Global Warming Cycles focuses on the mechanisms that caused past climate changes, putting the Earth repeatedly into and out of ice ages. It compares natural cycles with today's rapid global warming, caused principally by the behavior of humans. This timely new volume presents the many physical factors that shape the Earth's climate, examining the ones that are out of our control as well as the ones that humans have a direct impact on. It also looks at how scientists use landform clues from the past to assess global warming and how they apply that knowledge to the future to help prepare current and future society for what is to come.