Tailored to help protect natural coastline resources, including beaches, dunes and coral reefs as well as fish and wildlife habitats, the U.S. Coastal Zone Management Act was enacted by Congress in the early 1970s. It encourages states, on a voluntary basis, to preserve and, where possible, restore or enhance these resources. The law encourages participation by making federal funds available.

Overseeing Hawaii’s participation for the past four decades, through state and county agencies, is the Hawaii Coastal Zone Management Program. Still, a new study by University of Hawaii-Manoa researchers persuasively points out that we would be foolish to assume that land use policies are rigorously safeguarding our state’s 750-mile shoreline profile.

The authors of the paper, “Failure to protect beaches under slowly rising sea level,” contend that without tougher policies and adherence to them, many of our postcard-perfect stretches of sandy coastline will thin out, shrink and eventually drown as climate change-driven sea level rise accelerates.

Sea level rise isn’t the problem by itself, though, as erosion is a never-ending challenge here. For example, without beach nourishment efforts, which date back to the early 1900s, there would be no beach in Waikiki at all.

The UH study documents a trend of beaches on a nearly 5-mile stretch of Oahu’s windward coast dwindling in size and, in some cases, disappearing after land development and the installation of coastal “hardening,” or structures including seawalls and revetments, which are sloping seawalls.

Such structures have proliferated in recent decades due to regulatory loopholes, apparent ineffective policy enforcement and a tendency to address preservation in a piecemeal manner rather than viewing regional effects. Much of the trouble is tied to agencies granting “hardship variances” that allow property owners threatened by erosion to set up a shield.

Unfortunately, that tactic can destabilize neighboring shoreline areas. Hardship variances should be reserved for properties where there’s no chance of touching off a domino effect, in which construction of a structure would likely result in neighboring property owners also clamoring to install erosion-thwarting structures.

Chip Fletcher, an associate dean and professor in UH’s School of Ocean and Earth Science and Technology and senior author of the study, said agencies tasked with safeguarding beaches in the islands have failed to track the accumulated impact of essentially armoring shorelines.

Beaches are on the losing end, in part, due to the understandable impulse to issue a seawall permit to a property owner who might otherwise see their home destroyed. In the absence of policy changes, in coming decades, as Hawaii contends with the creep of climate change, we can expect to see a steady stream of homeowners seeking hardship permits.

Another hard truth: If we continue to build seawalls in an attempt to save both private and public property, many miles of beaches will be forever lost. So, where do we draw the lines? As the state braces for the future, we need to have some tough conversations about the sorting of priorities.

Fletcher has said: “If you want beaches in the future, you’re going to have to allow the beach to migrate landward, which means that our homes are now in the wrong place, our roads are now in the wrong place.” That makes sense. But the price tag for an exit strategy that largely excludes further armoring, could be very steep.

Here’s what climate-change researchers assure us is a certainty: sea level is rising and the rate of change is accelerating. What’s uncertain is the final rate. That depends on the handling of emission scenarios and other environmental matters here and around the planet.

Earlier this year, the Hawaii Sea Level Rise Vulnerability and Adaption Report offered up a daunting forecast for the next several decades. Climbing rates of coastal flooding and erosion, among other climate-related challenges. Oahu alone could lose nearly $13 billion in structures and land edging its shorelines.

With 3 feet of sea level rise, 18 miles of the island’s coastal roads would become impassable and 13,000 residents would be displaced. Our aim must be to forge a viable shoreline exit plan in which we will not lose the state’s priceless beachfronts.

In recent years, Hawaii has rightly assembled panels to size up the future. There’s the state’s Climate Commission, representing various levels of local government. On Oahu, there’s also the Honolulu Climate Change Commission, a panel of sustainability experts that works in tandem with the city’s Office of Climate Change, Sustainability and Resiliency.

Altogether, a lot of valuable think-tank work is underway, and must continue. But county councils and state lawmakers also must take hard looks at current coastline preservation efforts. Based on the emerging picture, Hawaii is in need of policymaking changes that support priorities, including better protection for beaches, now, not later.