Vast Methane Cloud Confirmed Over the American Southwest

At first NASA scientists didn't believe it, thinking it was an instrument error. But then came the confirmation. They had found a Delaware-sized methane cloud over the American Southwest at the Four Corners. At 2,500 square miles, it is the largest concentrated area of methane emissions in the United States.

Methane, also known as natural gas, is a powerful greenhouse gas -- 20 times more potent than CO2.

The gas isn't coming from hydraulic fracturing well leaks, which are indeed a source of methane emissions. The data shows the Four Corners methane cloud pre-dates the fracking boom. So, it's not from fracking or cow farts. This methane cloud is believed to be coming from leaks from coalbed methane extraction.

Leaks. It's because of such inevitable leaks that it's worth taking it with a grain of salt when natural gas is billed as a solution to climate change for its lower CO2 emissions.

Carbon dioxide gets most of the attention in the fight against climate change. Human activity worldwide pumps about an additional 29 gigatons of CO2 into the atmosphere every year -- about 60 percent of which lingers there, building up year after year. CO2 accounts for about 80 percent of the greenhouse gas emissions in the U.S.  And it can stay in the atmosphere for as long as 200 years.

Meanwhile, methane accounts for only 9 percent of U.S. emissions. The bad news is it's 20 times more potent as a greenhouse gas, pound for pound. Despite that I suspect the reason we're so focused on CO2 is that the stuff stays in the atmosphere for so long. Methane hangs around for just 12 years. Still, if we're looking to send the climate over the cliff and ignite negative feedback loops (such as methane-emitting permafrost melt), methane emissions are just the thing to pile on to an already dire situation.

The Four Corners methane cloud is emitting nearly 14.8 million metric tons of methane per year, and yet it's by no means the largest source of methane emissions in the United States. By itself it's nearly as significant as emissions from all the forestry in the United States (15 million metric tons/year). However, it's still dwarfed by such sources as energy (229.6 million metric tons/year), agriculture (117.2 million metric tons/year), or landfills (62.5 million metric tons/year).

More significantly, however, this vast methane cloud appears to be a byproduct of extracting natural gas from a coal bed. More specifically, it's coming from leaks in the process -- apparently huge leaks. While natural gas is billed as safer for the environment because of reduced CO2 emissions, it's worth taking a serious look at whether or not that reduction in CO2 is negated by an increase in the significantly more potent methane. Even with modern hydraulic fracturing, some researchers such as Dr. Anthony Ingraffea are suggesting well failures and leaks present a significant increase in methane emissions.

Dr. Ingraffea is a professor of engineering at Cornell University. He recently published a study showing that defects in oil and gas wells could in fact exacerbate greenhouse gas emissions -- and that modern wells are more likely than older wells to have these leaks and defects.

Between mounting studies showing methane leaks in fracking wells and this vast, newly confirmed methane cloud at the Four Corners, we're just starting to see the degree to which natural gas poses more of a climate threat than was previously understood. CO2 is just part of the story. We should proceed with extreme caution and skepticism.

Image credit: NASA/JPL-Caltech/University of Michigan