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Climate change researcher Paul Shepson uses this specially equipped light airplane to measure greenhouse gases in the Earth's lower atmosphere. (Photo by Tom Campbell) |
Shepson also investigates how forests affect carbon dioxide in the atmosphere and how carbon dioxide influences vegetation. “The future of the climate depends on us understanding when we emit carbon dioxide and where it goes,” he says. “Some of it goes into the ocean, some goes into making trees and some stays in the atmosphere. We need to better understand how human activities can affect the health and vitality of forests.”
Shepson and his team use the Airborne Laboratory for Atmospheric Research to gather data on the rate at which carbon dioxide goes into the forest, and how much comes out after trees have used it for photosynthesis.
Land-water linkages
Environmental and climatic changes also affect crop location and yield, and land use. Land and how water moves through it, or hydrology, and the effect each has on the other also are part of climate and environmental change. Agronomy researcher Laura Bowling focuses on these factors. She measures stream flow, snow depth, snow extent and soil moisture across a watershed in an effort to predict how hydrology will be affected, particularly in cold region environments such as the Arctic.
“Land surface changes that already can be observed are consistent with climate models that predict that the largest temperature changes will be in the Arctic and high latitudes,” she says. “Changes in the Arctic are of great concern. It's an ecosystem that won't easily go back to the way it was. Warming has the potential to make dramatic changes over the next few generations. I don't really care if the climate was warmer 130,000 years ago. I care that it will be a lot warmer 50 years from now.”
Bowling believes it's important to simulate land use hydrology so that researchers can accurately predict water availability in steams and other sources. “Then, you can operate in a manner to better provide for agriculture and human consumption in the future,” she says.
Indiana state climatologist Dev Niyogi says PCCRC scientists study all aspects of climate change, not just warming and cooling. “Climate changes that affect Indiana might mean changing crops or harvesting dates,” he says. “If we see differences in pollution, the region's nutrient cycle, hydrology and land use might also be changing.”
It's more than weather
Changes in food production are bound to affect the world economy. The Purdue-based Global Trade Analysis Project (GTAP) manages a global database composed of 87 countries or regions and 57 economic sectors. The data it collects helps researchers predict the economic impact of climate change.
“If agronomists tell us that corn yields will drop 20 percent in the Midwest but increase 8 percent in southern Canada, then we can estimate changes in production, consumption and trade for each region of the world,” says agricultural economist and GTAP co-director Wally Tyner. “It's never adequate to examine direct impact alone because all economies are linked. Since climate change is global, there may be costs in one region and benefits in another.”
Like the environment and the economy, human health is not immune to climate change either. While greenhouse gases aren't solely responsible for respiratory ailments such as asthma, they are major contributors, especially ozone, which comes from burning fossil fuels. The Centers for Disease Control and Prevention report that 20.3 million Americans have asthma, an illness that is growing at an alarming rate in children.
Infectious diseases also are a major threat as warmer temperatures creep toward both the Arctic and the Antarctic and to higher elevations. Disease-carrying mosquitoes and other pests and pathogens that affect plants, humans and animals are more widespread, finding homes in previously inhospitable areas.
The rapid spread across North America of West Nile virus, which first appeared in the United States in 1999, is one example and hints at the influence of climate change, scientists say. Malaria, the world's deadliest disease, has increased rapidly in the past few years, killing approximately 3 million people in 2002, with another 300 million sickened. California, Florida, Georgia, Michigan, New Jersey and New York all recorded cases of the illness, which had not been seen in the United States for more than 20 years.
“The Earth's climate is changing, and the results are having an enormous impact on the biology of our planet,” says Shepson. “Climate change may be the most important issue we face as a species.”
Related links:
Department of Agricultural Economics
Department of Agronomy
Indiana State Climate Office
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