Hey, thanks. Sincerely, The Earth.

"And of course, it goes without saying that white people who ride bikes like to talk about how they are saving the earth. If you know a person who rides to work, you should take them aside and say “Hey, thanks. Sincerely, The Earth.” Then give a thumbs up. That white person will ride home on a cloud."

From the hilarious blog, Stuff White People Like.