Case Studies: The Impacts of Extracting and Burning Natural Gas

Numerous studies have showed that the processes of extracting and burning natural gas, including fracking, have grave environmental impacts. Here are a few of them.

Shale Fracking in Texas

Lynn Buehring wears a breathing mask outside her home in Karnes County. She lives with her husband in the middle of three different hydrofracking wells that have been flaring since 2011. She is suffering from severe reactions to the chemicals and Hydrogen Sulfide (H2S) gas released from the wells. Her entire life has been turned upside down. A retirement place on a quiet country road has now become a nightmare. She has to wear a respirator whenever the winds blow in her direction. She is suing Marathon Oil for relief.

© Les Stone / Greenpeace

New Studies Find Massive Methane Leakage From Fracking

New studies from the Front Range area of Colorado, Utah, and Marcellus region of Pennsylvania have found VOC and methane leakage from fracking wells that far exceed EPA’s predictions. These studies measure methane levels from the air, which can capture emission data from fracking plays that can have thousands of wells concentrated in one area. Previous studies have used ground-based measurements of a handful of wells, which can miss super-emitting sources in the gas fields.


Scientists have found that an area of Colorado that has seen a huge boom in oil and gas drilling has been emitting three times more methane than previously believed — 19.3 tons an hour. The area is called the Front Range, and is home to one of the biggest fracking booms in the US.

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. These emissions have been shown to be dangerous to people near gas development, causing health problems in adults and linked to birth defects.

Acknowledging the serious problem posed by air pollution from fracking, Colorado’s Governor John Hickenlooper proposed a set of new air regulations on fracking, the first in the nation. Various shale industry companies approved the regulations, which signals that the industry is aware that air emissions from fracking are dangerous and undeniable. Because of the fracking boom, the ozone levels in the Front Range of Colorado are worse than those in Los Angeles.


A study published in March of 2014 in the Proceedings of the National Academy of Sciences found that drilling operations in Pennsylvania emitted 100 to 1,000 times more methane than the Environmental Protection Agency previously estimated. The study took air measurements from 7 well pads, and observed a leakage of 34 grams of methane per second, on average, much higher than the EPA-estimated 0.04 grams to 0.30 grams of methane per second.

The study, conducted by Cornell University, found methane emission rates from the drilling process were up to 1000 times EPA estimates.


A team of researchers from NOAA in Utah’s Uintah basin determined that methane emissions from the oil and natural gas fields in totaled about 55,000 kg (more than 120,000 lbs) an hour. That emission rate is about 6 to 12 percent of the average hourly natural gas production in Uintah County during the month of February. Overall they found a leakage rate of 60 tons per hour for the day they measured.

A recent industry funded study out of the University of Texas estimated that methane’s leak rate, nationally, is around 1.5 percent of production, but studies like the one done over the Uintah basin call those estimations into question.

Methane Emissions From End Use

The infrastructure required to transport and use gas has become a major concern as new studies have found huge methane leakage rates. For example, new methane surveys in major cities have found dangerously, sometimes explosively high levels of methane leaking from aging city infrastructure. A recent deadly explosion in New York City was due to exactly these kinds of methane leaks.

Pipeline Leakage

Beyond the methane leaks from drilling and venting associated with existing and abandoned wells, more methane is lost every day in processing, handling and transporting gas to its ultimate point of consumption. Pipeline losses occur in a more than 2-million-mile system that stretches from the production fields to residential customers. This gas transportation system has three main parts:

1.) gathering lines in production fields which are largely unregulated, and in many systems, unknown and unmapped (about 240,000 miles estimated);

2.) natural gas transmission pipelines to processing and storage locations (278,269 miles); and

3.) distribution lines to residential and business customers (about 1.8 million miles).

Leakage of methane from pipelines – a problem throughout the world – has been reported and studied for years. New Scientist noted in September 1990, that natural gas pipeline mains in Great Britain leaked so much methane that the leaks there contributed more to global warming than did the burned gas. As of 2006 the U.S. natural gas industry operated over 38,000 miles of natural gas pipelines that were made of cast iron, the most leak-prone type of gas piping. In 2012, a U.S. GAO study on thousands of miles of “gathering lines” that collect oil and gas from production sites revealed that these lines are not regulated by the federal government, meaning they are not regularly inspected for leaks or corrosion.

An incident report of January 2013 filed for a Questar Company natural gas pipeline operating in rural Duchesne County, Utah near the town of Roosevelt, indicated that a relief valve on the line was opened and vented gas for approximately 3 hours and 55 minutes, resulting in a “DOT reportable incident” of some 3 million standard cubic feet or more of unintentionally released gas. This report also indicated that the release occurred in “a very rural area,” and that there were “no off-site impacts reported.”  These are the kinds of methane releases that are likely occurring throughout the oil and gas patch nationwide.

