Studies Say Natural Gas Has Its Own Environmental Problems

Tom Zeller Jr. New York Times 11 Apr 11;

Natural gas, with its reputation as a crucial linchpin in the effort to wean the nation off of dirtier fossil fuels and reduce global warming, may not be as clean over all as its proponents say.

Even as natural gas production in the United States increases and Washington gives it a warm embrace as a crucial component of America’s energy future, two coming studies try to poke holes in the clean-and-green reputation of natural gas. They suggest that the rush to develop the nation’s vast, unconventional sources of natural gas is logistically impractical and likely to do more to heat up the planet than mining and burning coal.

The problem, the studies suggest, is that planet-warming methane, the chief component of natural gas, is escaping into the atmosphere in far larger quantities than previously thought, with as much as 7.9 percent of it puffing out from shale gas wells, intentionally vented or flared, or seeping from loose pipe fittings along gas distribution lines. This offsets natural gas’s most important advantage as an energy source: it burns cleaner than other fossil fuels and releases lower carbon dioxide emissions.

“The old dogma of natural gas being better than coal in terms of greenhouse gas emissions gets stated over and over without qualification,” said Robert Howarth, a professor of ecology and environmental biology at Cornell University and the lead author of one of the studies. Mr. Howarth said his analysis, which looked specifically at methane leakage rates in unconventional shale gas development, was among the first of its kind and that much more research was needed.

“I don’t think this is the end of the story,” said Mr. Howarth, who is an opponent of growing gas development in western New York. “I think this is just the beginning of the story, and before governments and the industry push ahead on gas development, at the very least we ought to do a better job of making measurements.”

The findings, which will be published this week, are certain to stir debate. For much of the last decade, the natural gas industry has carefully cultivated a green reputation, often with the help of environmental groups who embrace the resource as a clean-burning “bridge fuel” to a renewable energy future. The industry argues that it has vastly reduced the amount of fugitive methane with new technologies and upgraded pipe fittings and other equipment. Mark D. Whitley, a senior vice president of engineering and technology with Range Resources, a gas drilling company with operations in several regions of the country, said that the losses suggested by Mr. Howarth’s study were simply too high.

“These are huge numbers,” he said. “That the industry would let what amounts to trillions of cubic feet of gas get away from us doesn’t make any sense. That’s not the business that we’re in.”

Natural gas is already the principal source of heat in half of American households. Advocates like the former oil tycoon T. Boone Pickens have also long sought to promote it as a substitute for coal in electricity generation or gasoline in a new generation of natural gas cars. And the development of new ways to tap reserves of natural gas means production is likely to increase sharply.

Two weeks ago, President Obama included natural gas in his vision for America. Clark Stevens, a White House spokesman, said that the administration’s energy priorities were not about picking one energy source over another, but about diversifying the nation’s energy mix. “This process will continue to be based on the best science available to ensure our energy sources, including our nation’s natural gas reserves, are developed safely and responsibly,” Mr. Stevens said on Friday.

The ability to pull natural gas economically from previously inaccessible formations deep underground has made huge quantities of the resource available in wide areas of the country, from Texas, Louisiana, Pennsylvania, New York, Wyoming and Colorado.

Such unconventional gas production accounts for roughly nearly a quarter of total production in the United States, according to the latest figures from the Energy Information Administration. That is expected to reach 45 percent by 2035.

But the cleanliness of natural gas is largely based on its lower carbon dioxide emissions when burned.. It emits roughly half the amount of carbon dioxide as coal and about 30 percent that of oil.

Less clear, largely because no one has bothered to look, are the emissions over its entire production life cycle — that is, from the moment a well is plumbed to the point at which the gas is used.

Methane leaks have long been a concern because while methane dissipates in the atmosphere more quickly than carbon dioxide, it is far more efficient at trapping heat. Recent evidence has suggested that the amount of leakage has been underestimated. A report in January by the nonprofit journalism organization ProPublica, for example, noted that the Environmental Protection Agency had recently doubled its estimates for the amount of methane that is vented or lost from natural gas distribution lines.

