Today the federal Environmental Protection Agency formally granted the waiver that California has sought since 2002, allowing the state to set its own standards for greenhouse gas emissions from cars.

But wait–didn’t this already happen for practical purposes, last month? That’s when the Obama administration announced its intent to essentially put California’s proposed standards in place nationwide.

Well, yes–and no. Bernadette Del Chiaro, who represents the group Environment California, says that having the waiver is more than a legal technicality. She says it means that the state can get started sooner, cleaning up tailpipe emissions. Del Chiaro explains that: “California’s standards kick in now, through 2016. The federal program that President Obama has extended throughout the entire country, starts in 2013 (also through 2016).”

That gives the states, in effect, a three-year jump-start. In 2013, everybody should be on the same page.

California’s chief air regulator,  Mary Nichols said, in a written statement:
“The waiver affirms California’s authority to set the standards for the cleanest cars in the nation and recognizes the ability of forward-thinking states to continue to adopt them. Now we can begin to work with the manufacturers to make a new generation of cars that deliver all the comfort and power we have come to expect but with improved efficiency and far fewer greenhouse gas emissions. ”

Thirteen other states had also pursued the waiver and can now proceed with their own programs.

While automakers have long argued that the tighter regs will make cars more expensive, Environment California calculates that they’ll “save consumers $36 billion at the pump by 2020.” That projection assumed that gasoline would would average about $2 per gallon over that period. Higher pump prices (which seem a lot more likely) would in turn, increase expected savings, as the underlying premise is that we’ll be driving cars that get better gas mileage.

But of course those cars will cost more than the clunkers we’re wheeling around in now. The state Air Resources Board estimates that the clean car regulations will tack an average of $1,000 onto the price of a new car by 2016. Obviously that would offset some of the pump savings.