Plans to expand the production of natural gas from shale formations in the United States and around the world may face an as-yet-unseen stumbling block.
Atmospheric scientists are concerned that even small amounts of methane leakage from the production and use of natural gas could negate whatever environmental gains have been made in reducing America's carbon footprint from the much-publicized switch from coal to gas in electricity production.
Due largely to the expanded use of natural gas, which has roughly half the carbon content of coal, U.S. carbon emissions are at their lowest level in 20 years. But that's no reason to celebrate. Whatever environmental gains have been made are likely to vanish in the years ahead.
Nor is there any reason to celebrate the impending loss of Vermont Yankee, a safe and efficient nuclear plant which provides a large amount of electricity reliably for homes and businesses without polluting the air or emitting greenhouse gases. In time, we may come to regret the shutdown of Vermont Yankee, and the increasing reliance on natural gas for electricity production in New England.
Scientists say that methane is much more effective at trapping heat than carbon dioxide, and its emissions are raising legitimate questions about whether shale-gas production might be hurting rather than helping the fight against climate change.
A global warming gas, methane is 72 times more potent than carbon dioxide during the first 20 years after it is released.
While it's not known precisely how much methane is being released -- estimates range from 2 to 11.7 percent of natural gas production, even a small amount of methane emitted to the atmosphere, as little as 1 percent or less, can undo some or all of the benefits we get when we substitute natural gas for coal.
Recognizing the problem, earlier this year the White House released a national methane reduction strategy as part of President Obama's climate action plan. But the fossil fuel industries have been slow to respond. Right now, we need to be moving forward with deliberate speed to cut methane emissions.
A good start would be to stop the flaring of natural gas. Although the strong economic benefits of the shale revolution have brought renewed hope and opportunity to many areas of the country that were once written off, a large amount of natural gas is being produced as a byproduct of oil in places like North Dakota where there are no pipelines. As a result, natural gas, whose main component is methane, is often purposely vented or flared into the atmosphere, because there is no way to ship it economically to where it can be put to use.
Last year, producers flared enough natural gas to have produced almost 30 million megawatt-hours of electricity, according to the Energy Information Administration. That raised emissions by more than 16 million tons, about 15 percent as much as the reduction in coal burning saved.
Consequently, methane has become a major obstacle to climate action. Because methane is released from thousands of different sources -- leaks from fracking and other activities surrounding gas production as well as leaks from aging cast-iron pipes that run beneath the streets of U.S. cities -- regulatory action is required.
Although the loss of natural gas is bad for the environment and a waste of a natural resource, Colorado is the only state to have issued rules for controlling methane emissions. Colorado requires gas producers to reduce emissions by 100,000 tons a year, something that would make shale-gas development safer. But the natural gas industry -- there are over 2,000 natural gas producers in the United States -- opposes regulation, and the Environmental Protection Agency has yet to decide whether it will regulate methane emissions.
Given the potential for climate-destabilizing emissions, what should be done about it?
There is a straightforward answer. Nuclear power is emission-free. The United States gets about 20 percent of its electricity from nuclear power. Reactors provide power around the clock, without polluting the air or releasing global warming gases. Its wider use in the United States and around the world, along with improvements in energy efficiency and expanded use of solar and wind power, could dramatically reduce emissions over the long term and help prevent the worst effects of climate change.
Bob N. Leach is a retired radiation protection manager and certified senior reactor operator. He lives in Brattleboro.