New Aerial Methane Study Finds High Emissions from Oil and Gas Facilities

May 7, 2014
Lauren Whittenberg, (512) 691-3437,
Alison Omens, (202) 507-4843,

(WASHINGTON, D.C. – May 7, 2014) A new peer-reviewed study, led by scientists with the National Oceanic and Atmospheric Administration (NOAA) and the Cooperative Institute for Research in Environmental Sciences (CIRES) at UC-Boulder, reports much higher than estimated methane emissions in Colorado’s largest oil and gas region from associated equipment and operations. Accepted today to be published in American Geophysical Union’s Journal of Geophysical Research – Atmospheres, this study is the latest in a series of scientific reports offering substantial evidence that major reductions in methane emissions from this sector are urgently needed. The study also reports that emissions of benzene, a known carcinogen, are seven times higher than official estimates and emissions of smog-forming volatile organic compounds (VOCs) are twice as high as previously estimated.

The NOAA-CIRES study, part of an ongoing methane research effort coordinated by Environmental Defense Fund (EDF), comes on the heels of Colorado’s landmark regulation to limit oil and gas air pollution. Colorado is the first in the nation to directly target methane, which is commonly leaked or vented from oil and gas equipment and facilities. The new rules will curb nearly two hundred thousand tons of combined methane and VOCs annually.

“When it comes to air pollution from the oil and gas industry, Colorado is a state on the leading edge of science and regulation,” said Mark Brownstein, EDF’s associate vice president and chief counsel, US Climate & Energy. “The study underscores the importance of the steps that Colorado is taking to reduce total hydrocarbon pollution – both VOCs and methane – from oil and gas operations. I hope other states and the federal EPA are paying attention to the science and policy emerging in Colorado.”

Total methane emissions were estimated on two days in May 2012 based on methane mixing ratios in the air measured by a specially instrumented aircraft flown around the Denver-Julesburg Basin and on vertically resolved winds measured by two NOAA ground-based instruments. The portion of regional methane emissions attributed to all oil and gas activity was determined by subtracting an emission inventory of other methane sources. The study found that oil and gas operations in the basin emitted roughly 19.3 metric tonnes of methane emissions every hour, which the authors calculate as a leak rate of 4.1 percent (± 1.5) of total gas produced – an estimate almost three times higher than inventory estimates based on 2012 Environmental Protection Agency Greenhouse Gas Reporting Rule data.

These findings reinforce the fact that methane from the oil and gas sector is a problem requiring prompt action from both industry and policymakers. Methane, the main ingredient in natural gas, is a powerful and short-lived climate pollutant that accelerates the rate of climate change, which is contributing to more frequent and more intense extreme weather events among other serious impacts on public health and welfare. Over one-third of today’s human-caused global warming is caused by short-lived climate pollutants such as methane — and is expected to continue to do so in the absence of action, according to the Intergovernmental Panel on Climate Change (IPCC).

Almost universally, recent studies have shown methane leakage rates from this industry are higher than expected nationwide, undercutting the potential climate benefits of natural gas. America’s largest industrial source of methane emissions is the U.S. oil and gas industry. Targeting reductions here is critical for the U.S. to meet its climate goals. Further, the equipment used to capture methane often has the co-benefit of reducing other harmful pollution, including VOCs and toxic air pollutants like benzene. These technologies also reduce the waste of a vital national resource and frequently save producers money through the sale of captured methane.

A recent economic analysis by ICF showed that oil and gas companies can cost-effectively reduce methane emissions by 40 percent in the next five years using available technologies. The report also found that 90 percent of the methane reduction opportunities come from repairing and modifying existing infrastructure, where current EPA regulations only focus on new sources and a limited subset of all oil and gas activities.

For more information on the NOAA-CIRES study, read this blog by EDF Chief Scientist Steve Hamburg.

EDF’s Methane Research Series

In 2012, Environmental Defense Fund spearheaded its largest scientific project to date to advance the understanding of where and how much methane is lost across today’s U.S. natural gas supply chain. This collaborative series involves partnerships with nearly 100 universities, research institutions and oil and gas companies. It is divided into 16 distinct projects that will estimate methane emissions in a given area or from specific pieces of equipment. A range of sophisticated scientific techniques are being deployed across all projects. Insights from this effort are helping inform policies and opportunities to minimize methane emissions from the natural gas supply chain.

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