My Clean Break column today looks at the role that natural gas will play as we move toward lower-carbon sources of energy, but it also warns of relying too much on shale gas. Here’s the issue: shale gas is not just a water pig and a potential threat to water aquifers and lakes, it is extracted in a way that may release more greenouse-gas emissions than we bargained for. Sure, burn it in a power plant and, just like conventional natural gas, it emits as much as half the emissions of a coal-fired power plant. But fugitive methane emissions released during the extraction of shale gas could make this supposedly lower-carbon source of energy a much dirtier option that coal. I say “could” because we don’t know for sure — there isn’t enough information and there hasn’t been enough study of this issue to know for certain. Given this uncertainty, is it wise to call for a major transition to natural gas from coal — as some folks at MIT have suggested — as a way to lower greenouse-gas emissions in the short term? Is it wise for the U.S. to drop plans for a comprehensive climate bill in exchange for a narrow energy bill that would boost natural gas demand but do nothing for renewables? On the surface, it sounds like a winning strategy. I just worry that, when the full lifecycle analysis is done, we’d just be making things worse if such a transition relies on new shale gas development. Check out my column for more details.