Sand in the gears of climate change

For decades it’s been well understood that soft-sand beaches move — and that hard structures like concrete sea walls and stone jetties can in fact accelerate erosion. With climate change — rising sea levels and more frequent violent storms — the inevitable beach erosion and migration has only increased.

So it could have seemed like fool’s errand when the Town of Chatham’s board of selectmen recently endorsed a $750,000 “beach nourishment” program that would dredge sand from existing inlets and navigation channels to restore the town’s southern-facing beaches, which are among its main assets. But the town’s actions are well considered and have become standard conservationist practice, using what environmentalists call “sacrificial beaches and sacrificial dunes” as a bulwark against rising tides and storm surges.

A bill before the Legislature could make Chatham’s program and others like it part of a larger coordinated state effort to protect the Massachusetts shoreline. Called the Comprehensive Adaptation Management Plan, the bill (which has been passed by the Senate and is now before the House Ways and Means Committee) would establish an interagency advisory committee, a set of best management practices and adaptation strategies for cities and towns along the Commonwealth’s 1,500-mile shoreline, vulnerability studies to assess the impacts of climate change, a regional grant program to assist local communities, optional buybacks for properties located on threatened beaches, and emergency action plans for storms and floods. The bill essentially expands on Governor Baker’s 2016 executive order establishing a climate-change strategy for the state and codifies it as state law, ensuring that the state will have a clear climate plan beyond the length of the governor’s term of office.

The law presents reasonable options for property owners on threatened shorelines, like the perpetually battered Plum Island. Properties bought by the state would subsequently be prohibited from future private development and converted to public use as conservation areas.

“The beaches are moving,” says Jack Clarke of Mass. Audubon, one of the groups behind CAMP, “and anything put on top of those beaches has to be moved with them.” That statement takes a common-sense approach to the inevitable. That’s why the National Park Service, which administers the Cape Cod National Seashore, has allowed the sea to take back large chunks of the asphalt parking lot at Herring Cove Beach in Provincetown without replacing it. And why they have replaced the former concrete bathhouse and snack bar with semi-permanent structures that are not only further back from the shoreline but also moveable.

But there’s another reason behind the restoration of what are known as barrier beaches — they serve not only seasonal recreation, but also shield the lands behind them from storm surges. Barrier beaches by definition are those that protect wetlands, marshes, and estuaries, which in turn protect land further inland. That’s one of the reasons why the Trustees of Reservations, the nonprofit that owns Crane Beach in Ipswich, years ago began planting beach grass over its acres of white dunes. Every year, the shape and size of Crane Beach changes, but the dunes continue to protect the Great Marsh behind it, with its vast network of wetland and estuaries — and the town beyond.

The Trump administration, with its rejection of the Paris Accord, among other actions, has signaled its indifference to climate change, which is yet another reason state and local government has to step up. As advocates have rightly argued, the long-term impacts of climate change — from Plum Island to the Seaport District — have to be met with long-term planning. The House should move to pass the CAMP bill as swiftly as possible.