That second rule is more important for fighting climate change: Nobody is building new coal plants today anyway, because natural gas is so cheap. The nation’s almost 600 existing coal plants are the more pressing concern. Moreover, the approach the EPA is considering for those existing plants is more flexible and promising.
So the decision the EPA faces is whether to rewrite its proposed rule on new coal plants to make it less vulnerable to a legal challenge or to stick with its proposal.
If it were to set a looser emissions limit, equal to the lower emissions already being achieved by the most advanced coal-fired plants, it would quiet arguments that the relevant technology hasn’t been “adequately demonstrated.” But it would come at the price of higher emissions down the road, if the price gap between natural gas and coal narrows and companies start building coal plants again. Reworking the proposed rule also risks some delay in regulations for both new and existing plants.
It’s unclear whether the risk posed by the 2005 law merits a revision of the EPA’s proposed rule. Predictably, there are different opinions about the chances of a legal challenge. That’s a determination the agency will need to make, and carefully.
Whatever it decides, the EPA’s attention is best focused on the overall goal of the greatest possible reduction in emissions from all coal plants — both new and existing.