Chris Tucker, a spokesman for Energy in Depth, a coalition of independent oil and natural gas producers, dismissed Mr. Howarth as an advocate who is opposed to hydraulic-fracturing or “fracking,” a practice associated with unconventional gas development involving the high-pressure injection of water, sand and chemicals deep underground to break up shale formations and release gas deposits. Mr. Howarth said his credentials as a scientist spoke for themselves.

Mr. Howarth included methane losses associated with flow-back and drill-out processes in hydraulic fracturing and other unconventional gas drilling techniques.

The study combined these emissions with studies of other methane losses along the processing and distribution cycle to arrive at an estimated total methane loss range from 3.6 to 7.9 percent for the shale gas industry.

The researchers also include a recent study from the Goddard Institute for Space Studies at NASA suggesting that an interaction of methane with certain aerosol particles significantly amplifies methane’s already potent greenhouse gas effects, particularly over a 20-year time horizon. When all is factored together, Mr. Howarth and his colleagues conclude that the greenhouse gas footprint of shale gas can be as much as 20 percent greater than, and perhaps twice as high as, coal per unit of energy.

David Hughes, a geoscientist and research fellow at the Post Carbon Institute, an energy and climate research organization in California, used Mr. Howarth’s research as part of a broader look at natural gas as a substitute for coal in electricity generation and oil in transportation.

Mr. Hughes’s full report is scheduled to be released in May, but in a draft version shared with The New York Times, Mr. Hughes suggested that while natural gas would play an important role in the nation’s energy mix, both cases were practical impossibilities.

“I think it’s going to be very challenging, to put it mildly, to ramp up shale gas production by fourfold, which is the federal government’s projection for 2035,” Mr. Hughes said. “I’m not saying it can’t be done, but if it was done, the amount of drilling you’re looking at to make that happen is staggering.”

Mr. Hughes, using Mr. Howarth’s calculations, also concludes that replacing coal with natural gas for base load electricity production will most likely make greenhouse gas emissions worse. It would be better, he argues, to improve energy efficiency, rely on natural gas in niche vehicle markets and balance continued construction of wind and solar power to produce electricity.

David Hawkins, the director of climate programs with the Natural Resources Defense Council, said that much could be done by regulators to nudge drillers to capture more of the fugitive methane, but that it’s often more economical for industry to simply let it escape.

Mr. Hawkins also said that too little was known about just how much methane was being lost and vented, and that studies like Mr. Howarth’s, while needed, relied on too slim a data set to be considered the final word.

“This is a huge and growing industry, and we just don’t have the information we need to make sure that this resource is being developed as cleanly as it can be,” Mr. Hawkins said.

“We view his shining a flashlight into this dark closet to be a service,” Mr. Hawkins added, “but the flashlight is still a dim one, and we still can’t see everything in the closet.”

Shale gas as dirty as 'oil, coal': study
Yahoo News 12 Apr 11;

PARIS (AFP) – Shale gas, an energy source enjoying a boom in North America and Europe, carries a greater carbon footprint than oil, coal and conventional gas over at least a 20-year period, according to a study released on Tuesday.

Scientists led by Robert Howarth from New York's Cornell University looked at greenhouse-gas emissions from the extraction of shale gas in the US, drawing on data from the oil and gas industry and from a federal auditing agency, the General Accountability Office (GAO).

Shale gas holes up in a dense sedimentary rock which is fractured by large volumes of water and chemicals that are piped in horizontally under high pressure.

After the fracturing, large amounts of water returns to the surface within a few days, along with significant amounts of methane, which comprises the bulk of the shale gas.

The problem, though, is that methane is a potent greenhouse gas as well as as a fuel, and large amounts of it leak from shale-gas extraction, said the study.

During the life cycle of an average shale-gas well, between 3.6 percent and 7.9 percent of the well's total production is emitted to the atmosphere as methane, it said.

