Exposure to heat has been associated with premature mortality, cardiorespiratory disease and hospital admissions. This is particularly true for heat waves, but also occurs with moderately high temperatures in summer. Cities are especially vulnerable to higher temperatures. Less vegetation, higher population density, and impermeable surfaces for buildings and roads, including asphalt, lead to a temperature difference between the city and surrounding areas — a phenomenon called urban heat island. Given the ongoing global warming and urban growth, this effect is expected to worsen over the next decades.
Over four percent of deaths in cities during the summer months are due to urban heat islands, and one third of these deaths could be prevented by reaching a tree cover of 30%, according to a modelling study published in The Lancet and led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by “la Caixa” Foundation. The study results, obtained with data from 93 European cities, highlight the substantial benefits of planting more trees in cities to attenuate the impact of climate change.
— source Barcelona Institute for Global Health (ISGlobal) | Jan 31, 2023