Planting more trees could mean fewer people die from increasingly hot summer temperatures in cities, a study has found.
Increasing the level of tree cover from the European average from 14.9% to 30% can lower the temperature in cities by 0.4°C, which could reduce heat-related deaths by 39.5% , based on unique modeling of 93 European countries. cities by an international team of researchers.
Lead author Tamara Iungman, from the Barcelona Institute of Global Health, said: “This is becoming increasingly urgent as Europe experiences more extreme temperature fluctuations caused by climate change.
“We already know that high temperatures in urban environments are associated with negative health outcomes, such as cardiorespiratory failure, hospitalization and premature death.”
Her team wants to influence policy makers to make cities greener, “more sustainable, resilient and healthy” as well as to mitigate climate degradation, she added, as heat-related illnesses and deaths are expected to account for an even greater burden on health services in the coming years. decade than cold temperatures.
The researchers used the mortality data to estimate the potential reduction in deaths from lower temperatures due to increased tree cover. Using data from 2015, they estimated that of the 6,700 premature deaths that year attributed to higher urban temperatures, 2,644 could have been avoided if forest cover had increased.
The cities most likely to benefit from increased tree cover are in Southern and Eastern Europe, where summer temperatures are highest and tree cover tends to be lower.
In Cluj-Napoca in Romania – which recorded the highest number of premature heat-related deaths in 2015, at 32 per 100,000 people – tree cover is just 7%. In Lisbon, Portugal it is as low as 3.6% and in Barcelona it is 8.4%. This compares to 15.5% in London and 34% in Oslo.
Study co-author Mark Nieuwenhuijsen, a researcher at the Barcelona Institute for Global Health, said the team chose 30% because it’s a goal that many cities are currently working towards.
He said there was no need for buildings to be razed and replaced with parks, as there is enough space to plant more trees in all the towns the team looked at. He welcomed initiatives such as the EU’s 3 billion tree plan and the UK government’s proposal to ensure that every home is within 15 minutes’ walk of a green space, while noting that policy makers must ensure that trees are evenly distributed between rich and poor neighborhoods.
He added that cities “too dominated by cars” should consider replacing paved roads, which absorb heat, with trees.
Planting more trees in cities should be a priority because it brings a wide range of health benefits beyond reducing heat-related deaths, he added, including reducing cardiovascular disease. , dementia and poor mental health.
Professor Yadvinder Malhi, professor of ecosystem science at Oxford University, who was not involved in the study, said: “More than half of the world’s population lives in towns and cities, so trees are going to be key to making urban areas resilient.” to climate change and improve urban environments. Urban trees provide many co-benefits beyond adaptation to climate change: numerous studies show that simply seeing and smelling trees is beneficial for health and well-being, as well as improvement of urban biodiversity. But most tree cover is found in cities and affluent neighborhoods, so improving urban tree cover can reduce this inequality and in particular reduce the high vulnerability of poorer neighborhoods to climate change.