Unlocking the Climate Puzzle 解开气候之谜 (1)Life has prospered on this planet for nearly four billion years. In that time, climate had fluctuated drastically, from ice ages lasting tens of thousands of years to epochs of steamy heat. With each change, sundry species have benefited and flourished. Others adapted, faltered, or died. Now, many experts believe, humans are imperiling their own ecological niche with the threat of global warming. The vaporous by-products of civilization, in the form of greenhouse gases such as carbon dioxide (C0₂), have trapped enough heat in the atmosphere to raise Earth's average surface air temperature a half degree Celsius (one degree Fahrenheit) during this century. If the trend continues, it could alter climate patterns worldwide-thawing glaciers, boosting sea level, scorching plains into deserts, and shifting vegetation zones. （1）生命在这个星球上已经发展了近四十亿年。在这段时间里，气候有大幅波动，从冰河时代到蒸汽时代延续了几千年。每一次改变，各种物种受益和繁荣。其他适应，步履蹒跚，或死亡。现在，许多专家认为，人类正在通过全球变暖危及自己的生态位。在本世纪，文明的气态副产物，以二氧化碳（ C0₂）等温室气体的形式，把足够的热量困在大气中，来提高地球表面平均气温半摄氏度（1华氏度）。如果这种趋势继续下去，它可能会改变世界范围内的气候模式—融化冰川，提高海平面，把平原烤成沙漠，以及改变植被区。 (2) Or it might not. Global climate depends on combinations of factors interacting in subtle and complex ways that we do not yet fully understand. It is possible that the warming observed during this century may have resulted from natural variations, even though the increase has been much more rapid than what the planet has witnessed over the past hundred centuries. Moreover, the supercomputer simulations used to project future conditions may not...
