This is how cities around the world are adapting to soaring temperatures

As cities worldwide battle rising temperatures, they are painting their roads white and planting trees to help keep residents cool.

A s climate change causes Greenland’s ice sheet to melt and intensifies heat waves, scientists warn that the Earth could transform into a “hothouse”.

Cities around the world are already feeling the impacts and are struggling to cope with intense heat. 

European cities baked this summer as heat waves swept the continent, breaking temperature records in over a dozen countries and causing mass transport disruption. 
Climate change will lead to more intense heat waves, water scarcity and air pollution, scientists say. 

By 2050, the urban population affected by heat will increase by 800% and more than 970 cities will experience average summertime temperature highs of  35 ̊C, according to C40 Cities – a coalition of almost 100 cities committed to addressing climate change. Today just 354 cities are that hot. 

Heat particularly affects the poorest and most vulnerable people in cities, as they live in small apartments without proper ventilation or greenery, according to Simone Sandholz, associate academic officer at the United Nations University’s Institute for Environment and Human Security.

Cities around the world are already taking action to protect their residents from soaring temperatures. From white roofs to cool islands, cities are finding innovative ways to relieve heat stress.

Medellin’s ‘Green Corridors’

Colombia’s second-largest city, Medellin, has embraced nature as a cooling solution.

Instead of cranking up the air conditioning, which leads to a huge surge in power demand and contributes to global warming, Medellin has implemented the ‘Green Corridors’ project, transforming 18 roads and 12 waterways into green havens.

The Green Corridors help reduce the urban heat island effect. Pollution and high population density turn cities into urban heat islands, with significantly higher temperatures than the surrounding rural areas. 

Trees and shrubs have reduced the surface temperature in Medellin by 2-3 ̊C and have also improved air quality and biodiversity, according to Regina Vetter, who leads the Cool Cities Network at C40 Cities.

Los Angeles’ white streets

By mid-century, Los Angeles could face 22 days of extreme heat – 35 ̊C and above – every year, according to a 2015 study

To beat the heat, the city has started painting its roads and pavements with a reflective white coating called CoolSeal. 

Dark asphalt covering city roads bakes when temperatures rise, absorbing between 80-95%  of the sun’s rays. White roads reflects the rays instead of absorbing them and can significantly lower temperatures. 

The CoolSeal coating can keep roads up to 5.55°C cooler – a vital difference as urban temperatures continue to rise.

Paris’ ‘cool islands’

France recorded its hottest day ever last month, with temperatures in Paris reaching a scorching 42.6°C.

After a heat wave in 2003 contributed to tens of thousands of premature deaths, Paris took important heat mitigation measures, including the installation of over 900 ‘cool islands.’

These cool islands include shaded parks, air-conditioned libraries, and outdoor pools where people can escape when it is very hot.

“A mobile application, that uses real-time satellite data to estimate the temperature, humidity and discomfort index across the city, helps to quickly locate the nearest ‘cool island’ for the user and the freshest route to get there,” explained Vetter.

New York’s reflective roofs

Faced with rising heat, New York painted over 9.2 million square feet of rooftops white, to offset greenhouse gas emissions and keep buildings cool. 

The CoolRoofs project is part of New York’s goal to cut carbon emissions by 80% by 2050. 

The white reflective paint significantly reduces temperatures inside the building and helps lower air conditioning costs, according to Small Business Services, the company that runs the project. 

White roofs reduce cooling costs by 10-30% and can lower surface temperatures by up to 3°C, according to a 2014 study.

The ideas presented in this article aim to inspire adaptation action – they are the views of the author and do not necessarily reflect those of the Global Center on Adaptation.

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