As I wrote here, the recent major drop in U.S. CO2 emissions - thanks in part to cheap natural gas made available by the shale boom displacing coal as the fuel of choice for electricity generation - was likely temporary.
As Jesse Jenkins writes today for theenergycollective, gas prices are rebounding, and as a consequence, so is coal consumption. U.S. carbon emissions - and that of other harmful air pollutants - will go back up.
Just as the U.S. climate gains went up in smoke on a global level as the U.S. exported cheap coal to Europe and Asia, the recent U.S. carbon gains were temporary - and illusory - when they need to be large and permanent.
If the U.S. is to lower its greenhouse gas emissions, abundant shale gas is hardly enough. We'll need more than a reliance on commodity prices and short-sighted self-congratulation. We need an aggressive, comprehensive energy policy.