Urban Distribution Pipes: Markey Report

There is a widespread national problem with gas leaks and pipeline failures in urban gas distribution systems. According to a report released by U.S. Senator Edward Markey (D-MA), gas distribution companies in 2011 reported releasing 69 billion cubic feet of natural gas to the atmosphere, almost enough to meet the state of Maine’s gas needs for a year and equal to the annual carbon dioxide emissions of about six million automobiles. Gas companies, however, are slow to replace bad pipe. In 2012 gas companies replaced just 3 percent of their distribution mains made of cast iron or bare steel. Leaky gas pipes nationwide presently span about 91,000 miles across 46 states. Nationally, consumers paid at least $20 billion from 2000-2011 for gas that was unaccounted for and never used. Observes the Markey report:

Natural gas has been touted as a cleaner alternative to coal for producing electricity, but its environmental benefits cannot be fully realized so long as distribution pipelines are leaking such enormous quantities of gas, which is primarily comprised of methane, a greenhouse gas that is at least 21 times more potent than CO-2. Americans also remain at risk from gas explosions and other safety hazards caused by leaky natural gas pipelines. From 2002 to 2012, almost 800 significant incidents on gas distribution pipelines, including several hundred explosions, killed 116 people, injured 465 others, and caused more than $800 million in property damage.

In 2013, researchers conducted a 1500-mile street-by-street survey in Washington, DC, finding nearly 6,000 leaks from the city’s aging pipe system, including 12 locations where methane had collected to explosive levels (50,000 to 500,000 ppm). A similar report conducted in Boston found almost 3,400 pipeline leaks across 785 miles. The Pipeline and Hazardous Materials Safety Administration (PHMSA), a regulatory agency within the Department of Transportation, is responsible for tracking pipeline safety and emissions.   According to analysis of 2011 industry data reported to PHMSA, the average lost and unaccounted for percentage of gas among 174 companies with natural gas distribution systems of 1000 pipeline miles or more was 1.6%.

Together with studies of gas production fields that have found methane emissions many times greater than estimated, these studies paint a picture of a gas infrastructure that contributes significant amounts of greenhouse gas to the atmosphere.

Purposeful Emissions: Venting and Flaring

In addition to accidental, or fugitive emissions, there are a significant amount of purposeful emissions from oil and gas production in the form of venting and flaring.

Venting involves releasing gas directly into the atmosphere during normal operational extraction and handling. In the past, methane gas was considered a waste product of oil drilling, and was vented directly into the atmosphere in huge quantities. Between 1973 and 1989, an annual average of more than 130 billion cubic feet of natural gas was flared or vented during production. In addition, thousands of oil storage tanks also emit plumes of methane and other gases. In 2008, according to EPA’s estimates, the amount of natural gas vented and flared on onshore federal oil and gas leases totaled around 126 billion cubic feet (Bcf) of gas.

In some of today’s oil fields, like the Bakken in North Dakota, gas is still an unwanted byproduct that is vented rather than stored. This usually occurs in oil extraction areas that are not adjacent to gas pipelines.

Gas is also commonly flared or burned off. Flaring emits CO2 as a combustion by-product, while venting releases methane and other chemicals. In wells where oil and gas are co-produced, the “associated gas” is usually vented or flared off continuously. This flaring does not burn 100% of the gas, leading to VOC and methane pollution. In fact scientists are not sure how much residual methane and air contaminants escape from flares unburned.

In September 2011, the New York Times reported that every day, more than 100 million cubic feet of natural gas was being flared in the Bakken shale region. That flared gas also accounts for at least two million tons of carbon dioxide released into the atmosphere every year, roughly equivalent to the emissions of a medium-size coal-fired power plant.  According to the U.S. Energy Information Administration (EIA), as of 2011 more than 35 per cent of North Dakota’s natural gas production was burnt off in flares. In addition, there is very little oversight of venting and flaring in many U.S. production regions, and current industry reporting is not always reliable.

Other hydrocarbons and compounds that are present in vented and flared gas – such as volatile organic compounds – can harm air quality by increasing ground-level ozone levels and contributing to regional haze. For example, VOC pollution from the oil and gas industry has been a growing concern in Colorado, where Governor John Hickelooper and the oil and gas industry were forced to propose new regulations, because of high levels of air pollution from fracking. Ozone pollution from fracking in Colorado has become so bad that the air quality of the sparsely populate Front Range was as bad as Los Angeles.

Oilfield accidents, broken valves and gauges, and sudden pressure surges can also result in irregular releases.

