Over at Slate, freelance writer Brian Palmer asks and answers the question: How far do you have to commute by bike to cancel out the carbon emissions produced in the manufacturing of your bicycle?

Palmer's answer: Around 400 miles should erase the bad environmental karma of the 530 pounds of CO2 emissions that go into making the typical bike.

Given my eight-mile round-trip commute from home to work, it took me 10 work weeks to break even on carbon.