Every time you drive to work, or worse yet, fly on a plane, the vehicle emits carbon dioxide that will stay in the atmosphere, warming the planet for thousands of years. Does it have to?
Global warming has become such an overriding emergency that some climate experts are willing to consider schemes for partly shielding the planet from the sun's rays. But no such scheme is a magic bullet.
The wet 20th century, the wettest of the past millennium, the century when Americans built an incredible civilization in the desert, is over : a report. Feb 2008
