This attempt at the greening of rock 'n' roll is a righteous cause to be sure, but is the message getting through to the fans? Johnson certainly hopes so. "We don't get to see the positive things or the negative things it's doing until a few years later. A lot of times you come through town and do a show, and if someone was inspired or motivated it may take them a while to start up that club or start up that new business. It takes a while to see the impact. I've met people who've definitely said that they never heard of biodiesel before and now they run their truck off it."
But even Johnson admits that it's all still about the music.
In "All at Once," a song from his latest album, Johnson sings about global warming: "Around the sun / Some say it's going to be the new hell / Some say it's still too early to tell / Some say it really ain't no myth at all."
Another song, "The Three R's" from the "Curious George" movie soundtrack, asks listeners to reduce, reuse and recycle.
"That's a powerful and very flattering thing for me, for these words I've written, to hear people singing them and to hear that is definitely really nice for me. ... It's kind of like church. We say it's like this gathering of humans coming together to share an idea."
It's an idea Johnson hopes will move out of the amphitheater and into fans' homes so that his children and theirs can enjoy the Hawaiian surf and a myriad of other natural wonders for years to come.