It looks like these standards will do the following:
1) Impose fuel efficiency standards
2) Impose limits on GHGs from cars and trucks
3) Set a single standard for cars and light trucks, reaching 35.5 mpg by 2016.
Interesting. Usually global-warming advocates just go for efficiency standards and then expect those to be de facto limitations on GHGs. My first question is, what limits? Would it be a total cap on auto emissions every year, regardless of fleet size or total VMT/miles driven? Or would it be a per-vehicle-per-mile cap, a sort of emissions efficiency akin to fuel efficiency?
The point the article makes is that this announcement represented a deal: the automakers accepted aggressive efficiency standards, and a tighter deadline than the one imposed in the Energy bill of 2007 (2016 vs. 2020), and in return they get a single standard — no more different California standards.
The automakers would never have taken such a deal in the past — they would have dug in their heels and said no to any changes in the standard. But now, as they subsist on government support to get through the downturn, and without an important ally in John Dingell (who served as their watchdog for so long at the top of the House Energy and Commerce committee), they have a weaker position.
An additional playing card in Obama’s hand was that the Bush administration had refused California’s waiver request, and the Obama EPA is now considering whether or not to grant that request. California’s standards would have been similarly stringent, and automakers would have had to produce a significant “clean” fleet for that state.