Climate change is going to affect every city on the planet in some way—but not necessarily in the same way. For those cities already adapting to it, strong, decisive action may spell the difference between surviving global warming and succumbing to it. As for those cities that just haven’t gotten around to it yet, they’re likely to discover that investing in climate-change adaptation isn’t like building a new ballpark or convention center. Typhoons and tsunamis don’t care whether your most recent bond measure has passed; droughts and heat waves can’t be expected to wait around for the results of referenda or other ballot initiatives. Any city that treats adaptation as something easily back-burnered is going to get, well, burned. Or flooded. Or, more likely, burned, flooded, and parched—quite possibly all at the same time.
The truth is, a number of very big cities are headed for big trouble. But others have managed to pull themselves together and come up with seriously smart plans for meeting climate change head-on. So whether you consider yourself to be a globe-trotter or just a concerned global citizen, here—for your consideration, your edification, and your retirement planning—are the world’s five worst and five best cities for riding out the tumultuous future that climate change is creating for us.
Five cities that climate change is going to make almost wholly uninhabitable.
PHOENIX You have to wonder what it does to the Phoenician psyche when fancy-pants cultural historians routinely dismiss Phoenix as “The World’s Least Sustainable City” in the subtitles of their books, or when they predict this sprawling anchor of the American Southwest will soon become a desiccated and depopulated archaeological site—“like the Jericho or Ur of the Chaldees, with the shriveled relics of golf courses and the dusty hulls of swimming pools added on,” as one essayist described it. But whatever effect it has, it clearly hasn’t made residents any humbler in the face of their city’s imminent day of reckoning. Sixty years ago, nighttime temperatures in Phoenix almost never crept above 90 degrees Fahrenheit. Now, thanks to the dreaded urban heat island effect, nights in the 90s are commonplace. In 2009, Jonathan Overpeck, a climate scientist at the University of Arizona, told an Arizona legislative panel that temperatures in Phoenix could regularly exceed 130 degrees by the second half of the century. That’ll be just in time for the metro area’s two major freshwater reservoirs—Lake Mead and Lake Powell, both fed by the Colorado River—to go dry, and for the city’s water table, which has already dropped by 400 feet over the last 50 years, to descend even further. Oh well. Phoenicians will undoubtedly survive the infernal heat by doing what they’ve always done: cranking up that A.C., baby! (At least until the flow of the Colorado is reduced to a mere trickle and the hydroelectric power plants that provide Phoenix with nearly all its electricity cease working altogether.)
LAS VEGAS You’d think by now the message would have sunk in: The house always wins. But like a deluded blackjack player who knows, just knows, that his turnaround begins with the next hand, Las Vegas stays at the table, gambling away its future with ill-advised bets on sprawl and water consumption. On average, Vegas receives about four inches of water annually; 90 percent of its water comes from Lake Mead, a rapidly drying reservoir that’s fed by the already at-risk Colorado River. And even though the city has managed to cut its water use by one-third since 2002, 70 percent of the H2O Vegas uses still goes toward the watering of its lawns, golf courses, and parks. So how dry is Lake Mead getting, you ask? Fourteen years into an epic drought, its level has dropped 130 feet and is now in danger of falling below the water authority’s intake pipes, a circumstance that has compelled the agency to dig a new, lower tunnel under the lake. Meanwhile, the city continues to grow and spread: In addition to the 40 million visitors it welcomes annually, the Las Vegas Valley has seen its permanent population grow from just under 700,000 to more than 2 million in the past 25 years. Here, according to the most recent National Climate Assessment, is what all those new locals and visitors have to look forward to: a rise in temperature of 5.5 to 9.5 degrees, possibly as early as 2070, and definitely by the end of the century—meaning your grandchildren will be attending their friends’ bachelor and bachelorette parties in a place where average daytime temperatures in the summer are likely to be in the 120- to 125-degree range. Sexy!
