Wangari Maathai is in "The 11th Hour"

"Well, I don’t only think that the biosphere is in trouble, I know it is. I just have to look around in the environment, in which I live.

In my own part of the part of the world, I keep telling people, let us not cut trees irresponsibly. Let us not destroy especially the forested mountains. Because if you destroy the forests on these mountains, the rivers will stop flowing and the rains will become irregular and the crops will fail and you will die of hunger and starvation. Now the problem is, people don’t make those linkages."

Treehugger