Natural gas and nuclear have done more than any other fuel source to displace coal, and have saved the United States 54 billion tonnes of carbon dioxide emissions since 1950. In the past five years, natural gas alone has displaced coal and driven the country’s power sector emissions down 20 percent, leading to immense environmental and human health benefits. What follows is a response to Mark Bittman’s dreary diagnosis of natural gas.
Gas is killing coal across the country. In the last five years, coal’s share of electricity has declined from 50 to 38 percent, while gas’ share has increased from 22 to 30 percent. This shift has culminated in a massive nationwide reduction in carbon dioxide emissions and enormous environmental and health benefits. As we document in a recent report, coal is far worse than gas on virtually every health and environmental metric; it leads to many more deaths, pollutant emissions, and much greater ecosystem impacts than gas. The wide-ranging benefits of gas’ assault on coal should be celebrated, not obfuscated.
Gas is a bridge fuel to zero-carbon energy if we want it to be. Studies that actually model natural gas as a bridge fuel find natural gas could help stabilize atmospheric carbon dioxide concentrations and play a significant role in limiting the atmospheric carbon dioxide concentration to 550 parts per million, provided that zero-carbon energy sources such as nuclear power, carbon capture-equipped gas plants, and renewables are simultaneously deployed.
Claiming that our situation is too dire for bridge fuels, Bittman cites a Climate Progress article that relies on an International Energy Agency (IEA) special report titled “Are we entering a golden age in gas?” The report, however, fails to model a gas-bridge scenario, instead only showing what would happen if natural gas increased and growth in zero-carbon energy remained at business-as-usual levels. By definition, if gas was employed as a bridge fuel it would not be expected to stabilize atmospheric concentrations of carbon dioxide single-handedly, but would be simultaneously deployed with other forms of low-carbon energy.
Renewables need gas. One of natural gas’ most important strengths as a bridge technology is its ability to support the continued expansion and deployment of wind, solar, and other zero-carbon energy. By providing backup and firming capacity, the expansion of gas-fired power plants can accelerate the integration of intermittent power into existing electricity grids. Bittman concludes by calling for a “huge push to real renewables” and suggests “[dismantling] the existing infrastructure, starting with coal and nuclear,” but this is tantamount to destroying the very infrastructure wind and solar need.
Gas is a historic driver of emissions reductions. Since 1950, two energy sources – nuclear power and natural gas – have dramatically reduced the carbon intensity of our economy. Had the energy from these two sources been supplied with dirtier coal, there would be an additional 54 billion tonnes of carbon dioxide in the atmosphere today. By contrast, in 2012, the entire world’s energy sector emitted 35 billion tonnes of carbon dioxide. This is 36 times more carbon dioxide displacement than that achieved by all non-hydro renewables. Rather than obsess over methane leakage rates, we should celebrate these gains.
Consensus shows 2 percent or less methane leakage. By relying on a few sources, including a dubious study by researchers at Cornell University, and invoking anecdotal evidence, Bittman obscures a wider consensus of studies that show that methane leakage from shale gas development is around 2 percent or less, thereby giving it a significant climate advantage over coal. The latest data from the US Environmental Protection Agency’s Greenhouse Gas inventory pegs fugitive methane emissions at 1.5 percent of total production, and estimates that methane leakage is on the decline. The most comprehensive study of methane leakage from shale gas to date, published last week, estimates a 0.42 percent leakage rate for shale gas production.
High-impact, low-cost intervention could contain “super-emitters.” Rather than being an argument against the climate benefit of natural gas, as Bittman uses it, the existence of a small group of “super-emitters” suggests that methane leakage is not a diffuse issue, but one that could be isolated and addressed in a low-cost manner.
With gas, it pays to prevent emissions. Even without regulation, the likelihood of intervention is high because there are large financial incentives for developers to limit emissions from their wells. As the president of development of Southwestern Energy said to Bittman, it is cost-effective for developers to minimize fugitive emissions, since all methane leakage is money lost to gas producers.
There will also be a rapid shift in the wake of EPA’s natural gas emission standards, which will roll out in 2015 and require all gas developers to install technologies on wells to reduce their emissions by 95 percent or more. EPA’s emissions standards are expected to lead to 1.7 million tons of methane savings annually – the equivalent of removing 4 to 8 million cars from the road each year from a GHG emissions standpoint.
Energy transitions take time, and do not occur by dismantling current systems. Bittman’s casual dismissal of natural gas and nuclear power reveal his lack of understanding about how energy systems change. The US energy system has been changing gradually for hundreds of years, getting cleaner and more diverse through time. Rarely have energy systems undergone a “dismantling of the existing infrastructure,” instead evolving through time through social, economic, and technological forces. Gas abets, not hinders, this necessary evolution toward cleaner sources of energy.