دانلود کتاب Water from Heaven

Covering a vast array of scientific fields and recent discoveries, this book tracks a remarkable substance in its liquid, solid, and gaseous states as it cycles through the seas, the atmosphere, land, icecaps and under the earth. Robert Kandel describes what we humans are doing to the water cycle and the climate and explains where we are heading. The book investigates how nuclear reactions in the interiors of stars produce the oxygen needed to form H20. After showing how the atmosphereВґs motions apportion moisture, the book follows the course of water over the land, into the soil, and through plants back to the atmosphere. From there, water travels along streams and great rivers back to the seas. The role of irrigation, the quest for clean water for cities, and the problems of pollution and public health are important elements of the story. The author considers climate change and how political and economic decisions that we make today will affect water resources for the next century. Finally, the author considers the geopolitical role of water and the tensions generated by the control of a nationВґs water by other countries who ''own'' the watershed or upstream resources.