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Cities Will Bake Under Climate Change, Experts Say; Here’s Why

Flickr / Pedro Szekely

New York, Tokyo, Mumbai, London, Beijing. The big cities of the world all have distinct personalities, but they share a few defining features: buildings, cars, and people.

And if you ever walked down an urban sidewalk in the summertime, you know that it can get very hot.

That’s because all the asphalt and concrete creates something called the “Urban Island Effect:” the dark colors absorb sunlight and heat and amplify the temperature, like an oven getting hot. All the heat generated by cars and air conditioners further adds to the effect.

In our era of global warming, this dynamic makes cities especially vulnerable.

Read More: How a Tiny Alaska Town Is Leading the Way on Climate Change

The world’s cities are expected to warm at least 2.6 degrees Celsius more than the rest of the planet by 2100, according to a new study published in Nature Climate Change.

"The focus has been so long on global climate change that we forgot about the local effects," co-author Richard Tol, economics professor at the University of Sussex, England, told Reuters.

"Ignoring the urban heat island effect leads to a fairly drastic underestimate of the total impact of climate change," he said.

The economic costs of this overheating will be drastic — the worst-hit cities stand lose up to 10.9% of gross domestic product as workers become less productive and the climate becomes unlivable.

By 2050, up to 70% of the global population could be living in cities, which currently make up just 1% of the Earth’s surface.

Read More: Why Cities May Be the Key to Stopping Climate Change

It’s not just overheating that will damage cities in the future. Many of the world’s most bustling cities are also coastal, which leaves them vulnerable to rising sea levels and extreme storms, according to various studies.

In fact, cities like Miami, Mumbai, Chengdu, and New Orleans could be underwater by the end of the century, making its inhabitants some of the hundreds of millions of people who are expected to be displaced by climate change in that time frame.

But all this gloomy forecasting is also spurring cities to tackle climate change head-on.

As federal governments dither, cities are adopting ambitious climate policies that curb emissions and create more resilient environments.

Read More: India’s Ambitious Mission: A New, Sustainable, 'Smart' City by 2019

For instance, New York aims to lower its emissions from 2005 levels by 80% in 2050. The city is also embarking on a project to paint asphalt rooftops white so that they reflect rather than trap heat and line streets with as many trees as possible.

It’s this kind of inventiveness — turning liabilities into assets — that could turn cities into oases rather than deserts.