I think that the abolitionist movement and the environmental movement have a lot in common. I will not be so over the top as to say that trees and human life are on the same level, but both movements have lofty goals and have fought against long, overwhelming opposition.
In spite of all the gains we have made to live in a more sustainable and environmentally ethical way, we are still on the down hill. We may have slowed the decline but we are still raping the earth. The environmental movement has not yet had its Civil War.