Coal, not fracking blamed for U.S. methane hot spot

A tiny patch of the southwestern U.S. produces the nation’s highest concentrations of methane, the potent greenhouse gas that President Barack Obama has vowed to tackle as part of his assault on climate-change pollution.

The hot spot near the intersection of Arizona, Colorado, New Mexico and Utah accounts for almost 10 percent of all methane from natural gas in the U.S., researchers said in a paper published today by the journal Geophysical Research Letters. The area, about half the size of Connecticut, is a major source of gas harvested from coal mines, according to a National Aeronautics and Space Administration statement announcing the study.

The gas measured in the study comes from leaks in processing equipment. Environmental groups have pushed Obama to regulate methane leaks as drilling using hydraulic fracturing has boomed. Eric Kort, the paper’s lead researcher, said it’s a mistake to focus only on fracking rather than existing industries.

The results indicate “that emissions from established fossil fuel harvesting are greater than inventoried,” Kort, an atmospheric researcher at the University of Michigan, said in the statement. “There’s been so much attention on high-volume hydraulic fracturing, but we need to consider the industry as a whole.”

Natural gas is about 98 percent methane, according to NASA, which assisted in the study. While less long-lived than carbon dioxide in the atmosphere, methane is about 25 times more potent in trapping heat.

The study, based on satellite data, found the 2,500-square mile (6,500-square kilometer) “hot spot” produced about 590,000 metric tons of methane annually from 2003 to 2009, according to the NASA statement. That is more than triple previous estimates of emissions from the area, highlighting the need for better monitoring, the researchers said.