Where the US government fears to tread, the town of Boulder, Colorado, will dive right in.

On Tuesday, city residents will vote whether to adopt a ‘carbon tax’ to offset emissions from residences and businesses in Boulder. The cost? A mere $22 extra for the average resident per year. By 2012, Boulder wants its emissions to be 7 percent below its 1990 levels — itself following the Kyoto protocol the federal government has not yet signed.

Boulder is home to the University of Colorado, the National Center for Atmospheric Research, and with its highly-educated and affluent residents is a liberal haven. And if previous elections are any indication, Boulderites are ready to adopt almost anything: Several years ago, the city passed a law making people who own dogs not dog owners … but dog guardians.