The Rational Optimist: Intensive Farming
Although people generally are optimistic about their own lives, they are pessimistic about the future of the planet. But there's good reason to believe that the more progress we make, and the richer we get, the better off the planet will be.
During the 20th century, intensive farming has saved 44% of planet earth for wilderness. Intensification, mechanization, and use of agricultural inputs during the 20th century has been hugely beneficial for the planet. New technologies in the 21st century should yield similar gains - enabling us to turn more land back to Mother Nature but still feed 9+ billion people on the planet.