Natural gas (methane) has been hailed (even by some environmental groups) as a "bridge" fuel to a clean energy economy. Thanks to the development of high volume horizontal fracturing, commonly known as fracking, natural gas production is booming in the United States. Unlike the solar and wind industries, it is also popular amongst conservatives and is backed by the energy lobby. In that respect, transitioning from coal or oil to natural gas would be easier than transitioning to solar and wind power.
However, the perception that natural gas is a "clean" fuel is grossly misrepresented. The American Gas Association and other pro-gassers tout that natural gas combustion emits less carbon dioxide and sulfur dioxide than its other fossil fuel counterparts do. While these claims are true, they are also misleading because they fail to address the issue of methane leakage in the supply chain and at the consumer level. Seeing as methane is the second most prevalent anthropogenic greenhouse gas, and more than 100 times more potent than carbon dioxide in its atmospheric warming potential (adjusted for strength of impact over time), gas companies are omitting a significant portion of their contribution to climate change by neglecting to monitor or even mention methane leaks. Thus, most claims that transitioning to natural gas helps fight climate change should be taken with a heaping spoonful of salt.
The Energy Information Administration (EIA) reports that 27% of the 4.1 billion kWh of electricity generated in the United States in 2014 was sourced from natural gas, second only to coal, which occupied 39% of that share. Contrary to popular belief, if shale gas were to replace coal in the long term as the primary source of energy, climate change may actually be accelerated. One Cornell University study found that the greenhouse gas footprint of shale gas is 20% to 200% greater than that of coal over the course of 20 years (over 100 years, their GHG footprints were projected to be similar). In light of the upcoming UN Climate Change Conference in Paris, the United States (and other nations) should look to other sources of energy to avoid exceeding the 2Ã‚Â°C global warming "tipping point."
Moreover, EIA and industry projections on the supply of profitable and accessible natural gas reserves may in fact be overly optimistic, according to a recent article published in the Proceedings of the National Academy of Sciences. Currently, most models assume that all future wells will be at least as fruitful as the "sweet spots" that are currently being exploited. However, sampling the productivity of wells on a scale 20 times finer than that used by the EIA leads to very different results, producing a conclusion that natural gas production should decline rapidly in about a decade. In the words of Tad Patzek, lead researcher of the study and head of UT Austin's Department of Petroleum and Geosystems Engineering, "we're setting ourselves up for a major fiasco [by trying to extract and export as much shale gas as fast as possible]."
Those who advocate for natural gas as a bridge fuel are too optimistic about both its environmental and economic viability. Since 1880, the average surface temperature of the earth has warmed approximately 1.4 degrees Celsius. Climate change has already begun to affect us, as evidenced by the drought in California, Kutubdia's island refugees, and polar bear hybridization. If we don't want to overshoot the 2 degree Celsius tipping point and set off an irreversible chain of disastrous events, we need to take drastic and immediate measures to substantially cut our greenhouse gas emissions. Natural gas is not the answer to our problems for the same reason that diet soda wouldn't save a morbidly obese patient with type II diabetes and heart disease. Moreover, even if more resources were allocated towards minimizing methane emissions and new technology was developed to secure our supply of natural gas for decades to come, the warming potential of the greenhouse gas emissions produced under the natural gas scenario is at best unknown. When the stakes are as high as global food security, flooding of coastal cities, and a mass extinction event, as a society we ought to put our money behind the most surefire ways of avoiding disaster—natural gas is not one of them.