Hill: Energy Secretary Ernest Moniz said the U.S. natural-gas boom is helping the nation battle climate change despite concerns about leakage of the potent greenhouse gas methane from well sites. His remarks show that although the Obama administration is studying methane questions, Moniz doesnt believe the emissions erode the climate advantage of natural gas compared to carbon-heavy coal it's displacing in power generation. My look at the evidence to date suggests that this in no way eliminates the...