With projected 25-percent and 50-percent increases in U.S. and world populations, respectively, by 2050, substantial increases in freshwater use for food, fiber, and fuel production, as well as municipal and residential consumption, are inevitable.

This increased water use will not come without consequences, and as one of the largest users of water in the United States, agriculture will be impacted significantly by changes in water availability and cost. An abundant, reliable supply of water to meet demands cannot be taken for granted.

To evaluate current trends, summarize key vulnerabilities, and identify possible solutions to current and future challenges, CAST convened a Task Force of eight scientists, educators, and resource analysts who have prepared a new CAST Issue Paper: "Water, People, and the Future: Water Availability for Agriculture in the United States."

Through case studies, the new CAST publication discusses the diverse demands for water resources using the impacts, regulations, challenges, and policies of four specific areas of the United States -- California, Arizona, Florida, and the High Plains -- with particular focus on the implications for agriculture.

"It is critical that policymakers, water managers, and water users work collaboratively to achieve sustainable water resource management," says Task Force Chair Sharon Megdal, Water Resources Research Center, University of Arizona, Tucson. "Multiple issues require attention -- water quality, environmental water needs, municipal demands for water, water resource availability, agricultural water use -- and no issue can be addressed individually. Supplying future water demand requires continued investments and efforts to enhance water use efficiency. Difficult social and economic transitions and tradeoffs may lie ahead."

John Bonner, CAST executive vice president/CEO, concludes: "Using science as its foundation, CAST provides this timely resource to assist in understanding the complexities surrounding this serious challenge to Earth's resources."

The full text of Water, People, and the Future: Water Availability for Agriculture in the United States (Issue Paper 44, 20 pp.) may be accessed free of charge on the CAST Web site (http://www.cast-science.org/), along with many of CAST's other scientific publications. The paper also is available in hard copy for a shipping/handling fee.

CAST is an international consortium of 32 scientific and professional societies. It assembles, interprets, and communicates credible science-based information regionally, nationally, and internationally to legislators, regulators, policymakers, the media, the private sector, and the public.