Large parts of England and Wales are at risk of becoming breeding grounds for malaria as global warming heats up local temperatures, according to a study by Durham University scientists commissioned by the Brits’ Department of Health. Increased temperatures encourage mosquitoes to breed and feed more rapidly, and they speed up the maturation of the malaria parasite. At present, no British mosquitoes are known to carry malaria, but one local species is capable of transmitting the disease. Malaria was once common in much of the U.K., contributing to large numbers of deaths in the 16th through the 19th centuries. Using a mathematical model, the researchers predicted that if global warming continued at its current rate, the disease could become a major threat again within 50 years, and could plague the U.K. for up to four months a year by the end of the century.