st week, investigators studying methane leakage levels in Manhattan reported alarming preliminary findings. The gas industry and Con Edison estimate 2.2% leakage in its distribution systems, and at leakage above 3.2%, according to the Environmental Defense Fund, natural gas ceases to have any climate advantage over other fossil fuels.
But the study found an average cumulative leakage of over 5% in natural gas production and delivery. At these levels, natural gas—93% of which is methane—has a far more potent greenhouse gas impact than burned coal or oil, the authors stated.
"The reports offer the most rigorous analysis of rate loss” to date, Al Appleton, former Commissioner of the NYC DEP, told Alternet, representing a "serious environmental reality.” The study was conducted by Gas Safety, Inc of Southborough, MA, for Damascus Citizens for Sustainability, an Upper Delaware Valley environmental organization that has been at the forefront of the anti-fracking activity in the Marcellus Shale.
When burned, methane natural gas produces CO2 but at half the level of burned coal or oil, a fact that has won natural gas the reputation as the cleanest fossil fuel. In the atmosphere, however, methane (CH4), the principal ingredient of natural gas, is a powerful greenhouse gas, like CO2 absorbing infrared radiation from the earth and warming the planet. Indeed by weight, and over time (100 years), methane warms 20 times more than carbon dioxide.