Drought conditions will threaten many populated areas

BOB DOUGHTY:A new study shows that long, severe droughts may strike countries with large populations in the not-so-distant future. The study was made for America's National Center for Atmospheric Research. NCAR scientist Aiguo Dai led the research. It shows that drought conditions will threaten most of North and South America by the end of this century. The research found that large parts of Eurasia, Africa and Australia are also at risk. But places from Alaska to northern Europe may get more rainfall and snow. The findings appeared in the publication "Wiley Interdisciplinary Reviews: Climate Change." FAITH LAPIDUS:In the study, Mr. Dai examined rising temperatures linked to climate change. He says the higher temperatures probably will create increasingly dry conditions. He says these conditions will be seen across much of the world in the next thirty years. The scientist also considered the possibility that drought could be much worse by the end of the century. At that time, he says, lack of moisture in many places could be as bad as or worse than any in modern time. He made the predictions after looking at earlier studies and research. His study used modern proposals of possible conditions. It also employed twenty-two computer climate models and a list of drought conditions. The International Panel on Climate Change used twenty-two models in its two-thousand-seven report. BOB DOUGHTY:Mr. Dai said he based the new predictions on the best current projections of carbon dioxide and other gases linked to climate change. The projections are estimates of future amounts of such greenhouse gases. He says many conditions will decide what actually happens. The conditions include natural climate cycles and the amount of greenhouse gases that will be released into the air. Two good examples of such cycles are El Nino and La Nina. They are periodic events that change moisture levels in the atmosphere. FAITH LAPIDUS:The study identified areas threatened with major drying in the future. They include much of Central and South America. Southeast Asia, large parts of southwest Asia, and most of Africa and Australia also will be affected. The research shows that drying in areas along the Mediterranean Sea could also become intense. Other areas were said to expect more moisture. They are much of Scandinavia, Russia, Canada and Alaska. The study shows that some areas of the Southern Hemisphere also may escape drought. BOB DOUGHTY:Do not waste food, and you will save energy. That is the message of scientists who say America wastes food energy equal to about three hundred fifty million barrels of oil a year. That represents about two percent of yearly energy usage in the United States. Scientists Amanda Cuellar and Michael Webber work at The University of Texas at Austin. They reported the findings last month in the journal "Environmental Science & Technology." Mr. Webber says a lot more energy goes into food than people think. His report estimates that, three years ago, between eight and sixteen percent of all energy used in the United States supported food production. FAITH LAPIDUS:The Texas researchers estimated the energy intensity of preparing food from agriculture, transportation, processing and food sales. They also included the energy intensity of storing and preparing food. The researchers measured food intensity in British thermal units, better known as BTUs. A BTU is the amount of heat energy needed to raise the temperature of about one-half kilogram of a substance by one degree Fahrenheit. The scientists say they used information provided by the United States government from nineteen-ninety-five. At that time, the government estimated that twenty-seven percent of food for human consumption was wasted. BOB DOUGHTY:The report said the most wasted foods were dairy products, eggs, fats, grains and oils. Among the least wasted were dry beans, fish, lentils, meat, poultry, peanuts, peas and tree nuts. Last year, a report in the journal PLoS One considered the environmental effects of wasting food. Scientists from the National Institute of Diabetes and Digestive and Kidney Diseases measured the energy content of America's wasted food. They found that American waste of food per person has risen by about fifty percent since nineteen seventy-four. FAITH LAPIDUS:This SCIENCE IN THE NEWS was written by Jerilyn Watson, Caty Weaver and June Simms, who was also our producer. I'm Faith Lapidus. BOB DOUGHTY:And I'm Bob Doughty. Listen again next week for more news about science in Special English on the Voice of America. Source: Voice of America