Radiometers are among the many instruments at ARM’s Southern Great Plains observatory used by scientists to measure the greenhouse gas effect. Photo by the U.S. Department of Energy Atmospheric Radiation Measurement Climate Research Facility
April 2 (UPI) -- For the first time, scientists have directly measured methane's growing greenhouse gas effect at Earth's surface.
Data collected at a Department of Energy field observation site in northern Oklahoma captured the warming effect of methane over a ten year period. When researchers with the Lawrence Berkeley National Laboratory analyzed the data, they found methane concentrations in the atmosphere and the greenhouse gas both held steady in the early 2000s but began to rise simultaneously beginning in 2007.
"We have long suspected from laboratory measurements, theory, and models that methane is an important greenhouse gas," Dan Feldman, a researcher at Berkeley Lab, said in a news release. "Our work directly measures how increasing concentrations of methane are leading to an increasing greenhouse effect in the Earth's atmosphere."
The molecules of greenhouse gasses like methane, CO2 and water vapor absorb the sun's energy with greater efficiency than other molecules, trapping heat inside the atmosphere and causing both Earth's land and ocean surfaces to warm.
Numerous climate change computer models and lab experiments have predicted methane's significant greenhouse gas effect, but the latest findings, published this week in the journal Nature Geoscience, are the first to showcase the effect outside the lab.
Instruments at the DOE's Atmospheric Radiation Measurement facilities helped scientists directly measure the absorption of specific frequencies of solar rays by local methane.
Scientists working on the DOE ARM program operate three long-term atmospheric research observatories: the Southern Great Plains observatory in Oklahoma, the North Slope of Alaska observatory in the Far North of Alaska and the Eastern North Atlantic observatory on the Azores Islands.
Researchers hope the data collected at these three observatories will help climate scientists more closely track the relationship between greenhouse gas concentrations in the atmosphere and the rise in surface temperatures across the globe.