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 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, up to 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.

Recent Emmissions Studies

Recent studies have raised alarms bout methane leakage from fracking wells. A 2012 study from Utah found that between 6 percent and 12 percent of the Uinta Basin's natural gas production could be escaping into the atmosphere. The study found that the basin's 6,000 wells leaked 60 tons of natural gas an hour during the a Feb. 3 2012 testing window.

A similar study from the Marcellus shale in Pennsylvania conducted in 2014 found methane levels 100-1000 times EPA estimates. 

Studies from Colorado have corroborated the high emmission levels from fracking found in other parts of the country. During two days of intensive airborne measurements, oil and gas operations in Colorado’s Front Range leaked nearly three times as much methane, a greenhouse gas, as predicted based on inventory estimates, and seven times as much benzene, a regulated air toxic. Emissions of other chemicals that contribute to summertime ozone pollution were about twice as high as estimates, according to the new paper, accepted for publication in the American Geophysical Union’s Journal of Geophysical Research: Atmospheres.

Green Completion

Green completion rules have been passed on a federal level. These rules require technology to reduce flaring and venting from fracking wells, to be enforced in 2015. However these rules exempt fracking wells targeting oil, the vast majority of new fracking wells.

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