Clearing the air with natural gas

It’s time to recognize the most important benefit of the shale-gas revolution … cleaner air! Expanding the production of natural gas offers the potential to dramatically reduce greenhouse-gas emissions not only in the United States, but globally.

Ten years ago, that idea would have seemed absurd. The U.S. supply of natural gas then was stretched tight. But in recent years a combination of horizontal drilling and multi-stage stimulation – the injection of sand, water and additives under high pressure deep underground – has been used with great success to unlock natural gas trapped in shale formations like those that underlie large parts of Ohio, Pennsylvania, North Dakota, and Texas. As a result of this great technological innovation, U.S. natural gas production has increased by as much as 25 percent, and America has eclipsed Russia as the world’s number one producer of natural gas.

For anyone concerned about climate change, that’s something to crow about. Natural gas has an inherent environmental advantage over coal. When used for electricity production, it produces 60 percent less carbon dioxide emissions than coal. According to the International Energy Agency, the shift from coal to gas in the United States is the primary reason why carbon emissions have dropped to 1990s levels in the U.S., while supplying the energy needed to fuel economic growth. In fact, the United States has now taken the global lead in curbing emissions.

Other countries with large shale-gas resources are likely to follow the U.S. lead in developing them. China has the world’s largest shale-gas reserves, more than the United States and Canada combined. Russia, Poland, Australia, and France aren’t far behind.

Regrettably, most U.S. environmental groups oppose the greater use of natural gas despite its environmental benefits. In their view, the production and burning of all fossil fuels is bad for the planet. They prefer renewable energy sources, which are emission-free. But even with the help of state mandates for renewables and subsidies, solar and wind combined account for only 4 percent of the U.S. electricity supply. By contrast, natural gas provides more than 30 percent of the nation’s power, and its share is rising.

Shale gas is not the only solution to climate change. Nuclear power has a critically important role to play, especially since it’s a zero-carbon fuel source and produces a large amount of energy 24/7 regardless of whether the sun is shining or the wind is blowing. Clean coal technology is also important in the energy equation, since America is blessed with some of the largest coal reserves in the world.

Though estimates of the amount of natural gas vary, America’s supply is currently projected to last more than 100 years. At present, we’re producing more gas than we need or can use. Consequently, much of the gas associated with oil production in the Bakken shale in North Dakota is being flared out of necessity. Natural gas is primarily composed of methane, a particularly powerful greenhouse gas. Simply venting the gas would act to accelerate climate change.

Smaller volumes of methane are also released all along the natural gas supply chain. Curbing methane emissions is now a high priority of the natural gas industry and federal and state regulators. In this regard, Colorado has taken the lead, adopting the first rules anywhere that directly regulate methane emissions. Ohio has also followed suit with new regulations requiring vapor recovery systems on all tank batteries used to collect oil and condensate from producing wells. The goal is to reduce methane emissions virtually to zero.

Working to realize the full potential of natural gas in powering the future in tandem with renewable energy sources, clean coal technology, and nuclear power, along with improvements in energy efficiency, offers a significant opportunity for the planet.

It’s time for environmental groups and the gas industry to work together and embrace the use of shale-gas technologies that are cost-effective and can make a contribution to winning the battle against climate change.

Robert W. Chase is chair and benedum professor of Marietta College’s Department of Petroleum Engineering and Geology, 215 Fifth St., Marietta.