Energy Exchange

More To Come On Methane…

By Steven Hamburg / Published: December 6, 2012

Concerns around the impacts of methane emissions have reemerged in headlines, with the release of a methane leakage study about Boston. Published in the journal of Environmental Pollution a couple weeks ago, researchers from Boston University and Duke University measured atmospheric methane concentrations leaking from natural gas pipelines in Boston many of which are over a hundred years old. Another report issued last week by researchers at the Massachusetts Institute of Technology (published in Environmental Research Letters) looked at the impact of shale gas production on greenhouse gas emissions.

When talking about harmful greenhouse gases, carbon dioxide (CO2) usually gets most of the attention. Yet methane, the main ingredient in natural gas, is a short-lived greenhouse gas many times more potent than CO2 – or around 72 times more potent over a 20-year time frame. Stakes are high for the scientific community to fully understand the implications of methane leakage rates. These reports help elevate the issue that methane leakage matters to the climate and air quality, but this is only part of the story.

Methane is potentially leaking from the entire natural gas supply chain — from wells, pipelines and storage facilities — and no one knows precisely how much is leaking and where the leaks are stemming from. Some reports estimate the total methane leakage rate occurring during natural gas production, transmission and distribution to range anywhere from 1 to 7.9 percent. At the same time, the data that the Environmental Protection Agency (EPA) and everyone else rely on were collected 20 or more years ago.

A challenge for understanding the distribution of methane concentration data in Boston is that no one knows how to interpret the data yet. Maps of methane concentrations in the urban environment can be spurious. They may look scary, but are they? This and many other tough scientific questions still need to be answered, we are very early in the process of understanding how much methane is leaking and from where. The scientific community at large, including EDF and the authors of the Boston study, are committed to collecting the data necessary to addressing these concerns and to understanding the true climate impact of methane emissions.

EDF is working with leading academic researchers and industry leaders to conduct scientifically rigorous measurements of quantitative emissions across the natural gas supply chain from well to the end user. We are developing the methodologies where necessary to move past a ‘he said, she said’ conversation to one focused on data characterizing leak rates. The critical next step for us in using the increasingly robust data gathered from new innovative technologies is to precipitate a clear enough understanding of where the leaks are in the supply chain to catalyze a constructive conversation about what new policies and industry practices will be required to minimize methane leakage.

The first EDF fugitive methane report, focused on field measurements made at natural gas production sites, will be completed early next year under the leadership of the University of Texas Austin. EDF and our partners are using a diverse array of measurement techniques to characterize leak rates. We are also working to make basin-wide measurements within areas of natural gas production. Over the course of 2013 and early 2014, studies of emissions at other key components in the supply chain, including the local distribution system, will be completed and the data and conclusions released to the public.

EDF is actively campaigning to ensure that fugitive methane emissions from the natural gas industry are less than 1 percent of production in order to ensure that the climate benefits of natural gas are maximized. We see development of innovative, cost effective and accurate methane detection technologies and procedures as a necessary part of minimizing leak rates. Our view is that minimizing methane leakage is an important enough issue that we need to take the time to establish a scientific understanding of the underlying issues and by doing so defining effective well-targeted actions.

Also posted in Climate, Natural Gas / Read 1 Response

Loose Use Of Facts Undermines Credibility Of White’s OpEd

By Jim Marston / Published: November 7, 2012

This commentary was originally posted on the EDF Texas Clean Air Matters Blog.

An erroneous and misleading opinion piece by Kathleen Hartnett White with the Texas Public Policy Foundation, ran in Sunday’s The Austin American-Statesman. In the article, White misrepresents several important details from a 4-year old EDF report that was prepared by Dr. Al Armendariz, a former Regional Administrator of the Environmental Protection Agency. The report catalogued emissions from oil and gas production in the Barnett Shale area. Her purported facts about the study findings are just plain wrong.

