Leading experts have warned cities need not just to start planning not just for record-breaking temperatures today, but for the heatwaves of tomorrow as well.
In an interview, the global chief heat officer at UN-Habitat and the Atlantic Council’s Adrienne Arsht–Rockefeller Foundation Resilience Center (Arsht-Rock), Eleni Myrivili said cities are heating twice as fast as the average for the rest of the world and have become the “ground zero for global warming”.
Myrivili added urban planners need to start designing cities not just for the record-breaking temperatures currently being seen around the globe, but also for the heatwaves to come, which could be even hotter.
“It is very indicative that Paris, which is a serious city, is actually now planning for scenarios involve 50 degrees Celsius (122 degrees Fahrenheit),” she told me.
“Five years ago, such plans would be unthought of, but now we have to start designing for a much hotter future because it’s not even a question of whether it is going to happen anymore.”
Her comments come as the Copernicus Climate Service publishes new data, which shows June was the 12th consecutive month of global temperatures being 1.5 degrees Celsius (34.5 degrees Fahrenheit) above pre-industrial levels.
According to the analysis, the average temperature for June 2024 in Europe was 1.57°C (34.8 degrees Fahrenheit) above the 1991–2020 average, making it the joint-second warmest June on record for the region.
Dima Zogheib, global nature positive lead at the engineering and sustainable consultancy Arup, said in an interview that the firm has been researching the issue of urban heat in cities across the world, using artificial intelligence and digital heat modelling tools.
Zogheib added the research shows the hottest parts of London experience temperatures at eight degrees higher than nearby greener neighbourhoods.
These tools are also used by Arup to measure the impact of design interventions at a district or city scale.
In the United Arab Emirates, Arup researchers measured the reduction in temperature in a district of the city following the introduction of shading canopies, trees, permeable surfaces and other measure, and have found that the difference there can be as much as 10 degrees Celsius (50 degrees Fahrenheit).
“This research really shows that shading, greening, open space and trees contribute significantly to lowering temperatures in cities,” she told me.
Myrivili added cities have traditionally been designed around their geographical location and very specific local climate conditions.
She added a lot of building materials used today, like concrete, steel, and asphalt absorb heat during the day and slowly release it overnight, which is why temperatures remain high in the evening.
And she said it is those evening temperatures that are the most dangerous and lead to high levels of mortality and morbidity.
Myrivilli also singled out a “lack of nature” in many cities, which helps raise urban heat temperatures.
She referred to a Lancet study from 2023, which claims increasing tree coverage to 30% in European cities could reduce one third of deaths linked to urban heat.
“Creating more green spaces and more water permeable surfaces in cities bring multiple benefits to help you to deal heat,” she added.
“Heat is killing people and if you start creating greener cities, then you have more beautiful cities, more liveable cities, and more equitable cities, because green public spaces are spaces where everyone can take some time off and relax.”
Zogheib mentioned Arup’s work in Dar Es Salaam, using digital technologies to model the growth of the city by 2050 and incorporating nature-based solutions in future plans to address urban heat and flooding.
The project has demonstrated that air temperatures can be reduced by up to five degrees Celsius (41 degrees Fahrenheit) and up to 300 Olympic size swimming pools of rainfall can be stored in the soil
“You can address challenges like floods, urban heat, and green space,” she explained. “It’s a tremendous opportunity to think about every single component of a city and how they all contribute to making places liveable and resilient.”
