A massive amount of the greenhouse gas methane is being released into the atmosphere from underground leaks of natural gas, producing a major U.S. “hot spot” that was previously unknown, according to satellite data released by scientists at NASA and the University of Michigan on Thursday.
The 2,500 square mile hot spot — located near the Four Corners border of Arizona, Colorado, New Mexico and Utah — is spewing methane, a powerful greenhouse gas that is 20 times more effective at causing global warming than carbon dioxide. The methane is likely not from fracking, NASA said, since the data analyzed is from 2003 to 2008, before the fracking boom. Instead, the scientists hypothesize that the leaks are coming from coalbed methane extraction, a process of getting natural gas from underground coal beds.
The discovery is important not only because it’s the largest concentrated spot of methane emissions in the United States, but also because it leaves questions as to whether there are other big hot spots that we’re unaware of. The methane coming from this hotspot is 3.5 times greater than what’s shown in the European Union’s popular Emissions Database for Global Atmospheric Research. This is also not the first time methane emissions have been underestimated, either — a study published in the journal Science this past February charged the U.S. Environmental Protection Agency of underestimating the amount of methane in the atmosphere by 50 percent, claiming the agency had not accurately been taking into account how much natural gas has been leaking from the production chain.
The hotspot released an average of 590,000 tons of methane emissions into the atmosphere every year from 2003 to 2009. That’s a staggering amount — 590,000 tons of methane emissions is equal to almost 15 million tons of carbon dioxide, or the climate equivalent of adding 3.1 million cars to the road every year.
Compared to other sources of methane emissions, this is also pretty big. If the EPA’s calculations are to be believed, the amount of methane coming out of the hotspot could be more than the methane leaked annually from natural gas pipelines. The EPA says natural gas pipelines released 13 million metric tons of carbon dioxide equivalent in 2012. But some scientists say methane could be much greater, spewing from pipelines at a rate of up to 21 million metric tons of carbon equivalent every year.
Still, other sources of methane emissions in the United States contribute significantly more to climate change than the Four Corners hotspot. Yearly methane emissions from U.S. agriculture, land use, forestry, landfills, and energy production in general are all remarkably higher than what’s coming from the 2,500 square mile chunk of land in the southwest.
According to the EPA data from 2012, methane from agriculture operations produced 201 million tons of carbon dioxide equivalent; methane from waste and landfills made 117 million tons of CO2 equivalent; and methane from land use and forestry created 15 million tons of CO2 equivalent. Fossil fuel energy in general produced a whopping 229 million tons of CO2 equivalent in 2012, according to EPA.
CREDIT: Dylan Petrohilos
The methane from the Four Corners hotspot does definitely beat out at least one source, though — the methane leaks from the ocean floor off the United States’ eastern seaboard. Scientists recently found 570 separate plumes of methane bubbles rising from the floor from the Atlantic ocean, emitting what they calculated to be 2,250 tons of CO2 equivalent per year. That’s way less than what’s coming from the midwestern hotspot, but researchers also estimate there could around 30,000 more similar ocean floor methane leaks all over the world. Still, if those leaks are all similar to the ones on the eastern seaboard, that would still only add up to 119,250 added tons of CO2 equivalent every year. In terms of methane, we seem to have bigger fish to fry.
The one positive thing about these bigger industry fish is that, unlike the hotspot, we know a lot about why they produce so much methane, and have ideas on how to potentially curb them. For example, the United Nations calculates that methane emissions from livestock can be cut by 30 percent just by adopting better farming practices. The Obama administration’s Climate Action Plan has a whole strategy to cut methane emissions, which includes proposed EPA regulations to reduce methane from landfills, standards for oil and gas operators to reduce venting and flaring, and partnerships with the dairy industry to voluntarily reduce methane emissions from cows.