First, she claims that the report concluded that ozone precursor emissions from Barnett Shale production are twice as large as all mobile source emissions in the area. In fact, the report concluded that peak Barnett Shale emissions, while significant, were roughly comparable to emissions from cars and trucks (see press release accompanying the report).

White then claims that Dr. Armendariz’s study considered methane to be an ozone precursor, contrary to what is clearly stated in the report at p. 8. While it is true that methane does form ozone, albeit slowly, the report states “[m]ethane and ethane are specifically excluded from the definition of VOC” (volatile organic compounds). Thus, the report excluded methane from the comparison to mobile emissions of ozone precursors.

It is unclear if the author even read Dr. Armendariz’s work, which was not computer modeling, as she claims. Rather, it was an emissions “inventory,” a catalog of the air pollutant emissions from oil/gas sources in the Barnett Shale area, constructed using established engineering practices and industry-backed data sources. The core pieces of information for the inventory were oil/gas production data that are available for every county in Texas from databases at the Texas Railroad Commission. Dr. Armendariz’s resulting emissions estimates were in reasonable agreement with estimates issued by the Texas Commission on Environmental Quality later in 2009 (10-20% difference).

You can’t make a strong case when you get facts wrong. And, it is irresponsible for White to make her case by manipulating science, while cynically blaming government bodies of committing the same sin.

It’s time we all get the facts right and use science to expose truths, not veil our own agenda. For our part, EDF is working with leading academic researchers and industry leaders to conduct scientifically rigorous measurements of emissions from natural gas production. Leaks that occur during production (as well as distribution and use) stand to significantly undermine the potential of natural gas as a lower carbon energy source.

Also posted in Natural Gas, Texas / Comments are closed

Natural Gas: A Question Of Sustainability

By Elena Craft, PhD / Published: October 11, 2012

This commentary was originally posted on the EDF Texas Clean Air Matters Blog.

Today there are around 45,000 shale gas wells operating in the United States – triple the number in 2005 – and as a result, people are rightfully concerned about the extent of the shale boom’s potential damage to the environment.

The issue became the focal point of discussion this month in “Can Natural Gas Be Sustainable?,” a five-person panel presentation at the second annual SXSW Eco conference in Austin. As part of the panel, we discussed how stronger standards and employing best practices could minimize impacts of increased natural gas production in the wake of growing public concern about the health and environmental impacts of drilling.

Attendees of SXSW Eco represented a broad swath of perspectives, ranging from those who were against any natural gas development to those who wanted to see much more natural gas development. One attendee even criticized the title of the panel, presenting the position that developing any non-renewable resource is inherently not sustainable.

As for the sustainability question, one thing is clear: the natural gas industry has a lot of opportunity for improvement, and there is mounting public pressure to address environmental concerns. Nearly 61 percent of Americans have negative views about the oil and gas industry – higher than any other industry (David Blackmon, from FTI Consulting, actually joked that this was an improvement!)

As part of the discussion, I spoke about the many environmental and health impacts associated with natural gas development. Construction and drilling equipment can degrade local air quality with smog-forming pollutants and air toxics (Example: activities at the Barnett Shale in Texas). I also spoke about the implications of faulty well construction as one of the major causes of natural gas leakage, and emphasized that while natural gas is touted as a low-carbon fuel source, leaks from the production, distribution, and use of natural gas could undermine the greenhouse gas advantage combusted natural gas has over coal.

EDF is working hard to address the key problem areas associated with natural gas development: exposure to toxic chemicals and waste products; faulty well construction and design; climate impacts from methane leakage; local and regional air pollution; and land use and community impacts. Our team is engaging with community, government and industry stakeholders to help identify ways to minimize both human health and environmental risk, including:

Comprehensive disclosure of hydraulic fracturing chemicals
Modernization of rules for well construction and operation
Systems-based management of wastes and water
State and national standards for improving air quality and reducing climate impacts
Minimization of land use and community impacts from natural gas development

Fellow SXSW Panelists

Other speakers presented varying perspectives on natural gas issues. Chris Helman, Associate Editor of Forbes magazine, moderated the panel and emphasized the public interest on the topic, as well as the contribution of natural gas to the country’s energy portfolio.

