It isn't just carbon energy they hate. It's energy. Period!
With the Obama Administration doing it's best to block all carbon energy development and boost so-called green energy alternatives you would think that environmentalists would be cheering. Not so. Now they are trying to block development of solar power projects. This is on top of opposition to nuclear power and wind farms.
Tough question: name one form of energy that environmentalists actually approve of?
Good luck with that.
UPDATE: Good article in Forbes detailing the lengths the environmental movement goes to stalling even renewable energy projects.