As the world's easy-access oil supplies dry up, North America is increasingly turning to unconventional sources—such as drilling in the deep sea, mining oil sands, and using hydraulic fracturing (fracking) to recover oil and natural gas from shale deposits—to feed our cars and power plants. The unconventional hydrocarbon industry has been growing rapidly in recent years. Shale gas production in the Northeast United States is increasing by 25 percent each year, while shale oil production at the Bakken formation in North Dakota is increasing by 35 percent a year.
Despite the rapid growth, many questions remain about the impact of these new extraction techniques on the environment, the economy, and human health. And as Popular Mechanics reported in a 2011 cover story, there's no clear-cut answer on whether these technologies are good or bad. This week, a panel of geologists and PM editor-in-chief Jim Meigs gathered to discuss the sustainability of unconventional energy extraction.
"With fracking you have all sorts of really interesting, subtle, complicated issues that are legitimate and difficult to summarize in a fair way for the public," Meigs said at the seminar, which was hosted by Columbia University. There's plenty of good, bad, and unknowns:
Moving toward energy independence. The International Energy Agency (IEA) predicts that the U.S. could be 97 percent energy self-sufficient by 2035. Sarah Odland, a business manager in Columbia's Earth and Environmental Sciences department, says that shift toward energy independence will rely heavily on unconventional oil and gas extraction. Shale deposits in and around North Dakota may contain around 7.4 billion barrels of oil, according to a recent estimate from the USGS, while the Marcellus Shale alone—a huge formation beneath Pennsylvania and surrounding states—is thought to hold 262 trillion cubic feet of natural gas.
The U.S. has only just begun to harness that buried energy, but natural gas is already helping to curb oil imports. Odland said that while the U.S. used to import two-thirds of the oil it consumed, that rate has decreased to a little over 50 percent in recent years thanks to unconventional hydrocarbons. According to the IEA, oil imports could drop below 30 percent by 2035.
A greener alternative to coal. Natural gas is replacing coal in America's electric power plants. That's good for several reasons. For every unit of electricity produced, natural gas emits half the carbon emissions compared to coal.
Anthony Yuen, an energy strategist with Citi Research, told the audience that, against all odds, carbon emissions from power plants have actually declined by 15 percent since 2007 just from switching to natural gas. Natural gas also emits dramatically fewer air pollutants. "Even aside from the mercury emissions, the nitrogen oxide and sulfur dioxide and particulates are responsible for somewhere around 10,000 deaths in the U.S.," Meigs told the audience.
Job growth. Although employment was not a focus of the discussion, a report from the business analyst company IHS estimates that unconventional oil and natural gas will provide 2.5 million jobs in 2015 and 3.5 million by 2035.
Water quality. The controversial movie Gasland has a notorious segment in which a Colorado man lights his tap water on fire. It's a compelling scene, but contrary to the movie's suggestions, the cause has nothing to do with fracking.
However, while concerns over groundwater contamination by fracking may be exaggerated in this case—and most of the drilling occurs at levels far below water aquifers—there are a few cases in which fracking fluids are suspected to have entered groundwater, such as in the area of Pavillion, Wyoming. The EPA says there are no confirmed cases of contamination.
Higher prices. Unconventional hydrocarbons are more difficult and expensive to retrieve than the traditional stuff. While a typical barrel of OPEC oil has a break-even cost of $20, the same barrel would cost at least $50 if it were drilled offshore and $70 if it were extracted from oil sands. "It's the opposite of low-hanging fruit. We're now into the high-hanging fruit," Odland said. "We're moving down the efficiency curve, and up the price curve."
Competition with renewables. Because it's cheaper, natural gas has put a dent in the growth of wind and solar power, says Peter Kelemen, a Columbia University geologist.
Aesthetics. Oil extraction isn't pretty. And while that may seem somewhat trivial, environmental aesthetics can influence quality of life. "Ultimately, a lot of these questions won't be scientific questions," Meigs said. "They need to be informed by science, but they're ultimately political and aesthetic decisions. How many rigs do we want in the farms of Western New York?"
How will we treat the wastewater? Wastewater production has increased dramatically as a result of fracking in the Marcellus shale. Drilling companies use a pressurized fluid to fracture layers of shale and force out natural gas. The fluid is comprised mostly of water and sand, but in some cases toxic additives including benzene and lead are added to enhance recovery. Fracking can also pull radioactive uranium out of the ground in small quantities. Because it can take 7 million gallons of fluid to frack a single well, that adds up to a lot of wastewater and a lot of nasty chemicals.
Kelemen said wastewater treatment facilities can barely handle current volumes and will probably fall further behind—the industry is on track for a ten-fold increase in wastewater production over the next decade. Beyond the sheer volume, wastewater facilities are also ill-equipped to deal with several of the heavy metals and radionuclides in fracking fluid, Odland said.
Another option is to inject the fluid from whence it came—into very deep wells. But this option comes with its fair share of risks: As PM reported in April, wastewater injection is suspected to cause small- to moderate-sized earthquakes.
How much methane is released in the process? Methane, a potent greenhouse gas that traps 25 times more heat than CO2, escapes from natural gas wells in unknown quantities. Those methane leaks, which some activists say may be very large, could offset natural gas's role in cutting carbon dioxide emissions. Promisingly, a recent EPA reports that methane emissions from natural gas production dropped by more than 30 percent between 2007 and 2011.
Can fracking be safe but still profitable? Kelemen pointed out that there are a number of ‘best practice' wells that prove "this process can be done in a much more environmentally friendly way than it started out. And the only question we might have is, Are best practices profitable?"
Although so many unanswered questions remain, the industry continues to expand. Kelemen hopes scientists will continue to fill in the blanks, and that the government will do its job in protecting the people and the environment. "It's hard to underemphasize the essential role of an activist government in regulating this industry," he said.