MIAMI BEACH The warm, turquoise waters off the coast of Miami Beach have long been the stuff of escapist fantasy. But if the forecasts are accurate, in 80 years’ time the only escapist fantasies involving the city (which is technically an island) are going to be about getting the hell out, most likely via boat. Already, tidal surges regularly batter the west side every autumn during high tides; when they do, the flow of Miami Beach’s drainage system is reversed, causing a mixture of seawater and sewage to come up through street-level storm drains and flood the island. The porous-limestone foundation on which Miami Beach (and much of South Florida) sits has become saturated to an alarming degree. Harold Wanless, a geology professor at the University of Miami, believes the city can’t survive to the end of the century. Its average elevation is about 4.5 feet above sea level—which just happens to be about 18 inches below the upper-range estimate of sea level rise for South Florida by 2099. Peter Harlem, a marine geologist at Florida International University, has created a series of maps that chart Miami Beach's future as sea level continues to rise. They show that a four-foot rise will turn much of the city into a bathtub, and that a rise of six feet will effectively render most of it uninhabitable and all but destroy it economically.
MUMBAI Surrounded as it is by water on three sides, Mumbai (historically known as Bombay) has long been especially vulnerable to flooding. In 2005 rising waters killed nearly 1,500 people and resulted in losses of more than $2 billion. By 2080, according to one published study, instances of such flooding could more than double. Fully half of Mumbai’s 18.4 million residents live in slums, and nearly 3 million of them live in the zone considered to be at the highest risk for flooding; by 2070, the number of people living in the flood zone is expected to rise to 11 million. Meanwhile, scientists at the University of Hawaii have looked closely at the city’s weather patterns and concluded that by 2034, Mumbai will routinely be hotter than it has been at any time during the past 150 years, reaching what they have deemed a “point of no return.” But instead of knuckling down and preparing for the coming floods, city officials have been dragging their feet on actions that could make a difference. A massive drainage infrastructure project is now years behind schedule and millions of dollars over budget; the city has also been backsliding on its commitment not to clear local mangrove forests (which provide a natural bulwark against rising waters) and has ramped up the construction of impervious ground surfaces, which has led to a threefold increase in storm runoff.
DHAKA In Bangladesh’s capital, a dystopian future marked by climate change isn’t the future anymore. It’s the present. Climate refugees from other parts of the country—which has been hard-hit by drought, flooding, typhoons, and other extreme weather events in recent years—continue to flood into Dhaka every day, straining this city of 17 million people to its infrastructural and public-health breaking points. Today, nearly seven million residents live in makeshift slums where homes are powered with kerosene, toilets are communal, household waste is regularly emptied into the Buriganga River, and outbreaks of cholera and malaria are routine occurrences during monsoon season. The massive influx of people escaping climate-related tragedy has cruelly and ironically corresponded with a doubling of the city’s carbon emissions over the past 15 years. And the problems are only expected to worsen as the population grows: By 2025, more than 20 million people will be living within the city’s borders. What awaits them, besides the aforementioned litany of woes, is the near certainty of devastating floods: Dhaka sits just a dozen feet above sea level.
Five cities preparing for climate change so diligently that they're actually sitting pretty—sort of.
ROTTERDAM Had it done nothing else, Rotterdam would be noteworthy for giving the world climate adaptability’s first honest-to-God tourist attraction: a trio of domed, 40-foot-high pavilions that float in its harbor like a family of Bucky Fuller–designed jellyfish, suggesting an entirely new architectural model for cities built on the water. The second-largest city in the Netherlands boasts Europe’s biggest port, making its continued security one of the few things EU members seem to agree upon. Rotterdam Climate Proof, the city’s comprehensive climate adaptation plan, aims to make this low-lying port fully resilient to climate-change impacts by 2025 and to help the city maintain its status as an economic anchor for the entire continent. Organized by five areas of concern—flood prevention, adaptive architecture and infrastructure, water, quality of life for residents, and (naturally) city climate—the Rotterdam plan drives home the point that if the sea rises to its predicted level, our coastal houses may have to become houseboats, and our apartment buildings, office buildings, schools, and hospitals may have to be set afloat as well.
