Scientists have found that Colorado’s Front Range oil and gas boom has been emitting three times more methane than previously believed — 19.3 tons an hour — a climate-change problem that state officials hope new rules will address.
The scientists also measured industry emissions of cancer-causing benzene and smog-forming volatile organic compounds at levels up to seven times higher than government agencies have estimated.
Their study — done at the National Oceanic and Atmospheric Administration’s Cooperative Institute for Research in Environmental Sciences and partly supported by the Environmental Defense Fund — is based on data gathered in 2012 from aircraft flying over the drilling zones north of Denver.
It is heading for publication amid White House warnings that climate change increasingly affects Americans and calls by United Nations-backed Intergovernmental Panel on Climate Change for a faster shift off fossil fuel to clean energy to avoid dangerous disruptions.
Colorado health officials in February adopted stricter rules for the oil and gas industry to control air pollution. Gov. John Hickenlooper has called for zero emissions of methane, which the Environmental Protection Agency has determined to be 20 times more potent than carbon dioxide in trapping heat — causing climate change.
The oil and gas industry is the main source of methane in the United States. Industrial livestock operations and landfills also emit methane, and the CIRES researchers said they accounted for those numbers and subtracted.
“We’re trying to provide independent information on air pollution to help decision-makers and industry minimize their impacts,” lead scientist Gabrielle Petron said. “If the energy industry keeps expanding operations on the Front Range, we need to know we will have a good handling of the emissions.”
Industry representatives at the Colorado Oil and Gas Association declined to comment on the study, but it released a statement that said, “Colorado is a model for the rest of the nation regarding not just air regulations, but for the state’s oil and gas regulations as a whole.”
Colorado Department of Public Health and Environment officials said new state rules will reduce oil and gas industry methane pollution by 113,000 tons a year. They know about the study but haven’t thoroughly reviewed it, said Garry Kaufman, deputy director of CDPHE’s air pollution control division.
“We recognize that methane emissions are an issue,” Kaufman said in an e-mailed response to queries. “These new rules are just now going into effect, so the measurements in the study were gathered before they could have had any impact.”
For years, CDPHE and EPA officials have estimated air pollution primarily by measuring ground-level sources. State agencies didn’t begin monitoring methane until 2012.
The new study marks one of the first efforts to investigate pollution in the atmosphere above ground level. Petron led atmospheric scientists who used a small airplane in May 2012 to test air. Previously, Petron and colleagues have gathered air-pollution data using vehicles packed with instruments and a 985-foot tall tower east of Erie.
Using the airplane, they found that oil and gas operations in Weld County emitted 19.3 tons of methane per hour — about 75 percent of total methane emissions in the area. That’s about three times higher than an hourly average based on the EPA’s annual estimates, which are drawn from industry-reported emissions.
Petron and her team also measured benzene emissions from oil and gas operations at about 380 pounds per hour — nearly eight times higher than a CDPHE estimate of 50 pounds per hour.
And they measured industry volatile organic compound emissions, which contribute to ozone pollution, at 25 tons per hour. That’s nearly double the state estimate of 13.1 tons. For years, Colorado’s Front Range has failed to meet federal ozone air quality standards.
More aerial testing is planned this summer in Colorado. The Environmental Defense Fund plans to support a similar study in Texas, EDF chief scientist Steven Hamburg said.
“These data show how very important Colorado’s regulations are in ensuring we address climate change as effectively and quickly as possible,” Hamburg said. “We need to minimize methane associated with production of oil and gas, and the amount of carbon dioxide coming out of smokestacks and tailpipes. That combination will be powerful in reducing the rate of warming.”
Bruce Finley: 303-954-1700, bfinley@denverpost.com or twitter.com/finleybruce
Updated May 9, 2014 at 1:20 p.m.: This story incorrectly characterized the Colorado Oil & Gas Association’s response to a study about air pollution. Although the organization declined to comment on the study, it released a statement that said, “Colorado is a model for the rest of the nation regarding not just air regulations, but for the state’s oil and gas regulations as a whole.”
