دانلود کتاب Ice Age Extinction: Cause and Human Consequences

Global warming seen from the other side: by the end of the last ice age, the earth had lost most of its large animal species and most of its humans. In a novel approach the author argues that the main cause of this catastrophic extinction was a drastic reduction in atmospheric carbon dioxide, due to the long period of cold, and he backs up his theory with scientific explanations given in clear language for the general reader. The author explores the causes of Earth s cyclical temperature changes and shows how those temperature shifts touch off a chain of events in the atmosphere, in the oceans and on land. Cold temperature was the trigger; and the resultant reduction in carbon dioxide, he argues, was the bullet that killed off so many species. The re-warming released more carbon dioxide into the atmosphere and fueled a resurgence which we are still enjoying. In addition, the author describes the human responses to increases in atmospheric carbon dioxide after the last ice age and in the last 150 years. Near the end of the last ice age, atmospheric carbon dioxide was about half of what it is today. Due to the lack of carbon dioxide, most of the vegetation disappeared from the middle and high latitudes. Without plants to eat, many large animals became extinct; North America lost three-fourths of its large animals including the woolly mammoth, mastodon, and saber tooth cat. Humans, too, had little to eat in these areas and their population declined dramatically. The book then explains how and why atmospheric carbon dioxide increased by about 50% after the last ice age ended, encouraging a population explosion among plants, animals and humans, all of which then migrated into many previously barren areas. More recently, the 28% increase in atmospheric carbon dioxide in the last 150 years has caused a six-fold increase in the human population. Changes in the next 300 years will reverse some of the current trends. There have been some books on the causes of extinction over the last forty years, but all looked at other causes and none examined the role of low atmospheric carbon dioxide. This book has value for anyone interested in the ice age extinction; glaciers; the glacial cycle; the atmosphere and oceans; the past and future of plants, animals, and humans. It provides long-term information on atmospheric carbon dioxide, global warming and cooling.