South Asia has warmed far more slowly than the rest of the world over the past four decades with temperatures rising just 0.09C per decade compared to 0.30C elsewhere on land, according to new climate research. Scientists believe this "warming hole" results from two factors that have masked the true impact of global warming: heavy aerosol pollution that reflects sunlight back to space and expanded irrigation that cools air through evaporation. The protective effect is temporary and comes at a deadly cost. Air pollution currently kills between 2 million and 3 million people annually in South Asia, while extreme heat causes 100,000 to 600,000 deaths. As governments reduce pollution and groundwater depletion limits irrigation expansion, atmospheric scientists predict India will warm at twice the rate of the past 20 years. By 2047, the average Indian could experience a four-fold increase in dangerous heat stress days, threatening a region where only 10% of households have air conditioning.Read more of this story at Slashdot.