OAKLAND, Calif. — California is making it mandatory for cars to be labeled with global warming scores, figures that take into account emissions from vehicle use and fuel production.

The law requiring the labels goes into effect at the start of next year for all 2009 model cars, though its expected the labels will be popping up on cars in the coming months.

The labeling law forces cars for sale to display a global warming score, on a scale of one to 10, which is based on how vehicles in the same model year compare to one another. The higher the score, the cleaner a car is. The score takes into account emissions related to production of fuel for each vehicle as well as the direct emissions from vehicles.

The score will be displayed next to the already-required smog score, which also rates cars one to 10 for how many smog-forming emissions they emit. For both scores, an average vehicle will have a score of five.

California is the first state of pass such as law, and a similar law will take effect in New York for 2010 model year vehicles. Global warming scores will be included on the state's DriveClean website.

While this law is intended to help consumers take into account emissions while purchasing cars, a proposed law in the European Union would require E.U. public sector bodies put a price on emissions.

A law endorsed by the European Parliament's Committee on Environment, Public Health and Food Safety would make governments put a monetary cost on the emissions of vehicles they plan to purchase, and add that to expense calculations. The law would exclude certain types of vehicles, such as ambulances and fire trucks.