Is natural gas really a good alternative to coal to slow global warming?
Two major arguments justify a massive increase in natural gas production in the US. 1) It allows us to become energy independent, 2) It only produces half the greenhouse gasses of burning coal. The first argument has merit; the second argument is clearly open to debate.
What proponents of hydraulic fracturing (fracking) only consider is the actual burning of the natural gas to produce CO2. What they ignore is that methane, natural gas, is somewhere between 25-75 times as efficient as a global warming gas compared to CO2.
The reason that this is important is that we do not get 100% efficiency in the extraction, transportation, storage and consumption of natural gas---some is lost in each step of the process. In a peer-reviewed article in Climate Change Letters, Robert Howath, Renee Santoro and Tony Ingraffea have assessed the global warming footprint of fracked gas. What they report is that, “Our analysis of methane losses from the shale gas life cycle is based in part on a November 2010 report from the Environmental Protection Agency…and concludes that emissions---particularly for shale gas---are larger than previously believed.” Their paper indicates when you convert methane to its CO2 equivalent that fracking actually increases global warming compared to burning coal.
An October 2012 website article called, “Methane Emissions from Modern Gas Development,” the article states, “Petron et al., 2012, provided the first measured fluxes from an unconventional gas field---at the landscape scale and reported a “best estimate of 4%” (range of 2.3% to 7.7%) from production and processing streams.”
“Wigley (2011) uses climate modeling to assess the impact of transitioning to 50% natural gas power generation by 2050 over a range of emission scenarios (0% to 10%). For all emission scenarios, the switch to natural gas increases warming over the next 20 years. Recent climate modeling has marked these next 20 years as critical to climate mitigation."