Current research by ISU scientists may help curb global warming and offer Iowa farmers new uses for their land. Lee Burras, assistant professor of agronomy, said research is being conducted in the Chariton Valley in southern Iowa that involves the sequestering, or storing, of carbon dioxide by growing trees and perennial grasses, such as switchgrass. Carbon dioxide has increased dramatically in the atmosphere over the past 150 years, Burras said. This increase, he added, is largely due to the burning of fossil fuels, such as coal and petroleum. With the build up of carbon in the atmosphere, the earth also has experienced an extreme warming trend, Burras said. While some scientists believe this global warming may be part of a natural cycle, he said a growing number of scientists now attribute the warming trend to increased atmospheric carbon. Gene Takle, professor of agronomy and geological and atmospheric sciences, said it is hard to dismiss the present warming as a natural occurrence. “The last 100 years show an abrupt increase in earth temperature,” Takle said. “No natural process would lead to this.” However, a solution may be growing in Iowa’s fields, Burras said. “We have more carbon in the atmosphere than we want,” he said. “The best way I understand to get it out is through plant growth.” Burras said green plants absorb carbon dioxide from the atmosphere during photosynthesis. The carbon is first stored in the plant. If plants, such as trees or certain perennial grasses, are left undisturbed for a number of years, the carbon eventually will work its way into the soil and remain stored there until the ground is cultivated. He said when annual crops such as corn and soybeans are grown, the ground is cultivated each season and carbon dioxide is recycled. The carbon drawn from the atmosphere during photosynthesis is released again when the ground is cultivated. Burras said the practice of no-till farming slows down the process of carbon reentering the atmosphere. However, if increased acres of land were planted with trees and perennial grasses, greater amounts of carbon could be stored for a long period of time, he said. Takle said there is no hope of slowing down the atmospheric carbon build-up in the next 50 years. “A lot of work like Lee [Burras’] needs to be done to see what we can do about this whole problem of atmospheric carbon build up,” he said. Mike Duffy, professor of economics, said it will take time for farmers to begin reaping economic benefits from carbon sequestering. For one thing, he said, it might be hard to convince a farmer who traditionally has grown corn and soybeans to plant trees instead. Duffy said he believes farmers will be paid a green fee for overall good conservation practices. He said these practices would include conserving soil and water, preserving wildlife habitat, maintaining high air quality standards and sequestering carbon.