“We didn’t focus on it because we weren’t sure if it was a true signal or an instrument error,” said Christian Frankenberg, a research scientist at NASA’s Jet Propulsion Laboratories in Pasadena, California, in an article on NASA’s news website
Methane gas is the most potent of the so-called “greenhouse gases” that trap the Earth’s heat and contribute to global climate change. Carbon dioxide, another greenhouse gas, is far more plentiful in the atmosphere, but methane is about 80 percent more efficient at trapping heat than carbon dioxide, according to an article on The Atlantic’s CityLab website
An article on the Christian Science Monitor
website says that the 2,500-square mile methane cloud over the region where Arizona, New Mexico, Colorado, and Utah meet traps more heat in a year than all the annual carbon dioxide emissions of Sweden.
The change of heart by NASA scientists is described in a new study published Friday in the journal Geophysical Research Letters
which took another look at the earlier data, and confirmed the existence of North America’s largest methane “hotspot.”
The source of the methane is believed to be extensive coal-mining activity in the San Juan Basin, according to Eric Kort, a professor of Atmospheric, Oceanic and Space Sciences at the University of Michigan in Ann Arbor and lead author of the study. He calls the Basin “the most active coalbed methane production area in the country.”
The study shows that there were 0.59 million metric tons of methane released every year during the period 2003-2009, 3.5 times more than earlier estimates.
There is currently a sharp increase in hydraulic fracturing – commonly called fracking – in the region, but because the cloud predates the fracking activity, Kort and Frankenberg say the earlier coal-mining activity is most likely to blame.
“The results are indicative that emissions from established fossil fuel harvesting techniques are greater than inventoried,” Kort said. “There’s been so much attention on high-volume hydraulic fracturing, but we need to consider the industry as a whole.”