These down-to-earth rockers made headlines during their tour last year when they donated a total of $100,000 to nine organizations working on climate change, renewable energy, and other green causes. On their previous tour, the band donated funds to help preserve Madagascan rainforest. But looking in the rearview mirror, these grunge gods have always been committed to eco-causes from staging benefit concerts to busing with biodiesel.

KT Tunstall

Grammy-nominated singer-songwriter KT Tunstall may have her Eye to the Telescope (suddenly, she sees!), but she's also got her finger on the pulse of green goings-on. Tunstall ran her tour bus last fall on a biodiesel blend and plans to make her future eco-commitment even more drastic (fantastic!). Tunstall's affiliation with The CarbonNeutral Company has enabled her and her fans to plant some 5,000 trees as offsets. She has also backed a "carbon diet" campaign by Global Cool, a group that brings entertainers and scientists together to fight global warming.

Green Day

Though eco-issues weren't the inspiration for this pop-punk trio's name, these guys are no American idiots when it comes to being green. They've partnered with the Natural Resources Defense Council on a Move America Beyond Oil campaign, and have made a number of YouTube videos voicing support for environmental protection and smarter energy policies.

The Roots

This Grammy-winning hip-hop group certainly has strong roots in the environmental movement. As well as being fond of Organix, the band members are animal lovers, working with PETA on a campaign to "Stop the Violence: Go Veg." The group also hosted a Pre-Grammy Jam & Green Carpet Bash this year, inviting fellow artists and friends to jam with them and raise awareness about green issues. As part of that event, they partnered with youth-focused green group Global Inheritance to promote composting by giving away specially designed and autographed compost bins.

Radiohead

This Radiohead frontman and, more recently, solo artist is a longtime vegan who has played a prominent role in Friends of the Earth's Big Ask campaign, pushing the U.K. to adopt a strong law to fight global warming. Yorke says his solo album The Eraser was inspired by the climate crisis.

Moby

This DJ-turned-pop-star's entire musical style is about recycling -- repurposing beats and riffs from other artists into tracks of his own. But Moby is much more deeply invested in green principles: After releasing a "best of" collection last fall, he decided to limit his touring to cut down on his environmental impact. A vegan, he's a big supporter of PETA and the Humane Society, and in 2002 he opened Teany, a vegetarian tea café in New York City.

Cloud Cult

This up-and-coming band out of Minnesota is unabashed about its environmental leanings. Lead singer Craig Minowa is an environmental scientist for the Organic Consumers Association and runs the nonprofit label Earthology Records, which is located on an organic farm and powered by geothermal and wind energy. The band records music in a small studio made from reclaimed scrap materials, and their CDs are packed in reused jewel cases (which they hand-clean!) and shrink-wrapped in environmentally benign LDPE plastic rather than the industry-standard toxic PVC. They also donate all profits after expenses to eco-charity efforts.