Bryan Walsh at Time accurately points out this morning that the big winner in today’s EPA rules capping carbon emissions from power plants is natural gas. Coal has been on the way out with only one new coal plant, which has carbon capture technology, being built during the Obama administration. The new rules limit CO2 emissions for power plants to no more than 1000 lbs of CO2 per megawatt hour produced (coal averages around 1800 lbs, way outside that limit). Natural gas typically comes in at a bit under the 1000 lb limit. And so, in line with Obama’s endorsement of natural gas during his state of the union speech in January, the U.S. goes down the road of a slightly less greenhouse gas emitting power source. As my weekly update points out, the price of natural gas is just so low that it carries the risk of slowing investment in renewables. Which is why as much as everyone hates regulation, the only way to truly push power generation towards low CO2 emissions is to tax carbon. And the only way to do that is to get people to understand that, much like cigarettes have costs to our health care system far beyond what smokers pay at the register, carbon emissions cost everyone a lot more than the spot price for natural gas.