Methane leaks from shale gas fracking pose serious concern: study

Graphic from the film Gasland, a documentary about the environmental hazards of "fracking," depicted here in lower right.

A new study done by Cornell University ecologist Robert Howarth, the first comprehensive look at the environmental impact of shale gas extraction, finds that the process of extracting gas from shale by fracking is worse than burning coal, in terms of greenhouse gas emissions. The problem is that natural gas, which is mostly methane, leaks from wellheads and pipes, as well as from the ground after initial hydraulic fracturing takes place. While there is less CO2 in natural gas, the methane is just as serious a concern.

Robert Howarth of Cornell described the gas that escapes into the atmosphere at the time of the fracking as "very, very large flows [of gas]." As much as two percent of the total lifetime production of a gas well could be leaked, he continued,  "and given what a potent greenhouse gas methane is, that two per cent leakage is a big factor."

Hydraulic fracturing involves the injection of a mixture of water, sand and chemicals under high pressure to create cracks or fissures in shale rock formations deep underground. Howarth complains that the process has never been adequately studied for environmental consequences. Governments around the world have been doing a poor job of monitoring the leakage from wells, and there hasn't been any scientific research into the impact hydraulic fracturing may be having on groundwater or air quality.