Tracking energy’s ‘fugitive emissions,’ from above
Scientists are trying to understand what’s released from the nation’s biggest energy producing regions.
The four-engine turbo-prop plane, built for hurricane research and surveillance, dips low over the pancake-flat plains that sweep from southeastern New Mexico across the Texas border. Huge irrigation circles are tattooed across the land in varying shades of brown and green. Then the well pads appear. From 1,000 feet in the air, they look like hundreds of sandboxes, connected by a maze of dirt roads.
“That’s a lot of wells,” says Joost de Gouw, a scientist with the National Oceanic and Atmospheric Administration Association and the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. As the lead researcher tracking the emissions over America’s energy hot spots, de Gouw has flown over oil and gas fields from North Dakota to Pennsylvania. Nowhere, however, has he seen a greater density of drilling operations than here in the Permian Basin, a 250-mile-wide-by-300-mile-long stretch of Texas and New Mexico — the nation’s most prolific oil field.
But De Gouw isn’t interested in the energy being produced here; he’s tracking the “fugitive emissions” leaking into the atmosphere. They include substances like methane, an odorless, colorless greenhouse gas far more potent than carbon dioxide, on a per-molecule basis, and volatile organic compounds, gases that produce a thick layer of pollution in the atmosphere linked to cancer and other health problems.
As part of NOAA’s Shale Oil and Natural Gas Nexus, or SONGNEX, project, de Gouw and 40 other researchers are trying to quantify those emissions and their effects on everything from the quality of the air we breathe to how much and how fast the planet will warm. Little attention was paid to methane emissions in the past, but with the current energy boom, the amount that’s being pulled from the earth and put into the air is rapidly increasing, and the need to understand emissions is becoming critical.
De Gouw earned his doctorate in atomic and molecular physics, but got into atmospheric science because he wanted to focus on something larger than the interactions of tiny particles no one could see. He has small wire-framed glasses and close-cropped sandy hair, and he speaks calmly, with a trace of a Dutch accent.
The inside of the plane is crammed with people and machinery. Scientists stare at monitors hooked up to air sensors outside the plane. The plane costs $5,000 an hour to operate, and today’s flight will last seven hours. It crisscrosses back and forth across the basin in a grid pattern, to better enable researchers to pinpoint the sources of the emissions.
Methane can come from a variety of sources, from a leaking pipeline to a landfill to a feedlot. So in order to find the source, the researchers must analyze the emission’s chemical signature: If the methane is accompanied by ethane and butane, it comes from oil and gas fields. If not, then it probably comes from somewhere else.
Getting these “top-down” readings from the air is crucial because it can provide a snapshot of an entire region. Previously, most measurements were taken at ground level, directly at a potential emissions source, which meant that scientists had to estimate the full scope of methane leaks and VOC pollution. The lack of concrete data meant anti-drilling proponents could cite certain studies that found high leak rates, while industry proponents could point to studies that found the opposite.
“There was no way to get to rational policy discussion,” says Drew Nelson, an expert on natural gas with the Environmental Defense Fund, which is sponsoring a series of studies to track down methane leaks and quantify them.
After more than 20 flights, de Gouw sees big differences between different basins. Over in Pennsylvania’s Marcellus shale formation, for instance, the researchers found a leak rate of less than 1 percent, compared to parts of Utah, where it was as high as 11 percent. The discrepancy is partly due to the formation’s composition: In Pennsylvania, it’s almost entirely “dry gas,” but out West, the gas is much wetter and requires a lot more processing before it’s ready for market. The liquid hydrocarbons are separated from the natural gas at the wellhead, and that creates a greater potential for leaks.
But de Gouw suspects that regulations — or the lack of them — also play a role. In Utah’s Uinta Basin, for instance, oil development was supposed to be a short-term project when it began back in the early 1980s. As a result, most pipelines were built aboveground, which is cheaper than burying them, but also leads to higher leak rates. Thirty years later, they’re still in use.
Ahead of us, flames erupt in the Guadalupe Mountains. Oil is almost always accompanied by natural gas, and it’s often not cost-effective for an oil company to build infrastructure to capture the natural gas released during the drilling. So most of the natural gas, along with other unwanted byproducts, is burned off, a process known as “flaring” that releases pollutants like benzene and VOCs into the atmosphere. De Gouw notes his data show that refiners in Utah are sending around 200,000 tons of VOCs into the air each year, double what producers have reported to the EPA.
Does de Gouw believe that methane leaks are cooking the planet faster than previously thought? The scientist won’t say. “I like to keep my opinions out of it,” he says. A moment later, the plane dips precipitously and de Gouw, unaffected by the stomach-churning turbulence, politely excuses himself. He turns toward where his computer sits at the back of the plane: “I’m going to go see what the data says.”