Black Carbon

One associated greenhouse problem with flares is that they are also a global source of something called “black carbon”– a kind of particulate matter that also figures into the global warming calculus, though their role is not precisely understood. The action of black carbon is, like methane, a “short lived climate forcer.” Some scientists believe black carbon’s total effect in the atmosphere is likely to be second only to CO2. In 2011, the Arctic Council noted that gas flaring is a source of black carbon that “requires special attention,” and in March 2012, EPA reported to Congress that black carbon emissions from flaring were of “particular concern.” Comprehensive estimates of black carbon emissions from the natural gas industry do not exist.

LNG Exports

With the boom in U.S. shale gas production as one of the key drivers, the U.S. is gearing up to become a major exporter of natural gas. Many see the U.S., with its projected plentiful supplies of gas and a pipeline network that can move the gas to seaside locations for export, as well positioned to capitalize on the boom. Natural gas can be liquefied and compressed to liquified natural gas (LNG) for long distance transport to overseas markets by way of specially-equipped tankers. At the export sites, the gas must first be liquefied at specialized facilities, then shipped in tankers that store the gas at 260 degrees below zero. A number of companies are now seeking approval to export LNG from about 24 locations in the U.S. According to the Congressional Research Service, there have been 31 applications for U.S. LNG export permits. This potential export capacity represents nearly 50 percent of current U.S. production. Eight of the projects involve construction of liquefaction facilities at costs ranging from $6 billion to $10 billion each. New LNG export terminals would cost in the range of $20 billion each. As of September 2013, most of the projects have already received approval. Four others, with some limitation – Sabine Pass, Freeport, Lake Charles, and Dominion Cove Point – have received DOE approval to export to non-free-trade countries.

Industry analysts forecast that demand for LNG will more than double from about 240 million tons in 2012 to 550 million tons annually by 2030. Major oil and gas companies, including Chevron, Exxon Mobil, Royal Dutch Shell and Total, are planning up to $400 billion in LNG investments around the world. ExxonMobil, for one, has been among American companies pushing DOE to speed up its approval of applications to export natural gas. ExxonMobil is also seeking a Canadian LNG export license for British Columbia. The American Petroleum Institute (API) has also urged DOE to speed up the pace of approving LNG export facilities. “There is a global race to build this infrastructure and secure a competitive position in the international market,” Erik Milito, director of the upstream sector for API, said in an October 2013 statement.

Cove Point, Maryland

In September 2013, the Department of Energy approved permits for a fourth LNG export facility at Cove Point, Maryland.  Situated on Chesapeake Bay, the Cove Point facility was initially opened in 1978 as an LNG import site. Dominion Energy wants to reengineer the plant to converted gas into LNG for export.  Opponents of the plant have raised concerns about related pipeline construction, increased demand for gas extracted by fracking in the region. A number of other U.S. LNG terminals – originally built to receive LNG imports – are also in the queue for permits to be modified for exporting LNG.

In the wake of the crisis in Ukraine, members of both parties and the Obama Administration supported expediting the approval of LNG export facilities as a national security priority.  On March 24, 2014, the Department of Energy gave preliminary approval to the seventh LNG export facility – the first on the west coast – the Jordan Cove terminal in Coos Bay, Oregon.

Among those on Capitol Hill supporting gas exports and calling on the Obama administration for faster approval of pending applications is Senator Lisa Murkowski, the top Republican on the Senate energy committee, who has stated, “the United States has a narrowing window of opportunity to join the global gas trade.” Other lead proponents include Senate Energy and Natural Resources Committee chair Mary Landrieu (D-LA) and Senator Mark Udall (D-CO), who introduced a bill (S. 2083) that would fast track LNG exports by automatically deeming LNG exports to WTO member countries in the public interest.


Rising methane emissions are also part of the LNG export equation, since the use of liquefied natural gas adds three additional stages to the natural gas life-cycle – liquefaction (where gas is cooled and pressurized), offloading and regasification (where LNG tankers offload their cargo) and transmission. In May 2013, offering congressional testimony, James Bradbury of the World Resources Institute explained: “The process of liquefaction, transport, and regasification of LNG is highly emissions-intensive, increasing by 15 percent the total life cycle GHG emissions associated with exported U.S. natural gas, compared to natural gas that is produced and consumed domestically. These added upstream emissions also significantly reduce the relative advantage that natural gas would have over higher-emitting fuels, like coal and oil.” In 2014, the Environmental Integrity Project estimated that of the 21 new LNG export terminals projected for development by the Federal Energy Regulatory Commission, 9 have obtained or applied for Clean Air Act permits that add up to 29 million tons of greenhouse gas emission per year – more than 3 large coal plants combined.

DOE Report finds LNG worse than coal

A recent DOE study of LNG exports facilities found that liquification and shipment of methane would be detrimental to the climate. The report found that benefits of cleaner, more efficient combustion of natural gas are largely offset by methane leakage in U.S. production and pipelines and by methane leaks and energy used in the process of liquefying and transporting the LNG. In the case of shipping LNG from the U.S. gulf coast to Shanghai, the greenhouse gas benefits could in some cases be completely offset by those factors when measured over a 20-year period, the report says.

