1. To truly be a "bridge fuel" that is less creative of climate change than coal as an electric power plant fuel, total leakage from natural gas production must be under 3 percent or so, due to methane's own greenhouse gas effect.
2. In Utah's natural gas fields, currently under intense development, that leakage is reportedly as high as 9 percent.
Go read the full story for more about leakage rates, measurement issues and more. That includes a link to a study that says the leakage is worse from fracked gas wells. Here's the level of the problem:
Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.Not close to a "bridge fuel" in that case.