Planting more trees could decrease deaths from higher summer temperatures in cities by a third, according to a modelling study published in The Lancet journal. The study of 93 European cities found that increasing tree cover up to 30 per cent can help lower the temperature of urban environments by an average of 0.4 degrees Celsius and prevent heat-related deaths. Of the 6,700 premature deaths attributed to higher temperatures in cities during 2015, one third of these (2,644) could have been prevented by increasing urban tree cover up to 30 per cent, the researchers said. These findings highlight the need for more sustainable and climate-resilient strategies to be integrated into local policy decisions to aid climate change adaptation and improve population health, they said. “We already know that high temperatures in urban environments are associated with negative health outcomes, such as cardio-respiratory failure, hospital admission, and premature death,” said study lead author Tamar Lungman from Barcelona Institute for Global Health in Spain “This study is the largest of its kind, and the first to specifically look at premature mortality caused by higher temperatures in cities and the number of deaths that could be prevented by increasing tree cover,” Lungman said. The researchers estimated mortality rates of residents over 20 years old in 93 European cities between June and August 2015, accounting for 57 million inhabitants in total, Science daily reported. Mortality data from this period was analyzed with daily average city temperatures in two modeling scenarios: the first comparing the city temperature without urban heat islands to city temperature with urban heat islands, and the second simulating the temperature reduction as a consequence of increasing the tree cover to 30 percent. Exposure response functions were used to estimate the number of deaths attributable to urban heat as well as the number of deaths that could be prevented through increasing the tree cover. In total, 6,700 premature deaths could be attributed to hotter urban temperatures during the summer months, accounting for 4.3 percent of summer mortality and 1.8 percent of year-round mortality.