Taking progress and problems into account, the scientists give their final word on the state of the planet.

• E. O. Wilson, sociobiologist, Harvard University — The clearing of tropical forests has not slowed in the past ten years and threatens to destroy massive amounts of habitat. If awareness of the problem doesn’t facilitate change, nothing will.

• Jane Lubchenco, marine ecologist, Oregon State University — Only when ecosystem services such as climate regulation, the cleansing of air and water, and the creation of fertile soils are lost will we realize their true value.

• Sherry Rowland, atmospheric chemist, University of California, Irvine — A dramatic climate change may be required to focus people’s attention on the planet’s health.

• Wes Jackson, crop geneticist, The Land Institute — Agriculture and the need to feed growing numbers of people has a direct impact on the oceans. If we don’t so something about agriculture, the wilderness as well as the oceans are doomed.

• Richard Barber, oceanographer, Duke University — The most important thing average citizens can do is to tell our leaders we want answers. Our government has demystified hurricanes by showing how they occur and predicting when they will develop. That has allowed us to respond in enough time to reduce suffering. What we need now is the same kind of demystification of climate change.

• Theo Colborn, zoologist, World Wildlife Fund — Enough evidence exists to prove that petroleum-derived chemicals can enter the womb and hinder the development of the brain, immune system, and reproductive system.

• Hal Mooney, environmental biologist, Stanford University — One person or a small group can awaken the public to the importance of conservation issues, but scientists must make their findings clear and compelling to the general public and policymakers in order for change to occur.