New Cars in California Must Display Global Warming Score

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.