The eminent Harvard naturalist and Pulitzer Prize winner Edward Wilson marshals all the prodigious powers of his intellect and imagination in this impassioned call to ensure the future of life. Opening with an imagined conversation with Henry David Thoreau at Walden Pond, he writes that he has come "to explain to you, and in reality to others and not least to myself, what has happened to the world we both have loved." Based on a love affair with the natural world that spans 70 years, Wilson combines lyrical descriptions with dire warnings and remarkable stories of flora and fauna on the edge of extinction with hard economics. How many species are we really losing? Is environmentalism truly contrary to economic development? And how can we save the planet? Wilson has penned an eloquent plea for the need for a global land ethic and offers the strategies necessary to ensure life on earth based on foresight, moral courage, and the best tools that science and technology can provide.