More than 3.3 million pounds of carbon dioxide was eliminated as a result of the Dave Matthews Band's 2007 summer tour through use of biodiesel and carbon offsets, according to data revealed by environmental nonprofit Reverb.

Portland, Maine-based Reverb, which works with acts to reduce their carbon footprint while touring, says one-third of the reduction is a result of fan participation. Though the nonprofit's Reverb Carbon Offset Program, DMB fans neutralized the carbon dioxide from more than 1.2 million miles of driving to and from shows.

"Dave Matthews Band has supported the environment long before environmental concerns hit the mainstream," Reverb co-founder Adam Gardner, who is also a member of rock act Guster, tells Billboard.biz. "Their efforts on tour have shown exactly how committed they are about making a difference."

Gardner says the DMB trek was the greenest tour of last summer, and possibly the greenest ever.

The 3.3 million pounds of reduction is equivalent to removing approximately 190 homes from the power grid for a year, according to Reverb. The tour's carbon footprint was calculated by Reverb, and then neutralized through NativeEnergy by supporting construction of new renewable energy projects.

The Dave Matthews Band will also partner with Reverb for its 2008 summer tour. Greening initiatives include an online carpooling service to shuttle fans to and from concerts, and an eco-footprint reduction contest that enables fans to track and minimize their environmental impact.