Releasing a rare bit of optimistic news in the fight against climate change, the United States Environmental Protection Agency said Friday that automotive carbon emissions are down.

They declined nearly 7 percent on average for the 2012 model year compared with the year before, the agency said. That's more than 3 percent lower than the 2012 federal standard.

“The report reveals that consumers bought cleaner vehicles in the first year of the program than the 2012 [greenhouse gas] standard required, and that automakers are off to a good start in meeting program requirements,” the EPA said in a statement.

Well, sort of.

It’s not quite as straightforward as that. As part of a 16-year program to slash vehicle greenhouse emissions that began in 2012, the EPA allowed automakers to initially offset their carbon spew by accumulating and trading various credits, earned for doing things like improving the efficiency of air conditioning systems to prevent the leakage of potent greenhouse gases.

When those credits are considered, all automakers emerge winners.

But looking at the raw numbers, nine manufacturers fell short: Nissan, Volkswagen, BMW, Chrysler, Volvo, Mercedes, Suzuki, Jaguar Land Rover and Ferrari. Those companies sold a total of 4 million cars in the United States in 2012. On the plus side, the automakers in compliance with the greenhouse gas standards—including General Motors, Honda and Toyota—produced 8.3 million cars.