DENTON, Texas — Natural-gas wells here can be found just beyond the hedgerows of new subdivisions, and close by the hangars at the municipal airport. Their tunnels extend deep underneath a city park, a golf course and the University of North Texas football stadium.
The wells draw from the Barnett Shale, a geological formation once thought too dense to be profitably tapped for energy. Then, in 1997, crews deploying water under high pressure with chemicals and sand learned how to fracture the shale rock and release vast new supplies of natural gas — a process known as fracking.
That technology has reshaped America’s energy industry, with shale gas now produced in more than a dozen states. And, President Obama is touting the expansion in natural-gas-generated electricity, which produces roughly half the carbon emissions of coal, as a bridge to the nation’s energy future.
But natural gas is no long-term fix in the effort to shield the world from the most severe effects of climate change or meet the difficult goal set by Obama and other world leaders to keep global temperatures from rising no more than 2 degrees Celsius.
Some experts say unfettered burning of natural gas, without adding systems to capture carbon emissions, will significantly undermine that effort.
“Gas may be the cleanest of fossil fuels, but it is still a fossil fuel,” said Maria van der Hoeven, executive director of the International Energy Agency, in a July speech. “The widespread use of gas without emissions abatement would leave us with no chance of meeting our 2- degree climate goal.”
The ability of natural-gas use to combat climate change is further eroded by leakage from the production, processing and transport of the fuel. Methane is the primary component of natural gas, and when vented rather than burned for energy, it acts as a short-lived but potent greenhouse gas.
Related: Leaked U.N. climate report: 75 percent of reserves must stay in the ground
The sheer abundance of natural gas also could work against efforts to limit climate change. If big supplies keep prices low, then natural gas could slow the development of alternative sources of energy that could help meet the 2050 goals.
A study released in 2013 by Stanford University’s Energy Modeling Forum found that natural gas in the decades ahead is likely to replace not only high-carbon coal but also zero-carbon fuels like nuclear, which now provides nearly 20 percent of the nation’s electricity.
Last year, for example, a nuclear-power plant in Wisconsin shut down because it could no longer compete in markets driven down by low-cost natural gas. More nuclear-plant closures are forecast in the years ahead.
Tracking these trends, the Stanford study concluded that a surge in natural-gas use spurred by the fracking technology would have “relatively modest impacts” on carbon emissions through 2050.
“You might see some downturn, but it’s not any kind of a game changer,” said Hillard Huntington, executive director of Stanford University’s Energy Modeling Forum. “Shale gas development is not a big winner from a climate point of view.”
The fracking boom began in the farmlands outside Denton, where George Mitchell, a gas and oil driller, spent more than 15 years experimenting with tapping the Barnett Shale that underlies numerous Texas counties.
Mitchell, the son of a Greek goat herder, was an industry maverick. He studied chemical engineering at Texas A&M. But he also attended seminars at the Aspen Institute, where he was influenced by Buckminster Fuller, the inventor and philosopher who spoke about developing a new ethic of sustainability.
Mitchell, who died last year, championed gas as a cleaner fuel than coal and wanted to find ways to dramatically increase production. Traditional wells tapped into pockets of gas trapped underground, but Mitchell was convinced that vast amounts could be liberated from source rocks.
Mitchell’s breakthrough came in 1997 as his crews abandoned a costly gel used in fracking in favor of a much cheaper mix of water, chemicals and sand.
In the first few months after fracking, Mitchell’s crews worried the flow from that fracked well would fade. It didn’t, and in the years that followed, horizontal drilling was found to free up even more shale gas.
“There is so much gas out there. All we have to do is turn on the tap,” said Chip Minty, of Devon Energy, a major developer of fracked wells. “Unlike any time in the history of the oil and gas business … we can get it when we need it. And we will.”
Today, some 18,000 wells have been drilled into the Barnett Shale. Their concrete pads are scattered over the farm fields and pasture lands, and now in towns and cities such as Denton. Nationwide, shale-gas fields helped boost total U.S. natural-gas reserves by 35 percent during the two-year period ending in 2008.
