Greenhouse Emissions Are Declining, But Don't Break Out the Party Hats

EPA data suggests America's greenhouse gas emissions are falling, but we have yet to solve some crucial pollution problems. REUTERS/Danny Moloshok

The emissions of greenhouse gases by American industry has declined 10 percent since 2010, according to data released today by the Environmental Protection Agency. That change comes as power plants increasingly choose natural gas over coal, the burning of which releases great quantities of carbon dioxide into the atmosphere. Environmental scientists almost unanimously agree that the carbon dioxide and other pollutants emitted by burning fossil fuels trap heat, leading to the so-called greenhouse effect that warms the Earth.

The EPA's Greenhouse Gas Reporting Program is a survey that "collects annual greenhouse gas information from over 8,000 facilities in the largest emitting industries, including power plants, oil and gas production and refining, iron and steel mills, and landfills," according to the agency's description of the program. The 2012 survey included self-reported data from 7,809 "direct emitters," 883 "suppliers of fuel and industrial gases" and 86 underground "carbon dioxide injection facilities."

The EPA first began collecting the data in 2010. According to a press release, the three-year 10 percent decrease "is due to a switch from coal to natural gas for electricity generation and a slight decrease in electricity production." The single-year decline from 2011 to 2012 was a more modest 4.5 percent.

Dale Jamieson, the Director of the Environmental Studies Program at New York University, says the drop may be "a temporary blip," but he is "encouraged" by the decline. He adds that "it's really good that we're getting this data," even if it's not clear how significant a change the 10 percent drop represents. (This data release is in keeping with President Obama's Climate Action Plan.)

The "direct emitters" cited above released 3.13 billion metric tons of carbon dioxide into the atmosphere in 2012. Among these, the most prominent polluters were 1,611 power plants, which accounted for 40% of all carbon pollution in the U.S.

Some cited the 10 percent drop as a cause for guarded optimism. Michael B. Gerrard, the director of the Center for Climate Change Law at Columbia Law School, calls the news "a positive," though he notes that "we've exported some of our emissions" to nations in the developing world. Last year, The New York Times published a report with a telling headline: "With China and India Ravenous for Energy, Coal's Future Seems Assured." The article noted that, based on research by Peabody Energy, "Global demand for coal is expected to grow to 8.9 billion tons by 2016 from 7.9 billion tons this year, with the bulk of new demand — about 700 million tons — coming from China."

Gerrard also says that the lingering after-effects of the economic downturn -- not any concerted shift in policy -- may have contributed to diminished electricity usage.

Dr. George A. Olah, a Nobel Prize-winning chemist at the University of Southern California who heads the Loker Hydrocarbon Research Institute, says "everything helps." He warns, however, that the switch to natural gas "isn't solving the essential problem" – that is, the release of pollutants like carbon dioxide, nitrous oxide and carbon monoxide. Data suggest that natural gas is cleaner than the burning of both oil and coal, but nevertheless releases these pollutants into the atmosphere.

Professor Gerrard also cautions that the extraction of natural gas via hydraulic fracturing -- fracking -- could cause methane to leak into the atmosphere. The process (which has fervent detractors and supporters) unlocks methane reserves deep beneath the earth's surface. However, a recent report from the Proceedings of the National Academy of Sciences suggested that fracking wells are often subject to leakage. As a subsequent article in Nature noted, "Significant leaks of heat-trapping methane from natural gas production sites would erase any climate advantage the fuel offers."

Detailed statistics on carbon emitters can be obtained online, at the EPA's Facility Level Information on GreenHouse gases Tool, or FLIGHT. An agency spokesperson did not respond to numerous requests from Newsweek for comment.