Coastal Crisis: Nearly Half of the World’ Beaches Could Disappear by 2100
Global climate change and expanding human development along coastlines are driving a rapid collapse of beaches — and scientists warn that nearly half of the world’s sandy shores may vanish by the end of this century.
The loss is being fueled by a phenomenon known as “coastal squeeze,” where rising sea levels combine with urbanization and infrastructure encroachment on coastal zones.
Coastal zones typically comprise three interlinked regions:
The dune (post-beach) — sand ridges above the high-tide mark shaped by wind;
The beach face — the sandy stretch exposed during low tide and covered during high tide;
The foreshore / submerged zone — the underwater region where waves break.
A healthy beach ecosystem depends on a continuous exchange of sand: wind carries sand from dunes to the surf zone, and waves push sediment back toward the beach. 🌊 But as urban development destroys dunes or interrupts this natural exchange — for example by building directly on sand or using mechanical cleaning — the entire system becomes destabilized.
Consequences: Environmental, Economic and Social
Ecosystem Collapse: The disruption harms biodiversity. Species that thrive in sandy and submerged zones — from invertebrates to fish — decline sharply when the natural sand exchange is disturbed.
Loss of Livelihoods: Communities relying on fishing and tourism suffer as beaches shrink and marine habitats vanish.
Increased Risk to Coastal Cities: Without natural buffers like dunes, coastal cities become more vulnerable to storm surges, flooding, and encroaching seas — endangering infrastructure, homes, and lives.
At a recent symposium in Montevideo (FAPESP Day Uruguay), marine scientist Omar Defeo sounded the alarm: “Almost half of the beaches will disappear by the end of the century.”
He emphasized that protecting coastal zones — dunes, beaches, and submerged areas alike — must be a priority. Coastal nations need to collaborate on conservation, sustainable development, and policies that prevent destructive building on vulnerable shorelines.
