Your Favorite Ocean Beach May Be Vanishing Due To Climate Change And Sea Walls – CleanTechnica

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Last Updated on: 23rd July 2025, 10:07 am

Once upon a time, beaches had a natural defense against rising seas. The sand moved landward. Since then, natural ocean rhythms have sped up. Now researchers conclude that sea level rise is expected to cause chronic shoreline retreat, affecting over 10% of the world’s population in low-elevation coastal zones. As a result, coastal landscape management is taking many different routes. Local communities are doing all they can to ensure the protection of people and buildings from storm waves that come crashing to shore, and erecting sea walls is a common solution.

Rubble mound sea walls are often constructed along coastlines to protect inland areas and infrastructure from wave attacks and coastal flooding. Geospatial datasets derived from satellite imagery show that 33% of the world’s sandy coastline is currently hardened by structures like sea walls.

Yet when sea walls are erected to protect beachfront homes and buildings, the beach vanishes.

In the sixth century, Roman Emperor Justinian stipulated that the shorelines were open to all. Under this legal concept of common property, the tide and submerged lands were unique. No one could hold private ownership over the air, rivers, sea, and the seashore. These shoreline features were for public use, and the state was to hold them “in trust” for the people.

That idea passed into English common law and then to the US. Today, most states define the beach below the high tide line as public trust property, meaning members of the public have free access. Florida statutes, for example, describe that “the land to which the owner holds title must extend to the ordinary high watermark of the navigable water in order that riparian rights may attach.”

In Justinian’s time, global sea levels had been generally stable for at least 2,000 years. They remained that way until the 20th century, when humans started changing the planet’s climate. Climate change is not just an environmental issue — “it’s a risk multiplier,” analyzes author Weston Wilson in the newsletter We Don’t Have Time. Indeed, coastal geologists predict at least three feet of sea level rise in this century.

The dynamics of coastal geology are complex. Passive erosion occurs when rising waters meet unmoving barriers like sea walls. When one portion of a beach is built up this way, water often seeks its way around the barriers to pummel the beach down the way.

Most of the world’s sandy beaches are “likely to face severe beach loss” by 2100, the authors of a study in Nature concluded. Projects to replenish eroded beaches with pumped-in sand help to ward off the effects of rising seas. Costs are projected to increase with sea level rise and with more frequent and more severe storms triggered by climate change.

Case Study: Barcelona and Sea Walls

Storms and sea level rise driven by climate change are eroding the human-made beaches in metropolitan Barcelona, with the sea swallowing swathes of coastline every year. Coexistence with the sea here is in danger. The Boston Globe chronicled recently how climate change is threatening small coastal towns by sea level rise and intense storms — both of which erode coastlines.

Human-made coastlines are different from natural coastlines: the former erodes much faster. What happened in Barcelona to trigger such a beach loss?

Barcelona won the rights to host the 1992 Olympic Games. But at the time, its shoreline was made up of mostly rocks, breakwaters, and a few thin stretches of sand. To appeal to the soon-to-arrive Olympic visitors, the city constructed several new beaches. The city became an ideal European tourism destination.

Then the reality of a warming planet began to set in. Sea level rise, largely due to the melting of glaciers and the thermal expansion of seawater as it grows warmer, increased coastal flooding and storm surges. Storms beat down on the area’s coastline over the decades. That led to land loss.

Last year, a storm system brought waves that climbed as high as 16 feet and left parts of the nearby coastal city of Montgat virtually without a beach. Simply adding more sand wouldn’t solve the problem. After waves reached a line of beachfront houses, the decision was made to create a line of rocks that would function as a breakwater.

“What we must do first isn’t just replenish the sand but, rather, stop the loss of it,” Ramon Torra, manager of Barcelona’s Metropolitan Area, explained.

Only about one-third of the beach survived from a year ago. As a third space, the beachfront in greater Barcelona is a public place that hosts casual hangouts, fosters chance encounters, and brings families together. “The beaches are the last democratic space we have,” Montgat Mayor Andreu Absil said. “And they should be for all of us to use and enjoy all year long.”

Barcelona’s authorities estimate $70.2 million is needed to stabilize the coastline in metropolitan Barcelona’s 26 miles of coastline, 18.6 miles of which are beaches. The calculation increases exponentially when yearly maintenance costs after storms are added into the equation.

Agustín Sánchez-Arcilla, a maritime engineer at the Polytechnic University of Catalonia, said current trends show sea levels along the Catalan coast are four times higher today than three decades ago. He said it has risen by 5.5 inches in 25 years while waves are on average 11.8 inches higher.

Final Thoughts about Sea Walls

There are plenty of small armor projects around the US, too. In the tourist beach town of Matunuck, Rhode Island, workers have been building a wall and installing boulders to protect Matunuck Beach Road.

“The town paid a lot of money to put in hardening that goes down into the sand,” Bev Hodgson told the New York Times. “What they are protecting is the road and the water main.” Originally, there was a beach across the street, along with a wide ramp that led to an adjacent state beach. Today, the beach across the street is gone.

The ramp has been replaced by a footpath built over a wall of boulders. And the state beach is squeezed between a parking lot and the sea.

As humans degrade and alter the planet, sea level rise is already impacting widely different locations, like Miami, the Netherlands, Bangladesh, and the island states of the South Pacific. Each location requires a separate and regionally-appropriate adaptive response.

Ultimately, when an ecosystem is either preserved, sustainably managed, or restored to provide benefits to society and to nature, positive results occur. Nature-based solutions have been proven to consistently be a cost-effective approach to mitigating environmental hazards, including sea level rise.

An underappreciated nature-based solution for sea level rise is dunes. Dunes can make the difference in shoreline protection of coastal communities, as the mature dune creates a habitat for aeolian transported sentiment — that movement and weathering of sand particles behind and parallel to the shoreline. Interspecific facilitation, in which plants are grouped in clumps, or intraspecific facilitation, in which various plants help each other against stresses, are approaches to ensure the dynamism of young dune plantings.