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.