In many parts of the world, beaches are where humans feel closest to nature. People walk barefoot on warm sand, inhale the salty breeze, listen to the rhythmic crash of waves, or simply lose themselves in the quiet vastness of the sea’s horizon. Yet this beauty—long perceived as timeless—is now facing a threat unlike anything seen in modern history. A series of recent scientific studies warn that nearly half of the world’s sandy coastlines could disappear before the end of this century. These warnings do not stem from speculation or poetic alarmism, but from rigorous analyses combining decades of satellite imagery, field measurements, and coastal geomorphology.
At the FAPESP–Uruguay symposium, marine scientist Omar Defeo emphasized that “nearly half of all beaches will disappear by the end of the century.” His statement reflects a growing body of research showing that coastal erosion is no longer a local or isolated issue; it has become a rapidly accelerating global phenomenon driven by climate pressures and human activity. Similar conclusions are echoed in numerous international studies, including two landmark papers that now serve as essential scientific references for understanding this crisis.
World’s Sandy Beaches in Danger
One of the most significant studies sparking global concern is the article “Sandy coastlines under threat of erosion,” published in Nature Climate Change in March 2020 by Michalis I. Vousdoukas and his research team. Using 35 years of satellite data and climate simulations extending to the end of the 21st century, the team estimated that without serious mitigation efforts, almost 50 percent of the world’s sandy beaches could vanish by 2100.
“What we find is that by the end of the century around half of the beaches in the world will experience erosion that is more than 100 metres,” Vousdoukas said, underscoring the unprecedented scale of the threat.
Under strong mitigation scenarios, the study notes that up to 40 percent of that projected loss could still be prevented—if global emissions are reduced and coastal adaptation policies are broadly implemented.
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A second major study reinforcing these findings comes from the international research titled “Global patterns in sandy beach erosion: unraveling the roles of anthropogenic, climatic and morphodynamic factors,” published in Frontiers in Marine Science in 2023, led by Fabio Bozzeda, Leonardo Ortega, Leonardo Lopes Costa, Lucia Fanini, Carlos A. M. Barboza, Anton McLachlan, and Omar Defeo. The researchers collected in-situ data from 315 sandy beaches worldwide and combined it with satellite observations of sea pressure, wind patterns, and sea-level variations.
Their analysis revealed that beach erosion is not driven solely by sea-level rise, but by a complex interaction of climatic forces, human impact, and local physical characteristics. More than one-fifth of the investigated beaches showed intense, severe, or extreme erosion—highlighting that the crisis is unevenly distributed and forms geographic hotspots.
The biggest driver of erosion is rising sea levels caused by climate change. As the sea rises, incoming waves reach further inland, delivering greater energy and pushing the shoreline backward. This process is amplified by regional variables such as atmospheric pressure anomalies, seasonal wind patterns, wave heights, and sea-level fluctuations. Local factors—including beach slope, sand composition, width of the sandy zone, and tidal ranges—determine how vulnerable a beach is. Narrow, steep beaches, for example, are far more fragile; their morphology cannot absorb wave energy effectively, leading to rapid erosion even with minor sea-level increases.
Human Activity Make it Worse
Human activity has made this situation worse. Development along coastlines restricts the natural movement of beaches, creating what scientists call coastal squeeze—where beaches are trapped between rising seas and fixed infrastructure on land. Hotels, seawalls, coastal roads, and sand mining all accelerate the destruction of dunes and natural buffer zones. Without vegetation and healthy morphological systems, beaches lose their ability to regenerate, allowing erosion to progress even more quickly.
Global satellite data from 1984 to 2016 shows that more than one-fifth of the world’s sandy beaches have already been eroding at rates exceeding half a meter per year. If current trends continue, not only ecological systems but also social and cultural structures dependent on beaches will be at risk. Beaches are vital habitats, turtle nesting grounds, natural storm barriers, sources of livelihood through fisheries and tourism, and anchors of coastal cultural identity. Losing them means losing ecological legacy and cultural heritage built over generations.
Together, these two major studies show that the world’s coastal crisis cannot be addressed simply by monitoring the damage. Scientists emphasize the need for ecosystem-based adaptation strategies, including dune conservation, protection of coastal vegetation, restrictions on development in highly vulnerable zones, and an end to sand mining along shorelines. In the long term, the global effort to slow climate change will determine whether half of the world’s beaches can still be saved.
Beaches are not merely tourist destinations; they are living systems that sustain biodiversity, culture, and human safety. If the world fails to act decisively, future generations may know many of today’s coastlines only through old photographs and fading memories. Coastal erosion is not just a natural process—it is a reflection of humanity’s failure to protect the spaces where life begins and endures. Beaches may appear eternal, but scientists warn: without drastic change, these sands could vanish far sooner than we imagine. (Sulung Prasetyo)