U.S. exports of LNG to China could end up being worse from a greenhouse gas perspective than if China simply built a new power plant and burned its own coal supplies


  • Working Group I, “Contribution to the IPCC Fifth Assessment Report, Climate Change 2013: The Physical Science Basis,” Final Draft Underlying Scientific, Technical Assessment, September 26. 2013.
  • Shindell et al. estimate 20-year GWP for methane, including aerosol responses, to be 86 to 105.  Drew T. Shindell et al., “Improved Attribution of Climate Forcing to Emissions,” Science, 30 October 2009, Vol. 326, pp 716-718.
  • U.S. Government Accountability Office (GAO), Pipeline Safety: Collecting Data and Sharing Information on Federally Unregulated Gathering Pipelines Could Help Enhance Safety, March 22, 2012, GAO #12-388, 41pp.
  • “Questar Natural Gas Leaked 4 Hours – 3 Million Cu Ft Lost to Global Warming – ‘Just a Rural Area’,”Arlington TX Barnett Shale Blogger, January 15, 2013.
  • “America Pays for Gas Leaks: Natural Gas Pipeline Leaks Cost Consumers Billions,” A Report Prepared for U. S. Senator Edward J. Markey (D-MA), U.S. Senate, August 1, 2013.
  • “America Pays for Gas Leaks: Natural Gas Pipeline Leaks Cost Consumers Billions,” A Report Prepared for U. S. Senator Edward J. Markey (D-MA), U.S. Senate, August 1, 2013.
  •; Note that data regarding distribution pipes does not include data for gas transmissions or gathering. See “Significant Pipeline Incidents” data, PHMSA. Available at:
  • Robert B. Jackson et al., “Natural Gas Pipeline Leaks Across Washington, DC,” Environmental Science & Technology, January 16, 2014.  Available at
  • N.G. Phillips, et al., “Mapping urban pipeline leaks: Methane leaks across Boston,” Environ. Pollut. 2013, 173, 1-4. See for more information.
  • Jack Doyle, Crude Awakening: The Oil Mess in America, Friends of the Earth, Washington, D.C. , 1994, p. 201.
  • U.S. General Accountability Office (GAO), Federal Oil And Gas Leases: Opportunities Exist to Capture Vented and Flared Natural Gas, Which Would Increase Royalty Payments and Reduce Greenhouse Gases, Report No. GAO-11-34, November 29, 2010.
  • Clifford Krauss, “In North Dakota, Flames of Wasted Natural Gas Light the Prairie,”New York Times, September 26, 2011.
  • Julia Sklar, “Gas Flares from Bakken Fracking Are Visible from Space,” New Scientist, January 28, 2013.
  • US EPA (2012).Report to Congress on Black Carbon.EPA-450/R-12-001, Research Triangle Park, NC, United States Environmental Protection Agency.
  • Arctic Council (2011). Arctic Council Task Force on Short-Lived Climate Forcers Progress Report and Recommendations for Ministers, Nuuk Greenland. Arctic Council Task Force on Short-Lived Climate Forcers.
  • M. Z. Jacobson, “Short-term Effects of Controlling Fossil-fuel Soot, Biofuel Soot and Gases, and Methane on Climate, Arctic Ice, and Air Pollution Health,”.J. Geophys. Res. 115, 2010.
  • See
  • Michael Ratner, Paul W. Parfomak, Ian F. Fergusson, and Linda Luther, “U.S. Natural Gas Exports: New Opportunities, Uncertain Outcomes,” Congresional Research Service, Washington, DC, September 17, 2013.
  • Peter Galuszka, “U.S. Gears Up to Be a Prime Gas Exporter,” New York Times, September 30, 2013.
  • U.S. Department of Energy, “Energy Department Authorizes Dominion’s Proposed Cove Point Facility to Export Liquefied Natural Gas,”,  September 11, 2013
  • Chesapeake Climate Action Network,
  • U.S. Senate Committee on Energy & Natural Resources, “Murkowski Comments on DOE Approval of Dominion Cove Point LNG Export License,”, September 11 2013.
  • Testimony of James Bradbury, Senior Associate, Climate and Energy Program, World Resources Institute, Before the U.S. House of Representatives Energy and Commerce Subcommittee on Energy and Power, Public Hearing: “U.S. Energy Abundance: Exports and the Changing Global Energy Landscape,” May 7, 2013.
  • Environmental Integrity Project, “Gas Rush: Increasing Greenhouse Emissions from New Oil, Gas, and Chemical Plants,” December 5, 2013. Available at:

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