Cities across the “US Sun Belt,” like Phoenix and San Antonio, are among the fastest growing in the country. But climate change is making them unlivable. For example, San Antonio has already had more than a dozen days with triple-digit temperatures, and Phoenix has seen a record number of heat-related deaths. The western part of the region is also in the midst of its worst megadrought in the past 1,200 years. Water stores are depleted, wildfires are more common, and cities lack the proper infrastructure to cope with climate change. Vast, spread-out suburbs are filled with concrete that traps the heat, and a reliance on cars that worsens air quality and pollution levels.

“We are seeing places run out of water, no proper subdivision controls to ensure there are enough trees to help lower the heat, and lots of low-density suburbs full of cars that create air pollution that only gets worse in hot weather,” Jesse Keenan, an expert in climate adaption at Tulane University, told the Guardian, “We’ve reached a crunch point.”

Why This Matters

Despite experiencing years of devastating extreme weather, Americans have been moving en masse to regions that are most affected by climate change. A combination of laissez-faire land-use laws and flood insurance subsidies have encouraged development in vulnerable areas, leaving millions at risk of wildfires, heat, and more.

It isn’t just the US. Heatwaves are hitting around the world, and many populous cities are unprepared. In the UK, for instance, hot weather has buckled railways, melted runways, and burst water pipes, necessitating expensive and time-consuming repairs. Meanwhile, cities in India and Pakistan have to adapt to withering wet-bulb temperatures, which can make the heat even more deadly.

There’s currently a 50% chance the world warms at least 1.5 degrees celsius, so cities must prepare for the new normal of increasingly extreme weather.

Some Cities Take Action

Some urban centers are beginning to take action to protect their residents from extreme weather. Last July, Miami appointed Jane Gilbert as its Chief Heat Officer to protect citizens and respond to the climate change effect of deadly extreme heat. Other cities have followed suit:  Phoenix and Los Angeles also appointed CHOs.

Other cities have become “climate havens,” transforming in the face of global warming with adaptive and mitigative actions. In contrast to urban sprawl that contributes to climate change, cities like Duluth and Cincinnati have implemented good infrastructure, affordable housing, public transportation, and walkability -- all important parts of sustainable cities.