Yale Econ. Professor Bill Nordhaus says pricing carbon emissions is "essential... to tackling global warming" and "the rest is largely fluff."

Ryan's got it right: we're not even considering the costs to our climate of our everyday decisions and yet they accumulate to make North Americans emit about 25 times as much carbon as the global average.  

A gradually-increasing revenue-neutral carbon tax would send the right signal.  It would change expectations and show us how to make efficient decisions about everything from where to live to what to wear.

Revenue-neutrality is very important-- last week NASA's lead climate scientist, Dr. James Hansen concurred with the consensus among economists: distribute the carbon tax revenues as a dividend to each household.  

That would be both effective to dampen global warming and economically progressive.  Imagine "stimulus checks" coming every month.  Yes, the prices of things would go up in proportion to their carbon content, but average and below-average income people would come out ahead.  And we'd all have the right price signals to get busy reducing fossil fuel use and switch to alternatives.

For more on revenue-neutral carbon tax and dividend, check out http://www.carbontax.org.