EPA has Underestimated Methane Emissions, Study Says

The EPA has seriously underestimated the emissions of the powerful greenhouse gas, methane, particularly from oil and gas activity (five times) and from cattle and livestock operations (two times), according to a new report published in the PNAS.

2 minute read

December 6, 2013, 6:00 AM PST

By Irvin Dawid


The paper, "Anthropogenic emissions of methane in the United States", written by 15 climate scientists was published Nov. 25 in the Proceedings of the National Academy of Sciences (PNAS). "Its conclusions are sharply at odds with the two most comprehensive estimates of methane emissions, by the Environmental Protection Agency (EPA) and an alliance of the Netherlands and the European Commission," writes Michael Wines.

According to the EPA's "Overview of Greenhouse Gases" webpage on methane emissions:

Methane (CH4) is the second most prevalent greenhouse gas emitted in the United States from human activities [after carbon dioxide which accounts for 84%]. In 2011, CH4 accounted for about 9% of all U.S. greenhouse gas emissions from human activities... Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 over a 100-year period. [See 'overview' for the other three gases]

The most serious differences occurred where oil and gas drilling was concentrated. "Methane discharges in Texas and Oklahoma were 2.7 times greater than conventional estimates. Emissions from oil and gas activity alone could be five times greater than the prevailing estimate, the report said."

The E.P.A. has stated that all emissions of methane, from both man-made and natural sources, have been slowly but steadily declining since the mid-1990s. In April, the agency reduced its estimate of methane discharges from 1990 through 2010 by 8 to 12 percent, largely citing sharp decreases in discharges from gas production and transmission, landfills and coal mines.

The new analysis calls that reduction into question, saying that two sources of methane emissions in particular — from oil and gas production and from cattle and other livestock — appear to have been markedly larger than the E.P.A. estimated during 2007 and 2008.

In September, Michael Wine had written about a University of Texas-Austin study, also published in PNAS, but unlike this recent study, it was not based on estimates but actual methane released from fracking operations. It concluded that "it was probably less than the Environmental Protection Agency estimated in 2011." 

"This new work clearly points to the importance of the E.P.A. updating how it tracks this important emission, and also bolsters arguments for the Obama administration to move forward faster with its proposed standard [PDF] for cutting leaks and emissions from oil and gas operations," writes Andrew Revkin in The New York Times DoT Earth blog.

Monday, November 25, 2013 in The New York Times

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Blue and silver Amtrak train at small station.

Amtrak Rolls Out New Orleans to Alabama “Mardi Gras” Train

The new service will operate morning and evening departures between Mobile and New Orleans.

July 3 - New Orleans City Business

Large spinning swing ride at Chicago's Navy Pier.

The Subversive Car-Free Guide to Trump's Great American Road Trip

Car-free ways to access Chicagoland’s best tourist attractions.

July 3 - Streetsblog Chicago

Aerial view of downtown San Antonio, Texas at night with rotating Tower of the Americas in foreground.

San Antonio and Austin are Fusing Into one Massive Megaregion

The region spanning the two central Texas cities is growing fast, posing challenges for local infrastructure and water supplies.

July 3 - Governing