Coastal Cities Fight or Flee as Sea Levels Rise

With global sea levels expected to rise an average of one to four feet by 2100, cities like San Francisco, Manila, and Boston are set to become case studies in how urban planning decisions will create varying impacts across economic classes in an increasingly watery world.

In a recent comparison of how San Francisco Bay and Manila are responding to the dangers of sea level rise, the New York Times says the fate of the inhabitants of these world cities depends “mostly on the accident of your birth: whether you were born rich or poor, in a wealthy country or a struggling one, whether you have insurance or not, whether your property is worth millions or is little more than a tin roof.”

And then there are the errors of history in both cities. “Climate change has magnified years of short-sighted decisions,” reports the Times, with Manila “allowing groundwater to be pumped out so fast that the land sagged and turned into a bowl just as the sea was rising,” and the Bay Area permitting people “to build right at the water’s edge, putting homes, highways, even airports at risk of catastrophic flooding.”

Yet, as the water rises, “people tend to hold on, often ingeniously,” the Times notes. In the Bay Area, such tenaciousness owes to the high value of property. Manila’s most vulnerable, by contrast, fight to remain in place “because they have so little that they have nowhere else to go.”

The cities are also taking different approaches to the problem. For the wealthy inhabitants of the Bay Area, the answer thus far has been to “armour” the coastline with seawalls. A recent vote approved a US$425-billion bond measure to help fortify one seawall, the Embarcadero, which currently protects “some of the city’s most expensive real estate,” as well as “a subway line, a light rail tunnel, and part of the city’s sewage infrastructure.”

Other measures include a $587-million allocation to raise the seawall around San Francisco’s airport, which was built on tidal marshlands.

That so much of the city is built at the high tide line is creating major headaches for many policy-makers in the Bay Area, as they are increasingly forced to navigate the political minefield of advocating for a “managed retreat”. Community coffers rely on property taxes, so “forcing people to move away would punch holes in city budgets,” writes the Times. “And anyway, who would pay to buy out homeowners?”

An unmanaged retreat, however, is hardly an option. The Times points to a recent case in which 52 tenants of a building threatened by the collapse of a seawall were forced to move, with zero compensation. “Are we going to decide by not deciding, and wait for the water to reach our doorsteps?” asked San Francisco Supervisor Aaron Peskin.

In Manila, meanwhile, 14 million people face a rapidly worsening situation. The Times reports that sea levels there are rising “much faster than the global average,” while “a proliferation of fish ponds and the rapid extraction of groundwater” has been dragging ground levels lower.

“A large part of Metropolitan Manila is facing more water-related impacts because of decades of myopic, cross-eyed land use planning,” said Renato Redentor Constantino, executive director of the Manila-based Institute for Climate and Sustainable Cities. While the Bay Area coastline is lined with million-dollar mansions, in Manila it is the city’s impoverished millions who have no choice but to build their lives “in hazardous, low-lying areas that are already lashed by tropical storms.”

Fleeing—and leaving behind livelihoods, transportation networks, and health systems—is no path to security, said Redentor Constantino, but others think there may not be a choice. “You need some sort of rational, organized retreat from the coast,” said Antonia Yulo-Loyzaga, a board member at the Manila Observatory research group. “There’s no option unless you want people to live in constant fear,”

Back in the U.S., Boston is emerging as a leader in its fight against rising sea levels, reports the Washington Post. “Ranked the world’s eighth most vulnerable to floods among 136 coastal cities by a 2013 study produced by the Organization for Economic Cooperation and Development,” low-lying Boston is making some tough decisions fast, and making them “at a relatively affordable price.”

In the face of ongoing ocean creep, Mayor Marty Walsh “has vowed to spend more than $30 million a year, equal to 10% of Boston’s five-year capital budget, to defend the city from a watery future,” the Post writes. In the works are street-raising, berm building, and portable metal “aqua fences”.

No such feats of engineering will be available for Boston’s poorest residents. But neither will they be left running ahead of the tide—at least not if some policy-makers have their way.

“Your most vulnerable citizens are more likely to bear the burden of climate change disproportionately,” said Christopher Cook, Boston’s chief of environment, energy, and open space. “So if we don’t provide climate adaptation plans, you’re doing more of our people a disservice.”