This post was co-authored by Alex Trembath, policy analyst at the Breakthrough Institute
For decades, natural gas was considered a highly attractive alternative to coal. It produced fewer greenhouse gas emissions, resulted in far less toxic pollution of landscapes and waterways, and could be a viable bridge to a zero-carbon future. Carl Pope, former Executive Director of the Sierra club, has long advocated natural gas as a bridge fuel to a low-carbon future. Al Gore has described natural gas as a “short- to medium-term bridge fuel, substituting for coal.” The Natural Resources Defense Council has written that switching from coal to natural gas can “diminish a number of public health threats caused by generating electricity.”
But as soon as the shift from coal to gas began, panic struck. The US shale revolution has made natural gas much cheaper in the United States, prompting a rapid shift from coal to gas in 2012, but also a proliferation of hydraulic fracturing (“fracking”) projects around the country to produce ample new gas resources. The spread of fracking has led to extreme backlashes in communities and among property owners who are concerned about the environmental and aesthetic impacts of the new industry. Green groups rapidly mobilized campaigns against fracking, alleging that natural gas is dirtier than coal, and insisting that America should transition instead to renewables like wind and solar.
Unfortunately, the economic and technological challenges facing renewables have proven them limited in their ability to significantly displace coal-fired power in most places. And according to a new Breakthrough Institute report, the original environmental wisdom about natural gas had it right. Natural gas offers sizable environmental benefits over coal along every metric, from landscape impacts and water intensity to toxic pollution and greenhouse emissions. By providing cheap, flexible power, natural gas will remain absolutely critical to intermittent renewables like solar and wind. And contrary to recent rounds of media commentary, uncertain regulatory regimes and high capital costs remain much bigger threats to US nuclear than cheap gas. Add everything up, and the economic benefits of the coal-to-gas shift (mostly in the form of lower energy bills) exceed $100 billion annually.
Public opposition to coal and pollution regulation have been mounting for years, but the real coal killer finally arrived in the form of cheaper, cleaner energy. Between 2000 and 2012, coal-fired electricity generation has declined by an average of nearly 40 terawatt-hours (TWh) each year, while gas has increased by an average of more than 50 TWh each year. Although other energy sources have grown as well (annual wind power generation, for instance, grew by an average of 11 TWh per year between 2000 and 2012), gas-fired power has proved the killer app when it comes to displacing coal.
Our report, titled “Coal Killer: How Natural Gas Fuels the Clean Energy Revolution,” details how the decline of coal in recent years has been an environmental blessing. Mountaintop removal obliterates ecosystems, destroys wildlife habitat, and creates serious downstream impacts. Underground mining results in waste materials being piled at the surface of the mine, creating runoff that pollutes and alters the flow of regional streams. Explosive blasting in mines causes groundwater to seep to lower-than-normal depths, contaminating aquifers. The numbers are clear. Lifecycle NOx, SOx, and mercury emissions from coal are 1.3, 18, and 27 times higher than those from natural gas, respectively. The amount of freshwater consumed for coal production and electricity generation is over twice the amount consumed by natural gas.
Coal’s decline has been an extremely beneficial development for human health. Coal combustion releases toxic chemicals including arsenic, mercury, lead, and numerous others. In addition to CO2, coal combustion also emits oxides of sulfur (mainly SO2), and oxides of nitrogen (NOx), which can cause adverse respiratory conditions. Hydrogen cyanide (HCN), sulfur nitrate (SNO3), and other toxic substances are also produced. SO2 reacts with atmospheric gases to produced sulfuric acid, which returns to the earth as acid rain, harming ecosystems and human health. Pollutant emissions from coal plants cause more than 20,000 heart attacks, nearly 10,000 hospitalizations, and more than 13,000 premature deaths annually in the United States.
As we document in our report, while natural gas is not without significant environmental challenges, these pale in comparison to the environmental threats posed by coal. Where coal exploration requires altering landscapes far beyond the area where the coal is, aboveground natural gas equipment takes up just one percent of the total surface land from where the gas will be extracted. Contamination of surface waterways and groundwater with natural gas hydraulic fracturing fluid is rare. The toxic emissions of pollutants like mercury, lead, and soot are far lower with natural gas than coal, and natural gas is much less water-intensive than coal mining and power production.
While natural gas production does pose serious environmental challenges, we believe that denouncing the shale gas revolution on environmental grounds is misguided. An expansion of natural gas can do more to reduce emissions and keep coal in the ground right now than any other energy technology, while acting as a platform for the development of zero-carbon energy technologies. America has proven that cheap gas truly is a coal killer, while emerging economies like China and India, and even uber-green Germany, have expanded coal production in recent years.
Natural gas has been killing coal in the United States, with enormous environmental and innovation benefits. The environmental community, in cooperation with the energy industry and federal regulators at the Environmental Protection Agency, has an obligation to facilitate, rather then block, the transition from coal to gas.