Daily Climate: Two decades ago, the strip of sand between the Pacific Ocean and the Andean foothills was empty except for the occasional fig or carob tree. But the northern end of perhaps the world’s driest desert – a harsh and unforgiving clime — is now the center of Peru’s export agriculture industry. Rising demand for irrigation and drinking water is draining the aquifer faster than it can recharge, and a scheme to channel more water from the Andean highlands, which receive seasonal rainfall, is …