As the days shorten in the northern hemisphere and memories of this summer’s sweltering temperatures begin to fade, city planners and public health professionals alike remain on high alert for what comes next. Intense heatwaves, droughts and forest fires look set to become regular occurrences as part of the unfolding climate emergency. The impact of dangerously high temperatures on urban dwellers can be catastrophic and the mortality rates of older age groups are particularly affected.
There is only so much that conventional healthcare campaigns can do to protect older people in these conditions, so the question being asked by city policymakers is whether design interventions can be introduced to the built environment that reduce what is known as the urban heat island effect.
Recent research sets out the scale of the problem. According to a study led by the Barcelona Institute for Global Health with the French National Institute of Health, the summer of 2022 – the hottest ever recorded in Europe – saw 61,672 heat-attributable deaths between the 30th of May and the 4th of September. The analysis, published in Nature Medicine, showed a very marked increase in mortality in the older age groups, and especially in women. The research team estimated that there were 4,822 deaths among those under 65; 9,226 deaths among those between 65 and 79; and 36,848 deaths among those over 79.
Several factors influence why older people are more vulnerable to heat and at greater risk of death during summer. They are less mobile, and their bodies less efficient at regulating temperature and adapting to heat stress; they tend to have pre-existing health conditions which can be exacerbated by heat; and their use of certain medications can interfere with the body’s ability to cool down.
Looking ahead, things are set to get worse. In a paper published in Nature Communications, an international research team from Boston and Venice examined global projections for the heat exposure of older people and issued a stark warning predicting that up to 250 million more elderly people worldwide are expected to face dangerous heat exposure by 2050, compared with the numbers affected today. The effects are projected to be the most severe in Asia and Africa, which may also have the lowest adaptive capacities, according to the researchers.
Lack of cooling green space across the Global South deepens the problem, with the urban heat island effect making many cities hotter than rural areas. Researchers from Nanjing, Exeter, Aarhus and North Carolina State universities used satellite data on the world’s 500 largest cities to assess ‘cooling capacity’ – the extent to which urban green spaces cool down a city’s surface temperatures – and their findings underline the need to cool down cities with green interventions.
But while the academic evidence is at hand, design practice on the ground is still struggling to gain momentum as hot cities sprawl and expand. The challenges at city level can include a lack of funding, a lack of political will and a lack of technical know-how. Of course there are notable exceptions. Melbourne’s ‘Green Our City’ strategic action plan is leading a clutch of Australian cities in speeding up the introduction of green roofs, walls and façades to combat the effects of climate change.
There are also standout projects which show the art of the possible. One of my favourite schemes is Korean: in the early 2000s, the Seoul Metropolitan Government set out to revitalise the Cheonggyecheon area of the city and create a more sustainable, pedestrian-friendly public area. This audacious project revolved around a political decision by the mayor to dismantle a polluting four-lane elevated highway that covered the Cheonggyecheon stream and carried 170,000 vehicles daily.
By opening up the urban waterway and introducing a vibrant space mix, the project reduced the urban heat island effect by 4.5 per cent and air pollution by more than 10 per cent. Pedestrian activity rose by 76 per cent and bus ridership by 15 per cent, according to an impact survey. Private investors poured into what was a low-grade industrial area with large numbers of older residents to build new retail, office and hospitality schemes, leading to a rise in land prices which covered most of the costs. The entire project was delivered in just four years to coincide with the mayor’s term of office.
Seoul’s Cheonggyecheon scheme shows what can be achieved when the political drive, funding and engineering nous are all in place. As ageing urban populations in Europe face up to soaring temperatures, we’re going to need that kind of energy and vision closer to home.
Cheonggyecheon before
About the Author
Jeremy Myerson is Professor Emeritus in the Helen Hamlyn Centre for Design, Royal College of Art, an Honorary Professorial Fellow at the Oxford Institute of Population Ageing, and Co-founder and Chair of the annual Healthy City Design Congress, which takes this year in Liverpool on 15-16 October 2024.
Opinions of the blogger is their own and not endorsed by the Institute
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