Environmentalists are not enthused about the prospects of meaningful climate legislation for the rest of President Obama’s first term. They may be able to eke out some legislation on oil spill response, a weak renewable energy standard (though Lindsey Graham’s introduction of nuclear power into that debate puts that in peril) and some renewables and energy efficiency tax incentives, but in the main you’re not going to see much of anything out of Congress that would really bring down carbon concentration in the air.

That effort moves to the regulatory agencies now. The EPA already plans to regulate greenhouse gas emissions, which could lead to retiring many old coal-fired power plants. And now, they are teaming with the Department of Transportation to deliver new rules on fuel economy that could reach pretty sharply high levels:

The Obama administration on Friday is expected to suggest nearly doubling fuel economy goals for new cars and light trucks — possibly to more than 60 miles per gallon by 2025.

Under orders from the White House, the Environmental Protection Agency and Transportation Department have been working for several months on the next phase of gas mileage standards for motor vehicles built between 2017 and 2025.

Auto industry and environmental sources say the agencies will suggest rules improving fuel economy between 3 percent and 6 percent per year. Environmental groups are urging the administration to ultimately set the annual increase at 6 percent, which would force the national fleet average beyond 60 miles per gallon in 15 years.

A 3 percent annual increase would hit around 46 mpg by 2025.

While this sounds very high, it’s not unfathomable. Cars in Europe and Asia have a far higher fuel efficiency than they do in the US. And if electric vehicles and other non-gasoline options get a boost in legislation which may pass after the elections (although it’s worth being wary about the Pickens Plan part of the deal), you could totally see this becoming realistic.

The EPA took the first step on this today with a notice of intent. They evaluated scenarios for a 3%, 4%, 5% and 6% increase, so they’re keeping everyone guessing. However, it does appear that future fuel economy standards will be going up substantially in the coming years.