WASHINGTON (AP) — A surprising hot spot of the potent global-warming gas methane hovers over part of the southwestern U.S., according to satellite data. 
 
 This undated handout image provided by NASA/JPL-Caltech/University of Michigan, shows The Four Corners area, in red, left, is the major US hot spot for methane emissions in this map showing how much emissions... (Associated Press) 
 
 That result hints that the U.S. Environmental Protection Agency and other agencies considerably underestimate leaks of methane, which is also called natural gas. 
 
 The higher level of methane is not a local safety or a health issue for residents, but factors in overall global warming. It is likely leakage from pumping methane out of coal mines. While methane isn't the most plentiful heat-trapping gas, scientists worry about its increasing amounts and have had difficulties tracking emissions. 
 
 A satellite image of atmospheric methane concentrations over the continental U.S. shows the hot spot as a bright red blip over the Four Corners area of New Mexico, Colorado, Arizona and Utah. The image used data from 2003 to 2009. 
 
 Within that hot spot, a European satellite found atmospheric methane concentrations equivalent to emissions of about 1.3 million pounds a year. That's about 80 percent more than the EPA figured. Other ground-based studies have calculated that EPA estimates were off by 50 percent. 
 
 The methane concentration in the hot spot was more than triple the amount previously estimated by European scientists. 
 
 The new study, done by NASA and the University of Michigan, was released Thursday by the journal Geophysical Research Letters. 
 
 The amount of methane in the Four Corners — an area covering about 2,500 square miles — would trap more heat in the atmosphere than all the carbon dioxide produced yearly in Sweden. That's because methane is 86 times more potent for trapping heat in the short-term than carbon dioxide. 
 
 "It's the largest signal we can see from the satellite," said study lead author Eric Kort, a University of Michigan atmospheric scientist. "It's hard to hide from space." 
 
 There could be some areas elsewhere in the country where more methane is emitted if it is dispersed by wind, Kort said. 
 
 Kort said the methane likely comes from leaks as workers extract natural gas from coal beds, and not from hydraulic fracturing, called fracking, because the data were collected before fracking really caught on. 
 
 The results were so initially surprising to the scientists that they waited several years and then used ground monitors to verify what they saw from space, Kort said. 
 
 Several methane experts said the research makes sense to them and that the detected methane amount is disturbing. 
 
 "That is immense," Terry Engelder, a scientist at Pennsylvania State University, wrote in an email. 
 
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 NASA's Earth science research: http://www.nasa.gov/earthrightnow 
 
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 Seth Borenstein can be followed at http://twitter.com/borenbears 

 This undated handout image provided by NASA/JPL-Caltech/University of Michigan, shows The Four Corners area — in red, left, is the major US hot spot for methane emissions. 
 
 This undated handout image provided by NASA/JPL-Caltech/University of Michigan, shows The Four Corners area — in red, left, is the major US hot spot for methane emissions. AP 
 
 One small spot in the U.S. Southwest is the surprising producer of the largest concentration of methane gas seen across the nation. 
 
 Levels of methane over the Four Corners region are more than triple the standard ground-based estimate of the greenhouse gas, reports a joint study of satellite data by scientists at NASA and the University of Michigan. 
 
 Methane is a heat-trapping gas whose increasing quantities in the atmosphere have fueled concerns about global climate change. 
 
 The methane “hotspot,” seen on the map as a small red splotch, measures just 2,500 square miles at the junctures of Arizona, New Mexico, Colorado and Utah (for scale, the state of Arizona is about 113,000 square miles). 
 
 But the area generated an annual 0.59 million metric tons of methane between 2003 and 2009 — or, about as much methane as the entire coal, oil, and gas industries of the U.K. give off each year, says the report published in the scientific journal Geophysical Research Letters. 
 
 The hotspot predates the Southwest’s controversial use of hydraulic fracturing. But the zone is over New Mexico's San Juan Basin, home to thousands of wells that pull natural gas from coal beds, the study’s authors say. Natural gas is about 95 to 98% methane, and the authors suggest that the hotspot is best attributed to leaks and errors in the region’s natural gas production equipment. 
 
 “While fracking has become a focal point in conversations about methane emissions, it certainly appears from this and other studies that in the U.S., fossil fuel extraction activities across the board likely emit higher than inventory estimates,” said Eric Kort, assistant professor of atmospheric, oceanic and space sciences at the University of Michigan and the first author on the paper. 
 
 "There's so much coalbed methane in the Four Corners area, it doesn't need to be that crazy of a leak rate to produce the emissions that we see,” added Kort. “A lot of the infrastructure is likely contributing.”
– Put together all the methane produced by the coal, oil, and gas industries each year across the UK, and you'll have a good estimate of the amount produced in a small stateside area between 2003 and 2009. The 2,500-square-mile Four Corners region—where Arizona, Colorado, New Mexico, and Utah meet—is responsible for triple the "standard ground-level estimate" of methane in the US, Time reports, via a NASA and University of Michigan study. That region produced 0.59 million metric tons of the gas, which is associated with climate change worries, during that six-year period. And the area has produced plenty of methane since before modern fracking began, suggesting another process may be to blame. Researchers point to natural gas extracted from coal beds in the area: "Thousands of wells" are engaged in the effort, and natural gas is between 95% and 98% methane, Time notes. The study, which used satellite imagery, suggests that officials are way underestimating methane leaks, the AP reports. But local residents needn't panic: Though methane is a global warming risk, it doesn't threaten health or safety in the area, the AP notes. Another big methane spot: the floor of the Atlantic, which keeps "burping" up the stuff, experts say.