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June 24, 2012

From anthropologists to zoologists, dozens of UGA scientists are in agreement: the reality of climate change is no longer a debatable issue. According to these researchers, climate change is real, most of it driven by rising concentrations of heat-trapping greenhouse gases from human activities, such as fossil fuel burning and deforestation. The task now is to learn how to cope with the resulting adversities, which include hotter temperatures, prolonged droughts and coastal flooding.

UGA climatologist and geography professor Marshall Shepherd said, "Human-related activities are a clear contributor to climate change along with natural variability, and changes are happening on time scales much shorter than those of natural changes."

The evidence, some of it from UGA scientists, indicates that climate-change impacts are already upon us. The sea level is rising, and 10 of the planet's warmest years (in terms of global average temperature) on record have occurred during the past 12. Moreover, some of the impacts are occurring sooner than expected. Thawing of the Greenland and Antarctic ice sheets have accelerated, and the extent and thickness of Arctic sea ice is rapidly declining. "People are sailing in the Arctic Ocean now. We're talking about now, not 50 years from now," says Shepherd, president-elect of the American Meteorological Society.

"The climate is changing quickly; it's here, it's real," said James Porter, assistant professor in the Odum School of Ecology, "and the rate of change will only accelerate during the next 50 years. He notes that climate scientists a few years ago were predicting the Arctic Ocean would be ice-free during summers by 2040. Now, the forecast is that it may occur in this decade.

Campus-wide, at least 70 UGA faculty members from an array of disciplines are engaged in climate-change research. In the ecology school, the entire faculty is involved, said Porter. No other issue has galvanized scientists from so many different backgrounds as climate change. The widespread interest prompted a core group of researchers in 2010 to launch the Georgia Initiative for Climate and Society, sponsored by UGA's Office of the Vice President for Research. The initiative's overarching goals, said director Patricia Yager, an oceanographer in the department of marine sciences, are "to understand what's coming and to start planning for adaptation and mitigation."

That is the aim of the bulk of UGA's investigations-deciphering the consequences of a warmer planet and determining how society can grapple with them. "There will be really dramatic changes that we have to prepare for," said Ron Carroll, director for science at UGA's River Basin Center, which is studying the possible effects of climate change on Georgia's rivers, streams, and coastal communities. He and other scientists point out that while there are still limits to their knowledge of the extent and intensity of climate change, they can draw some preliminary conclusions from computerized climate models, remote-sensing data, coring samples, tree-ring information and other sources.

The data paint a grim picture of what's in store for Georgia through the end of this century, according to the university's researchers and reports from the U.S. Global Change Research Program, the National Oceanic and Atmospheric Administration (NOAA), NASA, and other sources. Average temperatures in the state are predicted to rise as much as five degrees Fahrenheit by mid-century and up to nine degrees by 2080. Droughts will be more severe, and longer lasting. Rainfall patterns will change-the time between rain events will increase, and when it does come, the rain will fall in heavier downpours that cause more storm runoff and erosion. Summer river flow will decline and some rivers may dry up altogether, exacerbating already serious squabbles over water supply. The number of days with 90-degree-plus temperatures could increase from about 60 days a year to as many as 135 days a year. Diseases such as dengue fever and cholera could become serious public health threats. Heat-related health problems such as sunstroke would rise. The floral and faunal diversity of forests and other ecosystems could change substantially.

On Georgia's coast, the most ominous threat is a sea-level rise of as much as three feet by the end of this century, the result of thawing glaciers and warmer seawater. The higher seas could put as much as 50-100 square miles of currently dry coastal land under water at high tide, according to some computer models. UGA River Basin Center scientists are producing maps to show where the flooding is expected. The researchers hope that coastal residents, developers, and elected officials will use these maps to make sound land-use decisions.

UGA's climate-change research is not confined to Georgia and the Southeast. Several of the university's scientists are conducting studies around the world to discern a global picture of climate change. Yager, for example, is investigating how an altered climate may affect the oceans in Antarctica, the Arctic, and the Amazon River. UGA climatologist Thomas Mote, head of the department of geography, has been closely monitoring the two-mile-thick Greenland ice sheet. He and colleagues reported last year that the melting is speeding up, and a likely reason is human-induced climate change. Chris Cuomo, professor of philosophy and director of UGA's Institute for Women's Studies, is keeping track of how the Inupiaq people of northern Alaska are coping with melting ice caps, thawing permafrost, and other calamities that are jeopardizing their way of life.  Erin Lipp, an environmental microbiologist in UGA's Department of Environmental Health Sciences, and colleagues made international headlines last year when they reported that the growth and spread of harmful Vibrio bacteria in coastal waters of the Southeast may be enhanced by climate change in western Africa's Sahara desert. Lipp concluded that iron-laden dust blows from the Sahara region across the ocean and settles in U.S. coastal waters, where the iron can stimulate rapid and abundant growth of the bacteria. Various Vibrio species can cause life-threatening gastrointestinal ailments, including cholera, and Vibrio cases have jumped 85 percent in the U.S. in the past 15 years.

Some UGA scientists have devised elaborate experiments to help predict the impacts. One of them is being carried out in a remote section of UGA's Whitehall Forest, four miles from downtown Athens. Ecosystems ecologist Jacqueline Mohan and her graduate assistants maintain several living-room-size plots, enclosed by plastic fences, where the soil stays six to 10 degrees Fahrenheit warmer than the natural ambient temperature. Growing in the various plots are several native tree saplings-tulip poplar, longleaf pine, Southern magnolia, maples, oaks, and others. The extra warmth is delivered via black electric cables buried five inches in the soil. Electronic monitors continuously measure temperature, moisture, respiration, and other variables to help determine how the trees, soil, and microbes-even earthworms-respond to the higher temperatures. From the experiment, Mohan and her colleagues hope to learn how a hotter climate might affect the vast forests of Georgia and other Eastern states.

Implementing new forest-management strategies, forestry experts say, might boost the ability of southeastern forests to adapt to the predicted drought stress and hotter temperatures of climate change. To help develop such strategies, the U.S. Department of Agriculture has awarded a $1.34 million grant to several researchers in UGA's Warnell School of Forestry and Natural Resources.

Other UGA researchers are trying to develop strategies to help Georgia and other states deal with one of the most crucial challenges of climate change-ensuring adequate water supplies. Even as climate experts predict decreased water availability for Georgia in coming decades, the state faces demands for more water from agriculture, industry, power generation, and a rapidly growing population. To help quench future thirst, Carroll at UGA's River Basin Center is studying, among other things, the use of "constructed wetlands"-such as human-made marshes and swamps-to treat and store storm water and wastewater. Such artificial wetlands, he said, could help rivers and streams continue flowing even during drought.

Although the inevitability of climate change is clear, major questions remain: Are the more dire consequences of climate change inevitable? Or is there still time to prevent them? At this point, answers are elusive. Most scientists concur that preparations should begin now for climate upheaval.  Remarked Shepherd, "I do think we are experiencing the beginning of the 'new climate.'"