Appropriate and useful climate policy-making requires accurate and reliable data about the future.  Nowhere is this more important than when setting carbon emission standards and projecting percentages of each energy source to match energy needs (coal, natural gas, nuclear, renewables, etc.).  But projecting how emissions will change in the decades to come, say to meet the 2030 standards, is a tricky business.  In particular, natural gas has been touted as a ‘bridge’ to a low-carbon future with predictions that it would take over a share of energy production from coal and thereby reduce net emissions (natural gas has about a fourth of the greenhouse potential of coal, if you take away methane leaks in transportation pipes).

But is this really true?  Does the data back this up?  These are the key questions policymakers must know the answer to when deciding whether to promote natural gas expansion with subsidies, etc.  And it falls…