George Peridas, a scientist from NRDC, prefaced his comments by saying, “We have a lot of work to do before we can call natural gas clean.” Peridas gave examples of numerous exemptions given the natural gas industry under the Safe Drinking Water Act, the Clean Water Act and the Clean Air Act. As well, those tasked with enforcing the state natural gas regulations that currently exist lack the ability to go out, fully inspect and enforce those standards. The result, he said, was that “industry is a self-policing entity right now.”

Much of his policy work focuses on climate change and correspondingly, Peridas said that natural gas could help with climate change and air quality when compared to coal. “The key is that gas needs to displace dirtier fuels,” he said. “A bridge is not the right frame of mind, and we cannot afford to treat gas as an abundant resource. We need to address its impacts now.”

Some of the solutions Peridas proposed included: designation of “off-limits” areas that provide fresh water resources or wildlife/conservation value; stopping those leaks that waste methane and contribute to greenhouse gas emissions; development of a comprehensive guide for how to drill safely (e.g., proper cement jobs at well sites); repealing the outrageous exemptions at the federal level that industry currently enjoys; focusing on measures and policies that promote solutions (e.g., solar energy); and ensuring that communities have a say in whether drilling proceeds in their areas.

Sister Elizabeth Riebschlaeger, a nun with Congregation Of The Sisters Of Charity Of The Incarnate Word, and community advocate for the Eagle Ford Shale, agreed strongly with co-panelist George Peridas and his push for more local regulations. She told the story of citizens in small, rural Texas towns being strongly impacted by the Eagle Ford shale, and even used the phrase “merciless exploitation” to describe her own such experience.

Sister Elizabeth asked the rhetorical question: “Are we counting our natural gas clean energy chickens before they hatch?” She then emphasized that society must consider all of the activities required to produce natural gas, including activities she has observed in the Eagle Ford Shale: trucks and heavy equipment; travel trailers for workers; transporting of sand and chemicals, fracking equipment, and toxic waste (produced during operations); construction of huge batteries and tanks; rigs operating 24 hours a day; loud compressor stations; damage to land requiring clean up; and more.

David Blackmon, managing director at FTI Consulting, represented industry’s point of view, which touts the “reality that over half of our electricity generating capacity is natural gas.” The demand for natural gas includes backing up intermittent supply from solar and wind power. He said that natural gas was one of the only power sources that could be “cycled up” in a matter of minutes and that coal made this process more expensive.

Blackmon said that the key to making natural gas sustainable was ensuring public trust; trust that it is being appropriately regulated at federal, state and local levels. “I absolutely agree that there are not enough inspectors in the Texas Railroad Commission to regulate it,” he said. “The good news is that most companies in the industry recognize the need for public trust and are working towards that.”

Also posted in Natural Gas / Tagged fracking, Methane Leakage, Natural Gas | Read 2 Responses

New Study To Provide Important, Direct Measurement Data On Methane Emissions From Natural Gas Production

By Steven Hamburg / Published: October 10, 2012

While natural gas burns cleaner than other fossil fuels when combusted, methane leakage from the production, transportation, and use of natural gas has the potential to undermine some or all of those benefits, depending on the leakage rate. Methane is the main ingredient in natural gas and a greenhouse gas (GHG) pollutant many times more potent than carbon dioxide (CO2), the principal contributor to man-made climate change.

In other words, leaks during the production, distribution, and use of natural gas could undermine, and possibly even overwhelm, the greenhouse gas advantage combusted natural gas has over coal and spell major trouble for the climate.

