For the last decade and a half, a great majority of policy around climate change has prioritized mitigation: regulations that hope to limit emissions, green zones in major metropolitan cities, tightened recycling initiatives, and even more acute changes such as the introduction of cleaner-running buses in New York City. But sitting quietly opposite these changes aimed at saving the world from itself are equally proactive measures that fall under a category with a far more daunting name: adaptation.

Adaptation is the notion that in some cases, the more pressing issue is adjusting all manner of daily life and business to the new landscape created by climate change, rather than focusing exclusively on trying to slow its effects. In places like Louisiana’s wetlands, for example, mitigation is no longer a viable solution. According to a report from ProPublica, the Gulf of Mexico is encroaching on Louisiana’s vast coast at the alarming rate of roughly a football field every hour. Over the past 80 years, more than 2,000 miles of wetlands have been swept into the Gulf. So while the effects of climate change may seem only theoretical in some places, others are dealing with them already—and the rest of the world can take note.

Similar tidal flooding is beginning to happen from Key West, Fla., to Portland, Maine, according to a recent study by the Union of Concerned Scientists (UCS), a nonprofit hub for research and studies to address global issues such as climate change and energy issues. Not only do these floods cause damage over time, but in severe instances, they can make areas unlivable. UCS has observed storm surges—the flooding during storms—growing more severe and beginning to leave their mark across the East Coast, particularly in low-lying, Mid-Atlantic states such as Maryland, Delaware, and Virginia. These climate scenarios have become, at the moment, inevitabilities.

In response to the record snowfall this winter, caused in part by the warming waters of the Atlantic, the Boston Globe ran an article that actually asked whether people should simply leave the city for good. Hyperbolic, for sure, but it was a sign of the times. Today’s cities are starting to think about adaptation rather than simply mitigation, says Erika Spanger-Siegfried, a senior analyst for UCS.

“Our natural instinct is to defend against the sea,” she says, “so cities and communities can decide to build seawalls to help deal with storm surge.” The solutions for tidal flooding, however, are not quite so simple. When defense does not suffice, some cities try to accommodate stormy weather: New York after Hurricane Sandy, for example, has dealt with the threat of flooding by rethinking how it organizes its infrastructure, placing critical facilities on the upper floors of buildings instead of in their basements.

But as the evidence continues to suggest that nor'easters will batter the East Coast more frequently, some cities are going further, launching design initiatives to accommodate climate change and improve the new way of living it requires. Among these programs is Boston’s Designing With Water, which embraces the notion that trying to keep water out is no longer entirely practical. By taking the city’s storm surges as a given, the project hopes to rethink its urban planning through architecture and street design with a complicated drainage system—basically, let the city flood, but decide where the flooding flows.

Designing With Water lays out the a city’s options: fortify it with walls that can withstand the rising tides, retreat to higher ground, or adapt by designing a city that can manage floods when they happen. While that program advocates for the adaptation approach, the Gulf’s steady encroachment in Louisiana has been kept largely at arm’s length with its levies—though Katrina exposed the limits of such a strategy. New York, meanwhile, has added millions of cubic yards of sand to beaches to protect its shoreline communities. But unless cities find an approach that works—and it’s likely there is no one-size-fits-all approach—they can expect to see not only the same months-long effects that followed Hurricane Sandy but, over time, the disappearance of whole waterfront communities.

“There comes a point where you can no longer retrofit to accommodate repeated water damage or when repeated storm damage is too severe,” says Spanger-Siegfried of such a future. “Short of physically elevating the entire city, the solution is to move away.”

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