KT Tunstall onboard via Nathan Gallagher

Lori Majewski writes on Day 5 of her arctic voyage:

This past summer, the greenest rock stars boasted of their biodiesel tour buses. If only all of them had done their homework on the energy source like KT Tunstall did.

"Biodiesel can be potentially worse than regular diesel," KT declared during a Cape Farewell 2008 info-sharing session this week aboard the Russian sea vessel carrying her, other musicians such as Feist and Vanessa Carlton, and climate change oceanographers. The nine-day High Arctic tour--Cape Farewell's seventh such ocean trek in five years--was organized in the hope that the rockers and other artists will be inspired by the scientists and icy environs to write songs and create other projects to get the public to pay attention to the global warming crisis.

A few days later -- after KT wowed Cape Farewell-ers and Greenlanders alike during an impromptu rendition of "Black Horse and the Cherry Tree" at an Ilulissat bar-- CGG sat down in the ship's lounge with the Scottish newlywed to get the scoop on why biodiesel isn't necessarily the answer for touring musicians.

"The fundamental idea of biodiesel is a good one," KT began. "But the consequences of producing it irresponsibly can be ten times worse than mining fossil fuels. This is due to the destruction of rainforest and essential food crops to grown ethanol instead."

The ideal solution is to grow ethanol crops in areas where food wouldn't survive. But the problem, says KT, arises in that there's currently no way of knowing if the ethanol was grown responsibly. "You can go into a Whole Foods store and know you're buying organic meats and organic vegetables," she explains, "but with biodiesel, you're not privy to where it comes from. I don't know if the guy who owns the gas station even knows where it comes from." So for now, KT is sticking to regular diesel.

Another way KT earns her green badge: On her recent American tour, she forewent an expensive stage set that would eventually be thrown in the garbage in favor of $300 worth of furniture from a San Diego Salvation Army.

"And it was extremely hard to spend that much money there!" she added.

During KT's final show at New York's Town Hall, she gave away props to fans who won rounds of Bingo.

KT Tunstall playing in Ilulissat, via Nathan Gallagher