Which environmentalist do you feel made the greatest contribution to environmental science today? Why?

In my opinion I think that Franklin Delano Roosevelt made me feel that he has done great accomplishments towards the environment. He has done many things including establishing the WPA, CCC, AND TVA. These programs employed men to plant trees, build roads and paths on the national parks and controlled flooding. He allowed many people to get easy job to hat least have a little bit of money in their pockets.