California finally won its battle for permission to regulate climate changing auto emissions. The EPA granted a waiver allowing the state to proceed with its own plan. Washignton and 13 other states -- including Maryland -- have moved to follow suit.

Those states will start curbing emissions in the next year or two, and the rest of the country will join them in 2012 because of an agreement worked out among the federal and state governments, auto makers and environmentalists.

By 2016, everyone will be on the same page. The national miles per gallon average for cars and light trucks will be 35.5.

What will it mean? Environmentalist estimate that the limits will cut Maryland's global warming pollution by about the same amount as removing 4.5 million cars from the road for a year. Nationally, the standards are expected to reduce oil consumption by 1.8 billion barrels from 2012-2016 and reduce greenhouse gas emissions by 900 million metric tons.

Read the full story on the EPA's annoucement here.

Baltimore Sun file photo of Baltimore area traffic/Lloyd Fox