There is no place more remote than the Arctic and Antarctic, but their remoteness has not kept them isolated: Pollutants released in developed lands travel on air and water currents into the polar regions, the ozone hole has widened over Antarctica, and global warming is causing its greatest damage in the world's iciest locales. Along with an understanding of how human activities are changing the polar regions has come an appreciation of their importance in global climate, biological productivity, and biodiversity. ''Polar Regions'' is a crucial new book that explains how many scientists are providing forewarning of the changes that will come to the entire planet if society continues on its current trajectory. Featuring full-color photographs and illustrations, sidebars, suggestions for further reading, and Web sites, this book arms readers with the information necessary to take a stand in protecting our fragile planet.