NEW YORK CITY Yo! You don’t just hit New York and expect it not to hit you back…hard. After Hurricane Sandy struck the Big Apple in 2012—killing dozens, displacing thousands, and causing nearly $20 billion in damage and economic losses—New Yorkers, led by then-mayor Michael C. Bloomberg, responded with a package of more than 250 initiatives to be implemented over the coming years, all designed to minimize the city’s vulnerability to coastal flooding and storm surge. Over its 438 pages, the $19.5 billion plan (titled “A Stronger, More Resilient New York”) calls for dedicating nearly three-fourths of its funding to the building and/or rebuilding of major infrastructure—but with the threat of the next major flood event factored into the design, so that homes, hospitals, water systems, subways, and the electrical grid will be able to withstand even the most punishing of future storms. That still leaves nearly $5 billion for exploring and ultimately implementing a variety of coastal flood protections, such as seawalls, armored levees, wetlands, swamplands, and sand dunes.
MEXICO CITY It wasn’t all that long ago that Mexico City was considered the worst city on earth in which to inhale. As recently as 1990, in fact, one of the city’s leading daily newspapers reported that as many as 100,000 children in the metropolitan area were dying each year as a direct result of air pollution, and that the mere act of breathing in the city—which the United Nations declared in 1992 to be the world’s most polluted—took 10 years off the lives of its citizens. As the links among carbon emissions, the urban heat island effect, and respiratory disease became more evident, the government got serious about improving air quality and reducing emissions. To the surprise of other global megacities, Mexico City managed to surpass by 10 percent its goal to curb emissions of greenhouse gases by 7.7 million metric tons between 2008 and 2012, and simultaneously to increase the number of “good air days” from an all-time recorded low of 8 (in 1992) to 248 (in 2012). The demonstrable success of these efforts has transformed Mexico City from one kind of case study into quite another—and turned its urban profile from a cautionary tale into an inspirational one.
JOHANNESBURG South Africa’s largest city had barely finished celebrating the end of apartheid in the mid-1990s when the second Intergovernmental Panel on Climate Change report turned the phrase climate change into a part of our everyday vocabulary. For a city at a major crossroads, the timing was fortuitous: Johannesburg was already engaged in a multitiered process of self-analysis, assessing its social, economic, and political futures. So why not add one more significant criterion for self-evaluation? By 2009 the city had completed a thorough climate-change vulnerability assessment, the results of which were troubling. Johannesburg appeared to be in that rare category of cities vulnerable to almost every single challenge climate change could throw at an urban area: deadly heat, massive flooding, overwhelmed power grids, an influx of climate refugees, and a lack of potable water, to name just a few. Once again, the city resolved to meet its challenges head-on. Today, Johannesburg’s Climate Change Adaptation Plan is a model for how cities can turn data into action. Its findings and goals are integrated into nearly every aspect of city planning and budgeting, so that almost no decision involving the physical city (or its citizens) is made without taking global warming into consideration, from the development of a new bus rapid-transit system that is now used by more than 50,000 people daily to a waste-to-energy project at area landfills that has cut greenhouse gas emissions by nearly 150,000 tons per year.
MELBOURNE Aussies are already accustomed to living in a country with some pretty inhospitable conditions, including the arid outback, crocodile attacks, and Sydney funnel-web spiders. But now they face a daunting panoply of climate change–related disasters as well: drought, flash floods, excessive heat, brushfires, windstorms, and sea-level rise. By 2070, rainy days in Melbourne could decline by as much as 24 percent; by the end of the century, there could be almost an extra month’s worth of days over 95 degrees, as well as a sea level rise of two feet. Even so, in Melbourne you can almost hear the cry: “Bring it on, mate. We’ll be waitin’ for ya.” With an unsurprising mix of bravado and resourcefulness, officials have risen to the challenge with the Climate Change Adaptation Strategy, a document that suffuses nearly every aspect of municipal public policy with climate awareness. On the table in the near term are new stormwater-harvest systems, a citywide cool/green roof program, an initiative to dramatically increase the city’s passive cooling efficiency, and a major effort to secure the health of Melbourne’s 70,000-plus tree urban forest—an oft-cited contributor to its status as the world’s most livable city as well as a massive carbon sink.
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