The rules for vehicle gas mileage are pretty much locked down from now through 2025.
The math is complicated, but vehicles in 2025 will have to reach a fleet-wide average of 54.5 mpg by 2025--or about 42 mpg on their window stickers.
So what's the next battleground over reducing emissions?
Specifically, it's a set of proposed rules to limit emissions of carbon dioxide, a greenhouse gas, from future new powerplants--whether coal or natural-gas.
Coal plants would get a higher limit, but one that's significantly below what current plants acheive.
According to a report last month in The New York Times, to assist utilities in complying with the new limits, the EPA plans to revive a program to aid clean-energy development.
Revised rules are now being written, though the entire concept of the program will surely face intense opposition from a portion of Congress.
New rules face 'challenges'
As the newspaper notes in its usual genteel language, the new EPA limits on carbon-dioxide emissions from coal plants "will face political and legal challenges" before they become law.
Electric power plant outside Ithaca, New York
So look for the debate to break into public awareness at some point soon.
Expect to see a huge amount of advertising aimed at swaying public opinion on the issue.
Environmental groups and their allies will urge voters to support the new EPA rules, promising cleaner air and a real effort to reduce greenhouse-gas emissions.
Simultaneously, utilities and their allies will argue that the new rules will cost an enormous amount and threaten their ability to provide reliable, affordable electric service.
In fact, the electric utility industry faces challenges not only to its coal-fired plants but also, over the longer term, to its model of centralized generation and distribution of electricity.
An industry report suggests that the rise of dispersed generation from home solar panels and other renewable sources threatens its survival as currently structured.
The slow emergence of electric cars powered from the grid poses both challenges and opportunities to utilities.
How they react--and whether they can do so quickly enough in an industry used to amortizing assets over 50 years--will be fascinating to watch.
The future: less coal
The U.S. is unlikely to see any new coal-fired powerplants; the question may be more whether existing plants can economically be upgraded--or whether they should simply be closed.
The Tennessee Valley Authority is now converting 18 coal-fired generation units to natural gas; industry analyst Navigant Research calls this the "future of electricity generation" taking shape.
Meanwhile, brace yourself for a whole bunch of political ads trying to sway your opinion of the new regulations on coal-fired powerplants. You'll be asked to support abolishing, delaying, or modifying those rules.
Are you ready?