The big news today is that President Obama has announced two new sets of rules -- to be administered by the Department of Transportation and the Environmental Protection Agency -- governing cars and greenhouse gas emissions:
(1) New standards for greenhouse gas emissions from car tailpipes. The Post describes these as the "first nationwide regulation of greenhouse gases."
(2) An increase in fuel efficiency targets to 35.5 miles per gallon for new passenger vehicles and light trucks by 2016, four years earlier than required under the 2007 energy bill.
As I understand it, the current requirement for passenger vehicles is 27.5 miles per gallon.
The political breakthrough is that all the major automakers signed on to the new standards. California had requested a waiver to impose tougher standards in 2008 (13 other states also wanted to do so), and the Bush Administration had refused the request. What a difference a year makes -- in terms of environmental effect, I'd have to imagine this is the most significant change in federal law in years.