Up to this point, direct measurement data on methane leakage rates has been limited and subject to wide interpretation and debate. Some studies have estimated the leak rate to be as high as 7.9%, while others have estimated the leak rate to be as low as 1% for some aspects of the drilling process. Methane leakage matters, and has clear implications on whether natural gas can be seen as a lower carbon energy source. To help overcome some of the debate, EDF is working with leading academic researchers and industry leaders from across the natural gas sector to take direct measurements of leak rates to help better define the natural gas leak rate across the natural gas supply chain in the United States.

In partnership with the EDF and nine leading natural gas producers, today the University of Texas Austin (UT) announced the first part of this study, focused on emissions from natural gas production. The study will help provide a clearer picture of methane leakage rates occurring at natural gas drilling sites around the country. It is particularly relevant because drilling and completion processes have evolved rapidly in recent years – thanks to breakthroughs in horizontal drilling and hydraulic fracturing – and the knowledge about the methane leaked during this shift has not.

The main objective of this study on production emissions is to obtain scientifically rigorous data from multiple gas producing basins. The study will focus on quantifying emissions from well completions, gas well liquid unloading and well workovers, in addition to other more routine well-site fugitive emissions, the areas of the production process with the greatest leak rate uncertainties

The study is unique in that it brings multiple, key stakeholders to the table to make measurements of emissions at the well pad that will be shared when completed. If natural gas is to become an accepted part of an energy independence strategy, while supporting a clean energy future, it is critical to work together to quantify, and where ever possible lower, the existing methane leakage rate. Such an approach could yield enormous added environmental and health benefits from existing and future natural gas infrastructure.

A research team led by UT, including engineering and environmental testing firms URS and Aerodyne Research, is conducting the extensive field study. Project partners include EDF, Anadarko Petroleum Corporation, BG Group plc, Chevron Inc., Encana Oil & Gas (USA) Inc., Pioneer Natural Resources Company, Shell, Southwestern Energy, Talisman Energy, USA, and XTO Energy, an ExxonMobil subsidiary.

For more information on ways to get sustained benefits from natural gas, EDF published a paper earlier this year titled, “Greater focus needed on methane leakage from natural gas infrastructure.” Find more at edf.org/methaneleakage.

Also posted in Natural Gas / Read 3 Responses

Natural Gas – A Briefing Paper For Candidates

By Eric Pooley / Published: August 10, 2012

To download a copy of this briefing paper, please click here.

Hydraulic fracturing and horizontal drilling, processes used to extract natural gas from underground shale formations, have unlocked vast new domestic reserves — an unexpected abundance that has overturned many of America’s assumptions about energy. Every major-party candidate for public office in 2012, Republican or Democrat, must understand this new energy reality. And though each candidate’s position on natural gas development is likely to begin with a recognition of shale gas’s economic and energy security benefits, mastery of the issue requires a deeper level of understanding. Shale gas also brings with it a set of serious risks to public health and the environment — including impacts to water, air, land, local communities and the earth’s climate. At the local level in areas where shale gas production is intense, legitimate concerns over health and environmental impacts are shared by Republican, Democratic, and independent voters alike. No candidate’s position on natural gas can be considered complete unless it addresses these impacts.

In 2001, shale gas accounted for just 2% of America’s natural gas supply. Today, it accounts for more than 30% — while more than 90% of all new oil and gas wells being drilled in the U.S. make use of hydraulic fracturing. As unconventional natural gas production spreads into populous regions that are not accustomed to intensive industrial activity, its impacts have made it the object of intense local opposition, as manifested in the July 28th “Stop the Frack Attack” rally in Washington D.C and others like it in state capitals around the country. The environmental and public health concerns of local communities must be addressed if natural gas companies are to maintain their social license to operate.

