Well said, Zenyata.
Just because they have an opposing view to the mainstream makes them radical? Do you expect them to lay down to growth etc.? Growth isn't necessarily good and more than often times its not, especially today.
If you want to read about a real radical environmental group, search for Earth First!
For one, I consider them too conservative in their actions and phrases. The Sierra Club has grown to be more of a corporation, while still fighting for environmental issues they make way to many compromises. They definitely have strayed from John Muir's original founding principles. Yes, you could call me a very strong/radical environmentalist.