Scientists have long recognized that the emergence of a large
mountain range can produce climate change. New work indicates
that the converse is also true. In a report published today in
the journal Nature, researchers propose that chilly waters and
dry weather helped push the Andes skyward. Standing some four
kilometers high, South America's Andes are some of the grandest
peaks in the world. Like other, smaller ranges, they reside on
the boundary of two tectonic plates, the subduction of which
thrust the earth upward. But how the Andes attained their great
size requires additional explanation. This, according to Simon
Lamb of Oxford University and Paul Davies of the University of
California at Los Angeles, is where climate comes in. The
authors suggest that the cooling of water in the so-called Peru-
Chile current system (presumably a consequence of a global
cooling phase that began perhaps 40 million years ago, during
the Eocene epoch) triggered the drying of the west coast of
South America. The resulting re