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Soil microbiologist Ron Turco simulates field drainage conditions in his lab so that he can measure carbon loss in these soil columns. Turco is researching soil management practices that help keep carbon in the soil and out of the atmosphere. (Photo by Tom Campbell) |
Corralling carbon
Many factors affect environmental and climate change research, and that's one reason why researchers from nearly every area of science have joined PCCRC. Ron Turco, Purdue soil microbiologist, is studying some of the smallest environmental elements—microbes that make dead plants decay—and their bearing on climate change.
Turco, along with colleagues Tim Filley and Sylvie Brouder, investigates how carbon is stored in soil, how much escapes into the atmosphere as carbon dioxide and if water leaches carbon out of the soil. Soil carbon is good for plant growth because it builds soil structure and improves nutrient and water retention. Plants capture carbon dioxide from the atmosphere during photosynthesis, and some of the carbon is left as residue when plants die. Soil microbes help generate more carbon dioxide.
“When air comes into the soil through tillage, the microbes become more active and chew on the soil, releasing carbon dioxide, which causes the soil to degrade,” Turco explains. “We want to know how much carbon dioxide comes out of the ground versus how much went in, which tells us how much carbon stayed in the soil.” This information will lead to soil management practices that lock carbon in the soil, called “carbon sequestration.” If more carbon is stored, soil improves, and less carbon dioxide escapes to the atmosphere.
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Global temperatures were higher than average last year, making 2004 the fourth hottest year since the late 1800s. This map shows areas where surface temperatures were warmer (yellows/reds), cooler (blues) or the same as (white) the climatological average. (Graphic courtesy NASA Goddard Institute for Space Studies) |
Arctic meltdown
While Turco's research is centered at ground level, Shepson, a professor of chemistry and earth and atmospheric science, climbs aboard a specially equipped plane that measures carbon dioxide and other greenhouse gases in the lower atmosphere, or troposphere.
Much of his research focuses on the Arctic, where global warming already is causing sea ice to break up earlier in the summer. As the ice melts or floats away, polar bears and seals lose their feeding and breeding grounds. The bears already have 15 percent fewer offspring and are thinner due to a shorter hunting season and less available food.
“The ice in the Arctic potentially will be gone by the end of this century,” says Shepson. “To me, that is an unbelievable catastrophe, because it means no more seals, no more polar bears. The entire ecosystem will be completely changed.”
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