Eliminating Heat Islands: Urban Planning for a Greener Tomorrow
As climate change progresses and cities get warmer, countries will have to discover innovative ways to deal with extreme heat in urban centers. Rising temperatures are becoming increasingly problematic, causing a prevalence of negative impacts on health and physical activity. In addition, extreme heat leads to diminishing workforce productivity in the economy while infrastructure such as roads and rail lines are negatively impacted from heat-related damage.
Currently, 68 million people around the world experience the consequences of extreme heat. If global warming rises by two degrees Celsius, the number of people affected could increase 15-fold, reaching nearly one billion people. With an increase of four degrees Celsius, these effects would be felt by nearly half the Earth’s population. Without prevention measures to mitigate this issue, urban heat will continue to negatively impact worker productivity, raise cooling costs for buildings, and ultimately pose municipal costs of 11% of cities’ gross domestic product (GDP) by 2100. Mortality rates will spike simultaneously. In the U.S., on average, more people are killed by heat waves than any other natural disaster. Similarly, the UK is anticipating a 257% increase in heat-related deaths by 2050, and 535% by 2080.
The “urban heat island effect” refers to the trapping of heat in dense cities and emerged as a concept in the recent upsurge in global warming. This generally results from the replacement of naturally cooling surfaces, like water and vegetation, by surfaces like concrete and asphalt. Cities obtain temperatures of up to 10 degrees Celsius higher than the surrounding rural areas due to man-made infrastructure that absorbs and re-emits heat. Additional factors that accelerate the creation of heat islands can be anything from vehicles sitting in traffic, air conditioners pumping out waste heat, or dark asphalt absorbing and projecting the sun’s rays. Rapid urbanization can thus be seen as turning modern cities into “heat sinks.”
Although dire, the situation is not helpless. It is possible to consider options to mitigate the progressive creation of heat islands. Initiatives in urban planning, which may seem futile, can have transformative results in making cities cooler and more energy efficient. This would create benefits not only for the environment, as pollutants are absorbed from the air, but also for entire populations. Cooling efforts can contribute to the production of oxygen, create a calming, natural setting within hyper-dense cities, reduce health risks, and decrease energy costs for building owners and tenants as they would require less cooling mechanisms. In addition, installation programs for heat-reducing initiatives can contribute to business opportunities and job creation.
Singapore provides a noteworthy example of initiatives that target heat resilience. Starting with the enactment of the “Garden City” plan in 1967, tree-planting and the development of new parks stimulated the beginning of a green transformation within the country. As Singapore modernized, the population grew, and taller buildings occupied the skyline, the plan evolved to incorporate a more intensive approach. By 2009, the Landscaping for Urban Spaces and High-Rises (LUSH) program was launched, requiring new buildings and development projects to inject an amount of greenery proportionate to the size of the site. Such policies can help decrease temperatures up to three degrees Celsius.
The initiative in Singapore, along with similar initiatives across the globe, such as the New York Cool Roofs initiative, encourages the adoption of mechanisms that would reduce the amount of heat absorbed into a city. For instance, a white roof has the potential to be 23 degrees Celsius cooler than a black roof. For someone living on the top floor of an apartment building, the amount of heat absorbed would be a fraction of what it is otherwise.
In becoming more innovative, cities have the opportunity to creatively address the growing global warming problem and evolve into utopias that prioritize and preserve clean energy. Not only will improving our heat resilience be pivotal in mitigating the climate crisis and its associated health risks, but reshaping the way we design our cities can contribute to the overall wellbeing of the entire population.