"We started doing shows in 1998. You look around, and you realize that there are trucks and buses and the tour has a pretty large carbon footprint. So we started running our buses on biodiesel and working to buy offsets. With this year's tour, we're bringing in nonprofits. We'll see if we can up their membership or give away tickets so they can raise money. We match our audience contributions dollar for dollar, up to $2,500 per charity."