Malaria is a global scourge: despite centuries of efforts to combat the mosquito-borne disease, it still kills between 660,000 to 1.2 million people a year, according to World Health Organization data from 2010. Astoundingly, experts estimate that around 300 million people are infected with the disease every year or about 4 percent of the world’s total population. And these stats may only get worse. For years scientists have vigorously debated whether or not malaria will expand as global warming worsens, but a new study in Science lays down the first hard evidence.