Methane emissions have been faliing while proposed regulations would be costly and have a negligible effect on temperatures

See Political Target: Natural Gas, a WSJ editorial. Excerpt

"Methane has long been a target of the green lobby because it is viewed as an especially potent contributor to global warming. Yet the EPA’s own research shows methane emissions from drilling have been declining rapidly.

The EPA’s Greenhouse Gas Inventory acknowledged this year that methane emissions from natural gas production have fallen 35% since 2007. That’s despite a 22% increase in gas production over the same period. The EPA last year found that methane emissions from hydraulically fractured gas wells had fallen 73% from 2011 to 2013. Overall methane emissions are 17% lower than in 1990. 

The industry has every incentive to capture methane emissions because it’s also a valuable energy source that can be used to produce electricity and heat. The more methane that drillers capture, the better the return on their investment. The industry has already unleashed an array of technologies to prevent leakage from drilling, transportation and processing, and innovation is improving those tools.

The new EPA rule will impose large new costs for little benefit. In 2013 methane emissions counted for about 9% of U.S. greenhouse gas emissions. Of that 9% about 3% are subject to the new rule, which would cut them in half. A Cato Institute study notes that even if the U.S. ceased all carbon emissions “now and forever,” the effect would be to reduce the rise in temperatures by the end of the century by 0.10 degrees Celcius. The methane rule’s contribution would be a mere 0.002 degrees Celsius."