The future of cities has never been brighter. More people want to live in them (two-thirds of the planet will be urban by 2050, according to the UN), and there is a general trend towards more sustainable and inventive development.
On the other hand, cities have never been more at risk. Climate change is making natural disasters from storms, storm surges, and river flooding more likely, and the need to accommodate millions more people is pushing cities to build in dangerous areas, like on flood plains. Cities represent both great hope for the future, but also contain enormous peril.
Swiss Re, one of the world's biggest insurance companies, just came out with a new report about the climate risks cities face. It doesn't make for comfortable reading. Many of the places we think of as success stories today—places like Shenzhen and Guangzhou, in China, or Jakarta, in Indonesia—are in grave danger of natural catastrophe, the report says. More established cities, like Tokyo and Nagoya, in Japan (tsunamis, earthquakes, and storms), as well as Los Angeles or San Francisco (earthquakes) are also at risk.
The report points out that Hurricane Sandy was hugely disruptive to the New York area last Fall. But, comparatively speaking, it wasn't particularly severe in its wind speed or its effect, at least as measured in the number of people killed, injured, or evacuated). Disasters in other places could make the Sandy aftermath look like a trifling inconvenience.
Swiss Re looks at how 616 cities could be affected by five disaster types: earthquake, storm, storm surge, tsunami, and river flood. It estimates the number of people who might die, suffer injury, or have to be evacuated. And it focuses on exceptional events: storms worse than Sandy, or as grave as the 2011 Tohoku earthquake in Japan—the most expensive disaster in history. These are the type of events for which conventional protection measures fail, the report says.
The report makes the case for more "resilience" measures, better planning, and construction (poor practices, it says, adds to clean-up costs). "Sandy showed us how vulnerable our cities are, and how fast a breakdown of critical infrastructure can happen, particularly in areas with a high concentration of people and properties," the report's authors write. "This is why the need for disaster management is nowhere more urgent than in the world’s sprawling urban centers."
Flooding is the biggest threat, as most cities are built along waterways:
Across the 616 cities assessed, river flooding poses a threat to over 379 million residents. Over 283 million inhabitants could potentially be affected by earthquakes, and 157 million people are at risk from strong winds. In many cases, urban populations must be prepared to cope with more than one hazard.
The Pearl River Delta (Hong Kong, Shenzhen, Dongguan, Macau, and Guangzhou) is home to the greatest number of residents at risk from natural disaster (storm, storm surge, and river flood). Tokyo, Taipei, and Manila are at risk of both big storm surges and earthquakes.
Tokyo-Yokohama is the biggest city at risk of an earthquake, followed by cities like Los Angeles, Tehran, and Tashkent (Uzbekistan's capital). East Asia has eight of the 10 cities most at risk from storm surges. Mumbai and Chennai, in India, make up the other two. The first non-Asian cities are London (in 18th place) and Miami (23rd).
In North America, Los Angeles, Mexico City, and San Francisco have the greatest number of people potentially affected by one of five perils. Los Angeles (0.93), New York-Newark (0.62), and San Francisco (0.47) run the greatest risk economically.