What do Al Gore, Rupert Murdoch, and the Rolling Stones have in common? They're all advocates of being "carbon neutral," the New Oxford American Dictionary's Word of the Year for 2006.

The phrase reflects the growing awareness of the importance of sustainability in the United States. It will be added to the next update of the dictionary, due in early 2007.

Erin McKean, editor in chief of the New Oxford American Dictionary, said, "The increasing use of the word carbon neutral reflects not just the greening of our culture, but the greening of our language. When you see first graders trying to make their classrooms carbon neutral, you know the word has become mainstream."