Brian Eno, the British musician and ambient-music pioneer, spends a lot of time thinking about how he can impact the world in ways that will make it better. He’s a founding member of the Long Now Foundation, a 15-year-old California nonprofit that promotes slower, smarter thinking, and a trustee of ClientEarth, a London-based environmental law firm. He’s also involved with Music Declares Emergency, a global group of artists and organizations that coordinates activities that direct the music industry toward a carbon-neutral future.