Sea Change

Today, the Everglades are a tangle of sopping jungle alive with crocodiles, panthers, manatees, and bright-pink spoonbills. By 2100, large swaths of these forests will instead by miles of sea. Today, Cape Hatteras National Seashore harbors some of the East Coast’s most beloved beaches, packed with shorebirds, shells, and generations of visitors. By 2100, many of these barrier islands will be underwater, with only their tips poking above the waves.

The National Park Service knows that rising sea levels will dramatically alter many of the parks. What the agency doesn’t know is precisely how. Two years ago, the problem caught the eye of a Park Service visiting scientist Maria Caffrey, an energetic London-born climatologist. Caffrey realized that most of the existing climate-change data are global, national, or regional, but to know what to expect in the coming decades, the parks needed local information. She also realized that she was the one who could provide those important details.

In August 2013, Caffrey and a cadre of graduate students at the University of Colorado embarked on an ambitious three-year project that will provide 117 coastal Park Service units with detailed storm-surge and sea-level projections. The team is crunching disparate data from the Intergovernmental Panel on Climate Change, National Oceanic and Atmospheric Administration, and the U.S. Army Corps of Engineers, and will assemble local scenarios for the years 2030, 2050, and 2100. For a few particularly vulnerable Park Service sites, including Cape Canaveral National Seashore, Caffrey also will create high-resolution models that can simulate details down to the movement of sand dunes or the loss of vegetation.

“This will give the Park Service early warnings about important structures like lighthouses or other cultural or natural sites that might be right in the line of fire as far as climate change goes,” says Caffrey.

Already, the team has discovered staggering differences between parks. In parts of Louisiana, for example, the sea level is climbing faster than in any other part of the country—about a third of an inch per year and potentially 7.62 feet by 2100. But in parts of Alaska, such as Skagway and Sitka, relative sea level is actually decreasing—and could fall by more than six feet by 2100. (The reason: Land rises as heavy glacial ice disappears. Eventually, sea level in that area will switch course and start creeping up, which makes strategizing particularly complicated.)

Other coastal areas will suffer less from sea-level rise and storm surges than from secondary effects. Saltwater intrusion, for instance, could damage centuries-old artifacts buried in some of the nation’s first settlements at Colonial National Historical Park in Virginia.

Identifying the likely projections and challenges for each Park Service site will help managers prepare, adapt, and even decide where it might be best to let nature take its course.

“We don’t have unlimited funding, and we will have to make hard choices,” says Rebecca Beavers, the coordinator for coastal adaptation to climate change for the Park Service. “It’s really helpful for us to get baseline data so we can consider the context of locations in terms of what strategies may be best. We’re not going to be moving the Statue of Liberty.” (But managers have begun planning for possible flooding by bolstering docks and raising utilities such as electrical panels.)

While Lady Liberty may not move, the Park Service has made dramatic preparations in other parks. In 1999, the agency moved the 4,830-ton Cape Hatteras Light Station nearly 3,000 feet inland to protect the 130-year-old structure from shoreline erosion. In the wake of Hurricane Sandy, which damaged nearly 50 historic structures in the Sandy Hook area of Gateway National Recreation Area, managers are strengthening buildings for future floods and moving boilers out of basements. They’re also tearing down one cafeteria. Instead, food trucks, which can quickly evacuate during storms, will sell meals to beach-goers.

Park Service staffers are also considering putting in ferries where roads may be submerged in parks like Gulf Islands National Seashore. In other areas, they are building structures that can be dismantled before a storm and easily rebuilt later. In Assateague Island National Seashore, for example, instead of constructing an asphalt parking lot, staffers laid a clay base with crushed oyster shells, which is easy to rebuild as the dunes naturally shift. (And when damaged, the materials don’t harm the environment.) In the Everglades, planners recently tested structures called eco-tents, which can accommodate visitors during periods of high visitation and can be dismantled during hurricane season.

“We can be an agency to lead by example, but we have to be willing to try new things,” says Beavers. “We recognize that not everything will work as planned, but those are important lessons to learn as well.”

By August 2016, Caffrey will deliver a hefty report to the National Park Service, which will include suggestions for policymakers and details that will help park managers make decisions ranging from where to build a dock to how to protect nesting sites of the endangered piping plover along the Eastern Seaboard.

Although much of this work will remain out of the public eye, visitors may notice the fruits of Caffrey’s research at Biscayne, Dry Tortugas, Everglades, Golden Gate, and Point Reyes. Within the next year, in at least one busy location within each park, visitors will spot poles with colorful balls marking the expected sea-level rise in the years 2100 and 2300, which will top 11.5 feet in some places. The balls may be a sobering sight, but perhaps they will also be a source of hope: With new research, we will become better informed and better equipped to adapt to a changing world.