Climate change will increase New York's heat wave deaths, pushing up the incidence of temperature-related deaths within decades, researchers say. Scientists at Columbia University in New York have matched daily temperature data for Manhattan with death rates between 1982 and 1999 to estimate how sensitive the city's residents are to temperatures, combing that with future forecasts of temperature rises from climate change to estimate future death rates. Writing in the journal Nature Climate Change, they reported in all their 16 models temperature-related deaths increased almost immediately, NewScientist.com reported Tuesday. Death tolls from heat rose by roughly 6 percent by 2020, 10 to 15 percent by 2050 and up to 30 percent by 2080, the models showed. The biggest increases occurred in May and September and the death toll might double by 2080 during these months, Columbia climate scientist Radley Horton said. "Today New York doesn't think about heat waves in those months, but in the future they may be part of the summer," he said.