By Sharon Omahen
University of Georgia
Monique Leclerc and Anandakumar Karipot don’t just discuss global
warming. They help measure the gases responsible for it.
Specifically, they’re building the
tools to measure the flow of greenhouse gases.
This month, they’re starting a three-year study in Southeastern
forest canopies with a $603,000 grant from the U.S. Department of
Energy.
Leclerc is a professor and Karipot an assistant research
scientist with the University of Georgia College of Agricultural
and Environmental Sciences. Both work in the UGA Laboratory for
Environmental Physics on the CAES campus in Griffin, Ga.
Climate change and greenhouse gases
“Our lab has done a lot of research into improving methods of
evaluating the amount of carbon sequestered in plant canopies,”
Leclerc said. “The (U.S.) Department of Energy is very interested
in this type of research because climate change is such a big
concern.”
Greenhouse gases absorb and hold some of the heat radiating from
the earth which causes the air temperature to rise. In a
nutshell, that’s the “greenhouse effect” involved
in global warming.
Plants take in carbon dioxide, a key greenhouse gas. They use the
carbon in the CO2 molecules as building blocks in
their growth.
Over countless years, vast amounts of plants residues form coal,
oil and other fossil fuels. Burning these
fuels releases CO2 back into the air.
But how much carbon does the burning release into the air? And
how much do plants take out, and how fast do they do it?
How many more trees will help?
Pinpointing answers to these questions will help scientists know
how many trees, crops and other plants are needed to take out the
carbon all that fuel-burning is putting into the air.
Leclerc said scientists are studying many aspects of climate
change worldwide. But they still don’t know enough for their
measurement tools to be truly accurate.
“As a nation, we need to know how much carbon is taken up by
different ecosystems,” she said, “and then pull this information
together at a continental level.”
With the DOE grant funds, Leclerc and Karipot will work with
researchers at the University of California at Berkeley,
University of New Hampshire, University of Florida and Brookhaven
National Laboratory.
“We will release six different tracers inside the canopy and then
trace their movement,” she said. “Tracers are substances that can
easily be traced using very sophisticated tracking devices.”
Leclerc and her colleagues will be using perfluorocarbons,
manmade gases, as tracers. They will release them at different
levels in forest canopies and then monitor how fast they move and
where.
“The concept is exactly the same in corn, sorghum or cotton field
canopies,” she said. “It would just be more difficult to track in
these plant canopies because the instruments would have to be
very, very small.”
Russ Dietz, an atmospheric tracer scientist from the
Brookhaven Lab in New
York is one member of the team. “He is truly the best in the
world in his field,” Leclerc said.
Improving the current tracking model
The team’s main goal is to test and improve a model for tracking
gases like carbon dioxide within and above plant canopies.
“The long-term view is to mitigate climate change,” Leclerc said.
“We have to have a better knowledge of where gases come from in
order to measure things like carbon fluxes.”
Leclerc and Karipot have been studying the exchange of gases
between vegetation and the atmosphere for years.
“When I was working on my master’s degree in Canada, the
CO2
level over the corn field was 325 parts per million,” Leclerc
said. “(It) would now be 355 ppm over that same field.”
Americans could help reduce carbon in the air by driving smaller
cars. “But no one wants to give up their SUV,” she said. “Climate
change is here to stay, and it’s a real problem. As a scientist,
I’m truly concerned.”