This comes through routine venting, equipment leaks and emissions that are included in the water flowback.

These leaks are at least 30 percent more than -- and perhaps more than twice as great as -- those from conventional gas, although their emissions from routine production and downstream operations are the same, it said.

Methane is more than 20 times more efficient than carbon dioxide (CO2), the principal greenhouse gas emitted by fossil fuels, for trapping solar heat.

But it lingers in the air for only between nine and 15 years, whereas a molecule of CO2 stays around for a century or more.

"The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years," said the paper.

"Compared to coal, the footprint of shale gas is at least 20 percent greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years."

The study is published online in Climatic Change Letters, part of the Springer stable of journals.

Major investments are being made in shale gas in the United States and in Europe.

They are based in part on the goal of reducing geopolitical risk from imported conventional gas but also on the contention that shale is cleaner than oil and coal because it releases less CO2 for every unit of energy it provides.

It thus can be a useful transitional energy towards a low-carbon economy, according to this argument.

According to the US Department of Energy, total domestic production of natural gas will grow by 20 percent by 2035. Shale gas alone will increase its share of production from 16 percent in 2009 to 45 percent in 2035.

"The large greenhouse gas footprint of shale gas undercuts the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming," said Howarth.

"The full footprint should be used in planning for alternative energy futures that adequately consider global climate change."

Shale Gas Pollutes More Than Coal, Study Finds
Daniel Trotta PlanetArk 13 Apr 11;

An abundant source of U.S. natural gas widely seen as a cleaner alternative to oil and coal is in reality the fossil fuel that creates the most greenhouse gas emissions, a study concludes.

The paper led by Cornell University ecology professor Robert Howarth raised howls of protest from the gas industry, which said the document was political.

The study contends that so much methane escapes from the extraction of shale gas over the life of a well that it allows more heat-trapping greenhouse gas into the atmosphere than coal.

The report acknowledged that natural gas is cleaner to burn than other fuels but that greater pollution derives from leakage, whether accidental or purposely designed to relieve well pressure.

Improved technology could solve the problem but Howarth in an interview doubted whether that was economical considering stubbornly low natural gas prices. A North American boom in the production of shale gas, billed as an alternative to foreign oil, has depressed gas prices even while oil has soared.

Industry representatives criticized the work as sloppy and incomplete advocacy against shale gas. The shale boom previously had raised more alarm from environmentalists because of the threat of chemicals seeping into ground water through the drilling process known as hydraulic fracturing, or "fracking."

For an index of shale gas companies, double-click on.

Some 3.6 percent to 7.9 percent of the methane from shale gas production leaks into the atmosphere, releasing a greenhouse gas that is especially potent over the first 20 years, the study said.

"The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years," said the study, which can be seen here%20et%20al%20%202011.pdf.

"Compared to coal, the footprint of shale gas is at least 20 percent greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years."

Such conclusions break conventional thinking and sound outrageous to industry representatives, who said Howarth exaggerated the amount of highly valuable gas purportedly allowed to escape.

"The problems with the study boil down to two basic areas: the data and the assumptions. Apart from that, Mrs. Lincoln, it's a terrific study," Chris Tucker, spokesman for the industry group Energy In Depth, said in a statement.

"This isn't a serious academic pursuit, but rather a serious political one," Tucker said.

A more detailed response can be seen here

Howarth defended his work as meeting strict academic and scientific standards."It's being published in a highly respected journal and has been rigorously peer-reviewed," Howarth said. "This is not advocacy. This is science."

The criticism of Howarth work began more than a year ago when he reported preliminary findings in a two-page summary. Since then Howarth has issued periodic updates.

The final paper, co-written with Renee Santoro and Anthony Ingraffea, had been due to be published in the journal Climatic Change Letters on Thursday but was made available on Tuesday after it was released by The Hill newspaper.

(Editing by Alden Bentley)