Economic Benefits

While a majority of Americans remain unfamiliar with hydraulic fracturing, or “fracking,” according to a recent University of Texas poll, many will certainly applaud the economic benefits of low-cost natural gas. The natural gas revolution is driving:

Job creation across the value chain, with rising demand for technical and professional services, for steel, pipelines and storage facilities, and for all the ancillary goods and services that arise in support of a rapidly growing industry.
An unexpected expansion in the American chemical industry, with Dow and DuPont now building new plants close to shale formations. “If you had told me 10 years ago I’d be standing up on this podium making this announcement [about Dow’s $4 billion investment in four new Texas chemical plants], I would not have believed you,” Dow CEO Andrew Liveris said in April. “The cost of energy, the cost of feedstocks … was pricing the United States out of the market,” he said. But the shale “miracle” changed that.
A revival in U.S steelmaking and other manufacturing industries. Nucor, which uses natural gas to make steel, is building a $750-million facility in Louisiana, just eight years after shutting down a similar plant in the same state.
A new sense of the potential for U.S. energy independence and energy security.

Environmental Benefits

Increased development of shale gas could yield substantial environmental and public health benefits while helping the U.S. energy infrastructure become cleaner and less carbon-intensive. This highly desirable outcome will only be achieved, however, if the resource is developed responsibly. The potential exists because natural gas:

Produces only about half the carbon dioxide of coal when burned.
Produces about a third as much of the smog-forming nitrogen oxides that come from burning coal.
Produces almost none of the mercury and sulfur dioxides that come from burning coal or oil.

For this reason, fueling power plants with natural gas instead of coal can dramatically cut conventional air pollution, can help reduce greenhouse gas emissions from the power sector and could help turn the tide against mountaintop removal mining and other environmentally disastrous industry practices. And because natural gas-fired power plants can cycle up quickly, they can be a nimble enabler of intermittent renewable energy sources in combination with demand response and emerging large-scale energy storage technologies.

Critically, if U.S. industry and regulators are successful in measuring and reducing methane pollution, which undermines natural gas’ role as a lower carbon alternative to coal and oil, the shale gas revolution can also bring a reduction in short-term radiative forcing — the driver of global climate change — over the next several decades. Leak reduction will determine how much of a role natural gas can play in a clean, low carbon future.

In short, natural gas could be a win-win benefiting both the economy and the environment — if we do it the right way. The right way means putting tough rules and mandatory environmental safeguards in place that protect communities and reduce methane pollution. There is no question that domestic unconventional gas supplies are leading to coal-fired power plants being retired. The public recognizes this benefit, but the jury is still out on whether shale resources can be produced responsibly. It’s no simple task to strike a balance between public safety and the development of this crucial energy resource, but it is essential that we do so. Americans deserve assurance that the economic, environmental and energy security benefits of shale gas development will be realized without sacrificing their health, safety, or the protection of the environment.

Clearly there are environmentally sensitive areas that should be off limits to natural gas development. And just as clearly there are some areas where intensive development will occur. Environmental Defense Fund is working with partners from academia, civil society, and industry to identify and minimize the impacts from the full range of gas development activities. Horizontal drilling and hydraulic fracturing attract significant press attention, but the issues of gas production are much broader than that.

Specific Areas of Concern

EDF sees five areas in which strong rulemaking is necessary:

