Climate Change: A Runaway Train?

The author discusses scientific evidence regarding the earth's climactic changes. He reports most scientists agree that earth's temperature has risen over the past century and that carbon dioxide is one of the primary greenhouse gases that contribute to global warming. The human species has reshaped Earth's landscapes on an ever-larger and lasting scale. The world's leading scientists tell us that a gradual warming of our climate is under way and will continue. This long-term warming trend poses serious risk to the world's economy and to the environment.