The Threat to the Planet

By Jim Hansen

The Weather Makers: How Man Is Changing the Climate and What It Means for Life on Earth

by Tim Flannery

Atlantic Monthly Press, 357 pp., $24.00

Field Notes from a Catastrophe: Man, Nature, and Climate Change

by Elizabeth Kolbert

Bloomsbury, 210 pp., $22.95

An Inconvenient Truth: The Planetary Emergency of Global Warming and What We Can Do About It

by Al Gore

Melcher Media/Rodale, 325 pp., $21.95 (paper)

An Inconvenient Truth

a film directed by Davis Guggenheim

Jim Hansen is Director of the NASA Goddard Institute for Space Studies and Adjunct Professor of Earth and Environmental Sciences at Columbia University's Earth Institute. His opinions are expressed here, he writes, "as personal views under the protection of the First Amendment of the United States Constitution."

1.

Animals are on the run. Plants are migrating too. The Earth's creatures, save for one species, do not have thermostats in their living rooms that they can adjust for an optimum environment. Animals and plants are adapted to specific climate zones, and they can survive only when they are in those zones. Indeed, scientists often define climate zones by the vegetation and animal life that they support. Gardeners and bird watchers are well aware of this, and their handbooks contain maps of the zones in which a tree or flower can survive and the range of each bird species.