The West Coast drinks from the wind. When westerly gales carry humid air from the Pacific Ocean into the Sierra Nevada and the Cascade mountain ranges, the West turns green, orchards blossom, and reservoirs swell. When those westerlies deflect to the north, hills turn brown, cities ban sprinklers, and forest fires flare. There are consistent bands of westerly winds at about 40 degrees latitude in both hemispheres — near San Francisco in the northern hemisphere, and near Concepción, Chile, in the south. Over the past few decades scientists have seen these westerlies creeping toward the poles. If this shift is a result of climate change and continues, it could have profound implications: Over the next century, Seattle might become as dry as Los Angeles, and California could settle into an era of unending drought. So are the westerlies going to keep drifting away from the equator? Well, if you […]