Just a decade ago, clean energy champions talked almost exclusively of the familiar wind, solar, and biomass energy generation options. Since the hydraulic fracturing (fracking) boom just a few years ago, the clean energy debate has become a bit muddied. Beyond arguing that domestic natural gas production is good for energy and natural security, proponents of fracking and natural gas have been appealing to those concerned about climate change, arguing that natural gas is a “bridge fuel” to a lower carbon society.
But skeptics of this line of reasoning are numerous. A new report in the Proceedings of the National Academy of Sciences reveals that fugitive (uncaptured or accidental) natural gas emissions from fuel extraction and processing are much higher than previously thought, bolstering natural gas skepticism.
For a bit of background, U.S. greenhouse gas emissions consist primarily (84% as of 2011) of carbon dioxide (CO2). Methane and Nitrous Oxide (yes, laughing gas) make up the majority of the remainder contributing 9% and 5% to total emissions respectively. Used as a substitute for gasoline and diesel, compressed natural gas primarily consisting of methane has lower greenhouse gas emissions and much lower CO2 emissions in particular. Moreover, electricity generation from natural gas can be run either to cover base load demand or with variable output, a key characteristic to be compatible with intermittent electricity sources like wind, solar, and other renewable energy generation methods.
As a result, even MIT’s Energy Initiative center and our now Secretary of Energy advocated the natural gas was a low-carbon alternative that should be pursued to bridge the country toward renewable energy and to slow global warming.
But low-carbon energy is misleading. When it comes to climate change, a gas’s warming potential is of key importance. Using a relative scale, CO2 has a global warming potential of 1 and all other gasses are compared to CO2’s ability to trap heat and warm the planet. Methane – the primary component of natural gas – has 25 times the warming potential of CO2. In other words, not fully combusted, natural gas is worse for climate change.
The new report, demonstrating that methane emissions are actually higher than previously thought, calls to question where the “bridge” built by natural gas is actually leading us. Though the EPA recently decided to cut its estimates of these fugitive emissions, the report argues that these emissions are actually 2-8 times higher than the EPA originally estimated. Many of these emissions come from fuel extraction, including natural gas drilling and fracking.
Moreover, other articles have argued that an increase in natural gas use hasn’t really been seen as connected to more renewable energy. Renewables only account for around 8% of total energy consumption in recent years, most of which comes from large hydropower which is not new nor considered renewable by many environmental organizations.
As a nation, we need to find alternatives to fossil fuels. In the West, this means focusing less on natural gas plant development; elsewhere, it means less coal. The debate over clean energy shouldn’t be muddied with half-truths about natural gas. It’s still a fossil fuel, it’s still non-renewable, and under current regulations and practices, it could be much worse for climate change even if it can claim to be low carbon. Instead, the U.S. should start focusing on investing more in renewable technologies and giving nuclear options a closer look.
**This blog is abridged from its original, posted on Minnesota 2020 (http://mn2020hindsight.org/view/natural-gas-a-bridge-fuel-to-faster-climate-change)