles
June 12, 2000

Tamara Wilson, 520-622-9001,
William A. Sprigg, 520-621-7331,

Report website:

TUCSON, Ariz. -- Researchers from the University of Arizona who direct a project to assess how future climate change could affect the economy, environment and quality of life in the American Southwest have released a draft report on the Internet for public review and comment.

The report, the Southwest Assessment Summary Report, will be part of a national report to be presented to Congress next year. The draft national report was released in briefings to the House and the Senate and for public comment today, June 12.

"Public feedback is an important part of the Southwest assessment project, as the final document will be used by many local, state, and federal policymakers whose decisions will directly affect residents throughout the Southwest," said Tamara Wilson of UA's Institute for the Study of Planet Earth (ISPE).

The U.S. Geological Survey and the Office of Global Programs in the National Oceanic and Atmospheric Administration co-sponsor the regional report.

William A. Sprigg, associate director of ISPE, and Todd Hinkley of the U.S. Geological Survey directed the study, which involved intensive collaboration among authors, experts and specialists from academia, private industry, and government agencies.

The draft document is on the Internet at the ISPE/Southwest Regional Climate Change Assessment Project website. Public comment through July 10, 2000, should be directed to Tamara Wilson, ISPE, 715 N. Park Ave. 2nd Floor, Tucson, Az. 85721-0156, or by e-mail to Wilson at

The report covers several key issues crucial to the continued sustainability of life in this region. These include:

*Water. No resource in the Southwest generates as much debate and conflict as water. Climate variability directly affects many of the region's water supplies, as surface delivery systems depend on annual rainfall amounts and evaporative loss. Ground water levels and supplies also depend on the infiltration of rain water back into the water tables in the ground. The Southwest has seen wetter and dryer periods in the past. Current climate models indicate wetter and warmer periods for the future.

*Ranching. Arizona ranching depends on natural vegetation. This makes ranching particularly sensitive to fluctuations in precipitation and temperature. But sorting out the implications of climate variability on ranching is complicated by urban expansion, environmental conflict, and market pressures.

*Natural ecosystems. Climate variability and change affects each ecosystem in the Southwest differently. Species and environments will respond in varying degrees to changes in rainfall, temperature, and increasing carbon dioxide levels. Ecosystem response to climate can include changes in fire frequency and intensity, threats of desertification, and the potential reactivation of sand dunes in the region.

*Mining. Changes in climate can affect the water and land resources used in mining. For example, too much water from increased rainfall can cause holding ponds to overflow. Overflows from these ponds can contain highly toxic chemical and metal pollutants that may enter local environments and leak into waterways. As some rural economies in the Southwest are primarily supported by local mining operations, any climate-related changes affecting the efficiency of mining becomes a critical issue. By anticipating these changes, mining interests can prepare and handle whatever climate changes may occur.

*Human health. As climate varies and changes over time, human beings are forced to adapt to resulting changes in their living environments. Warmer temperatures can lead to heat-induced illnesses. Dryer conditions can lead to breathing difficulties, compounded by increases in the amount of dust in some areas. The report addresses two climate-related human health issues in depth: Valley Fever and Hantavirus Pulmonary Syndrome (HPS).

*Urban areas. Urban areas are also susceptible to climate variability. Electrical storms, floods, extreme heat, and high winds may result in injury or death, property damage or loss, and damage to natural ecosystems. Such threats to human life and health, fresh water supplies, economic activity, public infrastructure, and private property may be countered with appropriate planning.

*Energy. High temperatures increase electricity demand for cooling. If model projections are right, the Southwest could see increases in the frequency and duration of extremely hot summer months. Power plants will have to increase capacity to supply the increased energy demands. Higher temperatures also increase evaporation, transpiration by plants, and water use for irrigation.

***(EDITORS: UA News Services also released this story on the Newstips listserv.)***


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