Dr. S. Dillon Ripley, secretary of the Smithsonian Institute, believes that in 25 years, somewhere between 75 and 80 percent of all the species of living animals will be extinct.

Teddy Roosevelt of course was a great outdoorsman all his life.

In the state of Wisconsin it's mandated that teachers in the social sciences and hard sciences have to start giving environmental education by the first grade, through high school

Loads of chemicals and hazardous wastes have been introduced into the atmosphere that didn't even exist in 1948. The environmental condition of the planet is far worse than it was 42 years ago.

The issues are by some geometric number - 100 or 200 or 500 - times more complicated today than we appreciated them to be when Franklin Roosevelt was around.

I think the internal combustion engine will disappear from the streets of our cities in the next thirty years because transportation will be mass transportation, or probably electrical power.

We must realize that we're all part of a web of life around the world. Anytime you extinguish a species, the consequences are serious.