The world's premier climatologist, Lonnie Thompson has been risking his career and life on the highest and most remote ice caps along the equator, in search of clues to the history of climate change. His most innovative work has taken place on these mountain glaciers, where he collects ice cores that provide detailed information about climate history, reaching back 750,000 years. To gather significant data Thompson has spent more time in the death zone-the environment above eighteen thousand feet-than any man who has ever lived. Scientist and expert climber Mark Bowen joined Thompson's crew on several expeditions; his exciting and brilliantly detailed narrative takes the reader deep inside retreating glaciers from China, across South America, and to Africa to unravel the mysteries of climate. Most important, we learn what Thompson's hard-won data reveals about global warming, the past, and the earth's probable future.