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.