On a methane mystery tour in the Four Corners region

Scientists, planes and instruments descend on San Juan Basin to find roots of the massive greenhouse gas hotspot.


When you get a bunch of scientists together on a Friday morning to talk about hyperspectral imaging, isotopes and teragrams, you probably don’t expect a big turnout. Yet on April 17, some 200 people crowded a classroom at San Juan College in Farmington, New Mexico, to hear scientists do just that. Okay, the crowds were not there for the technical stuff, per se, but to hear about the current effort to unravel the mysteries of the now notorious Four Corners Methane Hotspot, a massive concentration of potent greenhouse gas detected by a satellite between 2003 and 2009. The satellite eventually stopped functioning, but the hotspot is presumably still there. The study detailing the satellite's findings was released last year.

Image showing hotspot of methane anomalies, shown in orange and red, centered over the Four Corners region from 2003 to 2009, when a satellite-based methane-measuring instrument was operational. The April study will focus on verifying the hotspot and determining the methane sources producing the exceptionally elevated methane concentrations.

The crowd, a mix of industry and agency folks, environmentalists and regular citizens, was a bit anxious. Even the elevated concentrations in the hot spot zone pose no threat to human health, but methane is far more potent as a greenhouse gas than carbon dioxide. Findings from this spring's investigation into the roots of the hotspot have the potential to inspire strict regulations on methane emissions from the fossil fuel extraction industries, the main driver of the region’s economy.

Ever since the satellite findings were released last year, regional environmentalists have been frustrated at what they see as the media’s refusal to pin the blame for the hotspot on the elephant in the room: The oil and gas industry. After all, the San Juan Basin is one of the most productive coalbed methane fields in the nation, teeming with a variety of pipelines, compressors and other machinery, some of which knowingly emit methane along with others that have vast potential for fugitive leaks. Yet after the hotspot was made public, some media accounts attributed it to everything but oil and gas drilling, from coal mining to coal burning power plants. The four large mines in or near the basin are significant contributors, power plants not so much: The San Juan Generating Station, for example, spews 31,000 metric tons of CO2 equivalent of methane each year, while its mine emits more than 800,000 tons of CO2e.

The frustration re-emerged when I tweeted from the forum that the scientists were here to tackle the “mystery” of the hot spot. Erik Schlenker-Goodrich, Director of the Western Environmental Law Center, quickly retorted, also via Twitter: “Confused by framing of hotspot cause as ‘mystery.’” There's no mystery, he said, noting that the oil and gas industry’s own emissions inventory reporting show that it contributes 90 percent of the methane in the San Juan Basin relative to other sources, such as coal mines. Framing it as a mystery was an excuse for inaction, he added.

But the hotspot, which shows up in the satellite imagery as a wound of yellow and red in a sea of blue pixels, is “not a map of emissions,” noted Eric Kort of the University of Michigan, “it’s a map of concentrations.” Clearly, you have to have high emissions to have such concentrations, but there’s more going on here than just inventoried emissions. Other high emission zones, such as the oil- and gas- and cattle-rich Weld County in northeastern Colorado or the Permian Basin in Texas and southern New Mexico don’t have huge anomalies (perhaps due to topography and wind patterns). And the San Juan Basin’s official emission inventories don’t get close to accounting for all the methane in the atmosphere. So there must be sources of greenhouse gases that are unaccounted for — a mystery.

Industry members, meanwhile, want to make sure that the study looks beyond oil and gas infrastructure, to other potential sources like coal mines, landfills, feedlots or, especially, known coalbed outcrops along the rim of the basin, where methane simply seeps into the air unbidden (look for more on this phenomenon in an upcoming HCN story). Oil and gas industry groups, understandably nervous given pending methane emission regulations, have tried to deflect blame from their operations, and redirect it toward the seeps and large coal mines in the basin. They argue that since methane, or natural gas, is their cash crop, it is in their interest to stop leaks and capture emissions — letting methane float off into the air is akin to letting money blow off in the breeze.

A forum attendee checks out one of the vans that will be cruising the backroads of the San Juan Basin in search of emitters of methane and other substances.
Jonathan Thompson
Kort, young, lanky and sporting a man-bun and trimmed beard, was the principal speaker at the forum. He outlined the multi-level, multi-scale investigation that he and his colleagues from NASA, NOAA and the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder would be engaged in during the coming weeks. They have already begun flying NOAA’s Twin Otter plane over the region in circles, squares and grid patterns in order to find methane plumes, that can then be pinpointed using ground-based mobile instruments. A NOAA P3 plane will also take to the San Juan Basin skies for a couple of flights, and planes from NASA’s jet propulsion laboratory will spend a week in the area, taking detailed hyperspectral images. A Japanese satellite will even focus on the region. And on the ground, scientists are driving the extensive web of backroads in specially-equipped vans, looking for spikes in methane concentrations as well as other emissions.

“It’s not model dependent,” says Kort, “it relies totally on measurements.” With a steady demeanor, Kort reassured the audience that he and his colleagues are here to use science to get to the bottom of things, and that they aren’t guided by any foregone conclusions. And science takes time: It could be a year or more before the data is analyzed and conclusions are reached. In the meantime, the precise causes of the methane hotspot will remain a mystery. Of sorts.

Jonathan Thompson is a senior editor at High Country News.

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