Natural Gas and Climate Change: A Bridge to Nowhere

Page - June 7, 2012
For years the gas industry has advertised “clean, reliable natural gas” as a boon for the environment and a viable alternative to coal when it comes to reducing greenhouse gases from the generation of electricity. The claims are based on the fact that natural gas is mainly methane, which burns cleaner than oil or coal, releasing less CO2 per watt of energy than other fossil fuels. However, recent studies comparing the entire fuel cycles of gas and coal conclude that gas is just as bad, and may even be worse than coal when it comes to total Green House Gas (GHG) emissions.

Though it releases less carbon than other fossil fuels when burned, methane itself is a powerful greenhouse gas, 105 times more potent that CO2 over a 20 year time horizon. When a well is fracked, significant amounts of methane can be released into the air during the production stage – through leaks, venting, and flaring. Furthermore, methane escapes throughout the natural gas lifecycle, which includes storage and transportation.
 
It is currently an accepted industry practice for raw methane to be purposefully released into the atmosphere.  To keep pressure from building up inside the well bore after a well is fracked, drillers will sometimes vent or discharge some of the gas.  This process is called “burping” the well.

Because of the relatively low price of gas and the high price of oil, which is also accessed using the fracking process, some drillers find it easier to vent or flare the methane into the atmosphere rather than capture it. This allows them to extract the oil more quickly.

Also, methane leaks from storage tanks and pipelines meant to contain it.  These pipelines and storage facilities are not regulated by Pipeline and Hazardous Materials Safety Administration (PHMSA), meaning they're not regularly inspected for leaks or corrosion. Attempts by EPA to regulate these pipelines have been limited and delayed, leading not only to leakage, but to explosions and deaths.

Further Reading:
Howarth RW, Santoro R, and Ingraffea A, “Venting and leaking of methane from shale gas development: Response to Cathles et al. Climatic Change,” (2012, in press)

Robert Howarth et al., “Methane Emissions from Natural Gas Systems,” Background Paper for the National Climate Assessment, 2/25/12, 

N P Myhrvold and K Caldeira, “Greenhouse gases, climate change and the transition from coal to low-carbon electricity,” Environmental Research Letters, 2012. 

DeSmogBlog, “Fracking the Future

Caroll Linnitt, “Post Carbon Institute Debunks False Hope Of Gas As ‘Bridge Fuel’ ” DeSmogBlog, 6/11/2011