you have an interesting definition of Fascism, as you define it as any system that accounts for the externalities of corporations. I do not support Greenpeace in particular, as I believe their stance on nuclear power to be wrong, but I find your arguments against environmentalism to ignore the human costs associated with environmental catastrophes.
Environmentalism is not only about caring for animals. The way that I see it, life is rather hard to exterminate and that nature will eventually adapt to whatever way we change the planet. Chemical pollution poisons human water supplies while smog poisons our lungs. It is the poor that have to live with these consequences more than anyone. Is any law that protects us from mercury in our water supplies inherently fascist?