The deadly global heatwave has made it impossible to ignore: in cities worldwide, we are now divided into the cool haves and the hot have-nots
The World Health Organisation says that 60% of people will live in cities by 2030, and the more densely populated they become, the hotter they’ll get. Considering that recent predictions warn temperatures in South Asia will exceed the limits of human survival by the end of the century, every degree counts. Even this year, 65 people have perished from nearly 44C (111F) heat in Karachi, Pakistan – a city used to extreme heat.
But the impact is not evenly distributed. For example, there is a strong correlation between an area’s green spaces and its wealth; when shade from tree canopies can lower surfaces’ peak temperature by 11–25°C, “landscape is a predictor for morbidity in heatwaves”, says Tarik Benmarhnia, public health researcher at University of California San Diego. A review paper he recently co-authored found that people living in less vegetated areas had a 5% higher risk of death from heat-related causes.
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Across the board, lack of equality has been found to feed the urban furnaces. The US researchers who in 2013 uncovered the racial divide in urban heat vulnerability discovered that the more segregated a city was, the hotter it was for everyone. Rachel Morello-Frosch, one of the co-authors, told the LA Times at the time that “this pattern of racial segregation appears to increase everyone’s risk of living in a heat-prone environment”.
Treating cities as a whole, ghettos and all, is a more effective way to tackle extreme urban heat, they found. Researchers recommended planting more trees and increasing light-coloured surfaces to reduce the overall heat island effect, adding that urban planning to mitigate future extreme heat “should proactively incorporate an environmental justice perspective and address racial/ethnic disparities”.
Working to break social isolation, says Benmarhnia, “is a win-win situation”, with the added benefit of bringing the “invisible” people most at risk – like the homeless, and illegal immigrants – back into the community, where they can be looked after.
Montreal first implemented a similar heat action plan in 2004, reducing mortality on hot days by 2.52 deaths per day, but as the heat waves intensify, it is likely that this will need to be reassessed. Nadler says the devastating impacts of global warming are only just beginning to dawn on everyone. “Cities will have to rethink how we prepare for these emergencies and what we’re able to offer to all of our citizens – from the most affluent, to the most vulnerable.”
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