WASHINGTON (CNN) -- Sen. Chris Dodd, D-Connecticut, is out with a new campaign ad Thursday that highlights his call for a corporate carbon tax to fight global warming.

The ad, set to air in Iowa and New Hampshire, features the Democratic presidential candidate in a classroom with young children as they sing, "the whole world is in our hands," and quickly transitions to a narrator stating "All the Earth's creatures are threatened by global warming."

"One candidate for president is doing something to stop it: Chris Dodd," the narrator continues. "He's the only one with an energy plan that has a courageous corporate carbon tax to transform American industry."

Described as a "moderate ad buy" by the campaign, this is Dodd's third presidential ad in a matter of weeks. The first two focused on his backing of a Senate bill that proposed to de-fund the Iraq war and directly challenged his Senate Democratic presidential rivals to do the same.