Packed with photos, cool facts, and dozens of activities, this spiral-bound, hardcover book is the first kids guide to the American Museum of Natural History. They'll learn as they go, following clues to a Museum-wide scavenger hunt through towering totem poles and the world's largest collection of dinosaur fossils. Find ancient sharks, your weight on the moon, and a board game that spread around the world. Get the inside scoop on how much the blue whale model weighs or how to keep a 34-ton meteorite from crashing through the floor. Puzzles, games, and great science content engage kids of all ages—and make this a souvenir they'll treasure.
Nuclear weapons were the first technology to threaten us with extinction, but they will not be the last, nor even the most dangerous. A species-destroying exchange of fissile weapons looks less likely now that the Cold War has ended, and arsenals have shrunk. There are still tens of thousands of nukes, enough to incinerate all of Earth’s dense population centres, but not enough to target every human being. The only way nuclear war will wipe out humanity is by triggering nuclear winter, a crop-killing climate shift that occurs when smoldering cities send Sun-blocking soot into the stratosphere. But it’s not clear that nuke-levelled cities would burn long or strong enough to lift soot that high. The Kuwait oil field fires blazed for ten months straight, roaring through 6 million barrels of oil a day, but little smoke reached the stratosphere. A global nuclear war would likely leave some decimated version of humanity in its wake; perhaps one with deeply rooted cultural taboos concerning war and weaponry.
Droughts by themselves cannot cause desertification. Drought is just a contributing factor. The causes are social and economic, having to do with access to resources, power and economics. Droughts are common in arid and semiarid lands, and well-managed lands can recover from drought when the rains return. Continued land abuse during droughts, however, increases land degradation. Increased population and livestock pressure on marginal lands has accelerated desertification. In some areas, nomads moving to less arid areas disrupt the local ecosystem and increase the rate of erosion of the land. Nomads are trying to escape the desert, but because of their land-use practices, they bring the desert with them.