The technology is evolving so quickly that wells drilled in Denton less than a decade ago already are being redrilled to frack more gas-rich shale.
“I hate to say it like this. A lot of times we buy other people’s garbage, and we are taking their garbage and recycling it,” said Mark Grawe, chief operating officer of EagleRidge Energy, which in recent years has been the most active drilling company in Denton.
Health, safety concerns
As fracking has grown, so too have the safety and health concerns.
In some areas of the country, increased fracking has been accompanied by a dramatic surge in earthquakes. Researchers also are assessing the risks that reinjected wastewater from fracking sites could pose to drinking-water aquifers, and are looking at the possible effects on lakes and steams of runoff from fracking sites.
Outside of Denton, population 123,000, the small town of Dish has some 60 gas wells as well as a station where gas is pressurized for transport. Residents complain of headaches, nosebleeds, nausea and other health problems that they believe are linked to air pollution. Some families, including that of a former mayor, ended up leaving.
In Denton, residents who live near gas development are concerned about whether their health is compromised by exposure to air pollutants such as benzene, a carcinogen.
More recently, residents of a subdivision built within 300 feet of EagleRidge wells were angered by fumes, noise, nighttime lights, gas flaring and truck traffic close by their homes. This year, they filed a $25 million lawsuit against EagleRidge.
Grawe, of EagleRidge, says he tried to minimize the impacts of the operation.
“The perception has been that we don’t care about anything, and are just out to do whatever we want,” he said. ” But I’ve been out at night talking to people about their concerns about noise and light. I’m just as concerned about the environment as they are.”
The drilling so close to this subdivision helped spur a petition drive to ban fracking in the city, and that proposal — an idea rejected by the city council — will be on the ballot this fall. If passed, the ban would be a first for a major Texas city.
“There were people who we were working with who thought that was too radical a measure. But when that fracking started by those homes, everyone said they have just crossed the line to a level of brutality that is unacceptable,” said Cathy McMullen, a Denton home health nurse who helped organize the petition drive.
Tracking methane leaks
On a warm fall morning, a small plane lifted off from the Denton municipal airport on a hunt for methane gas that leaks into the atmosphere.
These aerial surveys have been carried out in Texas, Colorado, Pennsylvania and elsewhere, in aircraft packed with sophisticated monitoring equipment that can distinguish methane produced by the industry from that of other sources, such as stockyards or landfills.
These results are key to figuring out what role natural gas plays in triggering climate change.
Methane is the main component of natural gas. During the first 20 years after its release, a pound of methane is some 84 times more potent in trapping sunlight than is carbon dioxide, the much longer-lived gas released when any fossil fuel is burned for power production.
The Environmental Protection Agency estimates that some 2.4 percent of the annual production of natural gas leaks into the atmosphere as methane.
Aerial surveys in several states indicate that the leak rates may be much higher than the EPA estimates. In Utah, one study indicated that the rate, at times, topped 9 percent.
But there also are signs of progress.
The process of preparing a gas well for commercial production, for example, has been a major source of vented methane. During completion, gas mixed with water flows to the surface and typically has been released into the atmosphere from an open tank. A University of Texas study found that new equipment, which next year will be required by EPA regulations, can reduce these emissions by 99 percent.
Paul Shepson, a Purdue University researcher involved in the Denton surveys, believes most of that methane can eventually be contained.
“I don’t worry so much about methane leaks. We will find the leaks and fix those problems,” Shepson said.
Even if that happens, producing power from natural gas will remain a significant contributor to climate change so long as carbon emissions continue to be released during combustion.
“The real issue is about the CO2 emissions we are committing to,” Shepson said. “The United States is reinvesting in fossil fuels as a power source, and we will keep using natural gas as long as it’s cheap.”
Hal Bernton: 206-464-2581 or email@example.comAlex Krouse, Melanie Lawder and Carolyn Portner contributed research while students at Marquette University.