Mandating greater transparency in industry operations. Having good data is a prerequisite to understanding and mitigating risks, and it’s the first step toward winning back a badly damaged public trust. Regulators should require, and companies should embrace, disclosure policies that mandate reporting of not only the chemicals used in hydraulic fracturing, but also chemicals used in drilling and operating wells – as Ohio Governor John Kasich has advocated. Transparency should also be brought to other aspects of industry operations, such as detailed reporting of air emissions, chemical characterization of waste streams and tracking and reporting of water use and waste disposition. Company compliance histories should also be catalogued and reported, so companies with good records can get the credit they deserve and bad actors can be identified and pushed to improve performance.
Modernizing rules for well construction and operation. Poor well construction and operation can lead to groundwater contamination and to blowouts that can endanger lives and foul the surface environment. In response, EDF is working with regulators and key stakeholders to strengthen rules for proper construction and operation of hydraulically fractured wells. While stronger regulatory oversight of well construction is needed, no one should try to suggest that hydraulic fracturing itself is risk free. Both aspects of well development need strong oversight.
Strengthening regulations for waste and water management. Poor handling, storage and disposal of production fluids and other wastes is a major issue; chemical spillage is the leading cause of groundwater contamination from gas development activities. In response, EDF is pressing for measures to reduce spills, improve the use and handling of chemicals, and assure proper disposal (or recycling) of produced water. As mentioned above, a key missing ingredient here is better data on the chemical composition of waste streams. To be confident that handling, treatment and disposal practices are sufficient, authorities must know what substances are being handled. Finally, headline-grabbing reports of earthquakes connected to shale gas development have been linked to the waste disposal method known as deep well injection, not to hydraulic fracturing itself. This issue points to the need for improved seismic analysis prior to permitting of deep injection wells.
Improving regulations to protect local and regional air quality. Air emissions resulting from the production, storage, processing, and transportation of natural gas can threaten public health. Leaks and routine venting during the extraction, processing and transportation of natural gas result in emissions of greenhouse gases and, depending on the local composition of unprocessed gas, other pollutants that contribute to locally- and regionally-elevated air pollution. In 2009, an SMU study estimated that the combined amounts of volatile organic compounds (VOC) and nitrogen oxide (NOx) emissions from oil and natural gas production in the Barnett Shale of North Texas were comparable to amounts of those emissions from the roughly 4 million cars and trucks in the adjoining Dallas Fort-Worth metro area. Fortunately, widely available and cost-effective remedies exist: repairing worn equipment, using “green” well completion techniques and eliminating venting are just a few. In the past five years, for example, Southwestern Energy says it has cut the cost of capturing stray emissions from $20,000 a well to close to zero. The company is capturing an average of 16 million cubic feet of gas that would otherwise have been released or flared. Southwestern also uses special pop-off valves to make sure natural gas is not released into the air from well casings. If pressure causes a valve to open, the gas is captured in a closed loop that returns it to the system, saving the resource. These systems cost just $600 to $1200 a piece.
Developing innovative strategies to reduce community impacts. The cumulative impact of infrastructure development, traffic, noise, lights, and the like can overwhelm communities and intrude on sensitive ecosystems and habitats; none of this is easily addressed through conventional regulatory approaches. Instead, EDF recommends that states and local governments bring together stakeholders for scientifically based, bottom-up planning processes designed to address unique local needs. Likewise, the right of local communities to regulate the location of gas development through local zoning ordinances must be preserved. Gas operations shouldn’t receive special carve-outs from traditional local powers that other industrial activities must comply with.

President Obama has voiced his commitment to domestic energy production through safe and responsible natural gas development, declaring that “America will develop this resource without putting the health and safety of our citizens at risk.” EDF would like to see Governor Romney and other candidates across the land call for the same careful balance. Far from being an example of regulation that chokes economic growth, strong oversight of natural gas development is necessary to ensure the sector’s continued growth, by avoiding the public backlash that could slow or even derail natural gas development. Read More »

Also posted in Natural Gas, Washington, DC / Tagged Energy Policy, fracking, Natural Gas Policy | Read 11 Responses

What Will It Take To Get Sustained Benefits From Natural Gas?

By Ramon Alvarez, Ph.D. / Published: April 10, 2012

Natural gas is reshaping our energy landscape. Though the potential energy security and economic benefits are compelling, the challenge is that natural gas comes with its own set of risks to public health and the environment, including exposure to toxic chemicals and waste products, faulty well construction and design, local and regional air quality issues and land use and community impacts.

There has also been much confusion about the impacts of increased natural gas use on the climate. While natural gas burns cleaner than other fossil fuels when combusted, methane leakage from the production and transportation of natural gas has the potential to remove some or all of those benefits, depending on the leakage rate. Methane is the main ingredient in natural gas and a greenhouse gas (GHG) pollutant many times more potent than carbon dioxide (CO2), the principal contributor to man-made climate change.

