Twig impact on heatwave death risks
PLANTING more trees could decrease deaths from higher summer temperatures in cities by a third, new research suggests.
According to the study, of the 6,700 premature deaths linked to higher temperatures in European cities during 2015, one third of these (2,644) could have been prevented by increasing urban tree cover up to 30 per cent.
The modelling study also found that tree cover reduced urban temperatures by an average of 0.4 degrees during the summer.
The study’s lead author, Tamar Iungman, from the Barcelona Institute for Global Health, 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.
“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.” Researchers suggest that urban environments record higher temperatures than the surrounding countryside, generally referred to as “urban heat islands”.
The temperature difference is caused by human activities such as removal of vegetation, the presence of asphalt and the use of building materials that absorb and trap heat, the study suggests.
Intense
Increased temperatures in cities are predicted to become more intense with climate change, resulting in an increasingly urgent need for cities to adapt to improve health outcomes.
In the study scientists estimated death rates of people over 20 years old in 93 European cities between June and August 2015, accounting for some 57 million people in total.
Researchers estimated the number of deaths attributable to urban heat as well as the number of deaths that could be prevented through increasing the tree cover.
The average daily temperature difference between cities and countryside from June — 2015 was cities 1.5 degrees warmer than the surrounding countryside, the study suggests.
Degree
Across all cities, 75 per cent of the population lived in areas with an average summer city temperature difference greater than one degree, and 20 per cent with an average summer temperature difference greater than two degrees, compared with the surrounding countryside.
Researchers say their findings support the idea that urban trees provide public health benefits.