A couple of quick additions to Meredith's great story about the violent language of environmentalists:

"Every time someone dies as a result of floods in Bangladesh, an airline executive should be dragged out of his office and drowned."  --Environmental author George Monibot

"If I were reincarnated, I would wish to be returned to Earth as a killer virus to lower human population levels." -- Prince Phillip, World Wildlife Fund

"Phasing out the human race will solve every problem on earth, social and environmental." --Dave Forman, Earth First!

All of these (and more) are available in An Inconvenient Book, by some guy named Glenn Beck.