Proceedings of the National Academy of Sciences (PNAS) Paper

EDF has teamed up with several respected scientists to find a better way to examine the climatic impacts of increased use of natural gas and compare it in place of other fossil fuels in a paper titled “Greater Focus Needed on Methane Leakage from Natural Gas Infrastructure” published yesterday in the Proceedings of the National Academy of Sciences (PNAS). While methane absorbs more heat energy than CO2, making it a much more potent GHG, it also – luckily – has a shorter duration in the atmosphere. The combination of these factors makes it difficult to compare methane emissions to other GHGs using conventional methods.

Instead, in the PNAS paper, we propose the use of an enhanced scientific method: Technology Warming Potentials (TWPs). Specifically, this approach reveals the inherent climatic trade-offs of different policy and investment choices involving electricity and transportation. It illustrates the importance of accounting for methane leakage across the value chain of natural gas (i.e. production, processing and delivery) when considering fuel-switching scenarios from gasoline, diesel fuel and coal to natural gas. TWPs allow researchers, policy makers and business leaders to make fuel and technology choices while better accounting for their climate impacts.

PNAS Paper Key Findings

We illustrated the new approach by analyzing commonly discussed policy options. Using the Environmental Protection Agency’s (EPA) best available estimated leakage rate of 2.1% of gas produced (through long-distance transmission pipelines but excluding local distribution pipelines), generating electricity from natural gas in new combined cycle power plants decreases our contribution to climate change, compared to new coal-fired plants. This is true as long as methane leakage rates stay under 3.2%.

Natural gas powered cars, in contrast, do not reduce climate impacts unless leakage rates are reduced to 1.6% (compared to our estimate of current “well-to-wheels” leakage of 3.0%). In heavy trucks, the reduction would need to be even more pronounced—converting a fleet of heavy duty trucks to natural gas damages the climate unless leakage is reduced below 1.0%.

The PNAS paper only provides illustrative calculations with EPA’s current estimate of the methane leakage rate and better data is needed to more accurately determine leak rates. Measuring how much gas is lost to the atmosphere and where the leaks are occurring will help to further target leak reduction opportunities to ensure that natural gas will help mitigate climate change. EDF is working to obtain extensive empirical data on methane released to the atmosphere across the natural gas supply chain, since the climatic bottom line of fuel switching scenarios involving natural gas is very sensitive to this parameter.

Not only is the data on methane leakage far from definitive, but climate impacts from leakage – and other key public health and environmental risks – could be reduced by strong standards and improved industry practices. There are many practices and technologies already being used in states such as Colorado and Wyoming, and elsewhere by natural gas companies to reduce gas losses, which results in greater recovery and sale of natural gas, and thus increased economic gains. The return on the initial investment for many of these practices is sometimes as short as a few months and almost always less than two years. In these tough economic times, it would seem wise to eliminate waste, save money and reduce environmental impact.

In sum, the paper’s results suggest that methane leakage rates matter: they can materially affect the relative climate impacts of natural gas over coal and oil. While the paper does not draw hard and fast conclusions about the future implications of fuel switching, it does provide guidance in terms of the leak rates necessary for fuel switching to produce climate benefits at all points in time.

EDF Methane Leakage Model

We also released a new methane leakage model, based on the science described in the PNAS paper, which allows anyone to test a range of scenarios to quantify the climate benefits, or damages, of natural gas production and usage given specific methane leakage rates. Users can vary the key system attributes independently to see how they affect net radiative forcing (the primary index used to quantify the effect of greenhouse gases [GHGs] on global temperatures) from U.S. emissions over time. Visit http://www.edf.org/methaneleakage to plug in different variables and observe the outcome.

For more information, visit http://www.edf.org/methaneleakage.

Also posted in Natural Gas / Read 1 Response