Amy Standen specializes in science and environmental reporting for Quest. She’s among the guests today on KQED’s Forum program. Listen to the archived program here.

Yesterday afternoon, as I started working on my news spot about the new federal standard for tailpipe emissions, I dug up my notes from over a year ago, the last time I covered this story in any depth.

The contrast in tone between then and now amazed me. Back then, I was describing accusations of outright lying, government actions that California enviros called “completely illegal,” and California officials “sharpening their knives” as they marched into battle with EPA former Administrator Stephen Johnson. It was September, 2007, and Democratic lawmakers, led by Henry Waxman (D-CA), were accusing the White House of strong-arming the EPA into denying California its “waiver,” or permission to regulate auto tailpipe emissions. The mood between California environmentalists, many of the state’s elected officials, and the Bush administration couldn’t have been more hostile.

Today, it’s as if we’ve landed in an alternate reality.  Not only has California been given its more fuel-efficient cars, but those same laws are taking effect nationwide. The new rules actually exceed anything that California–traditionally the most ambitious state in the union, when it comes to greenhouse gas regulation–could have asked for.

Instead of knives being sharpened, California enviros are singing the praises of “an historic blueprint to carry out rigorous greenhouse gas emission standards,” to quote one email I received today. Another group told the New York Times: “This is the single biggest step the American government has ever taken to cut greenhouse gas emissions.” Compared to the fall of ’07–actually make that since ’05, when California first asked for the waiver and the EPA first started stalling–it’s like night and day.

Still, listening in to the White House background press briefing on Monday afternoon, you could hear the seeds of criticism taking root in a few reporters’ questions.

Sure, American automakers will be making more fuel-efficient cars, one reporter asked, but what is the White House doing to encourage consumers to buy them? (in addition to restricting tailpipe emissions, the new rules also substantially increase fuel efficiency standards for manufacturers’ fleets–SUVs and trucks will still be available; they’ll be more fuel efficient than before, but less efficient than smaller cars.) The question takes on new relevance as the federal government finds itself a major stockholder in auto companies.

President Obama says the new regs will have the equivalent impact of taking 177 million cars off the road.