Today, roughly 15% of the world’s people live within 10 km of the coast, drawn by cities and jobs. This means millions of homes, farms, and ecosystems are on the front line of erosion and sea‐level rise. For example, in November 2012, a nor’easter carved away beaches on Long Island, NY, causing severe damage to homes.
What Is Coastal Erosion?
Coastal erosion is when the ocean waves and currents wear away soil and rocks, and sand from the beach, gradually eroding the coastline. All shorelines are affected by erosion to some degree – a single winter storm or one intense hurricane, for instance, can erase dunes and barrier islands.
Even a few feet of normal erosion can be ruinous in settled land. Coastal erosion along the coasts of the United States, for example, totals some $500 million per year in lost property. Beaches and dunes — the usual protectors of storms — are dwindling.
Impacts of Coastal Erosion
Coastal erosion has severe environmental, economic and social impacts:
Environmental loss
Beaches, dunes, wetlands, and barrier islands are valuable habitats. Flooding and erosion can cover or destroy these environments. In the United States, for instance, about 80,000 acres of wetlands along the coastlines are lost each year. These mangroves, reefs and marshes protect shorelines and wildlife habitat; their loss equals diminished storm protection and wildlife diversity. Coral reefs and sandbars that help dissipate wave energy can also be damaged. Vegetation can be lost to sediment and intrusion of salinity (e.g., Bangladesh’s coastal rice paddies).
Economic loss
Land along the waterfront, terminals and facilities are incredibly valuable. Erosion, in the United States, causes around $500 million/year worth of property damage (homes, roads, etc.). Beach erosion can destroy tourism, and popular beaches decrease or disappear. For example, England’s environment agency estimates coastal erosion at risk to endanger £584 million of homes by 2100. Overseas, Bangladesh loses crops and saltwater pollution as land gets swallowed up by the sea, ruining farmers’ livelihoods.
Global risks
Coastal erosion also impacts public safety and food security. The majority of major cities (Miami, Shanghai, Kolkata, Lagos) are situated near coasts or river deltas – their success is linked with safe coastlines. If deltas erode or shrink, it can drive migration inwards or to slums, placing a burden on resources. Studies have shown that nearly half of humankind lives within 200 km of the coast, so erosion is part of global climate risk.
Climate Change and Rising Seas
Climate change is accelerating coastal erosion. Earth temperatures have risen ~1.1°C since the pre-industrial era due to greenhouse gases. Oceans absorb most of that heat and 26% of carbon emitted into the atmosphere, causing thermal expansion of seawater and melting glaciers/ice sheets. The result is global sea level has already risen ~8–9 inches since 1880, and the rise is accelerating.
IPCC scientists warn that sea-level rise and storm intensification are virtually locked in. “Coastal areas will see continued sea level rise throughout the 21st century,” causing “more frequent and severe coastal flooding in low-lying areas and coastal erosion”. They project that events like storm surges or king tides that used to occur once a century could happen almost every year by 2100.
Similarly, on the U.S. East and Gulf coasts, sea levels are already wearing away Atlantic and Gulf coastlines. National evaluations conclude that if the trend continues, tens of thousands more square miles of American coastline might wipe themselves out landward this century, threatening roads, neighborhoods and barrier islands.
Alaska’s Arctic coast is eroding at an alarming rate as permafrost thaws and waves crash over thawed terrain. Shishmaref, a village in Alaska with 600 residents, in 2016 voted to relocate as their cliffside homes were literally “melting and falling into the sea”. Such examples state climate-driven erosion has already become a reality.
Coastal Erosion – Global Case Studies
Coastal erosion is global. Here are some examples of the global reach of the problem:
United States
Erosion occurs on all U.S. coasts, but is more pronounced where development meets soft shore. The Atlantic and Gulf coasts suffer barrier islands that lose tens of meters every year. Some North Carolina barrier islands, for instance, have retreated at a 25-foot annual average rate, with individual intense storms stripping away 50 feet in a single event. The western Great Lakes have lost at similar rates. The result is colossal annual damages, approximately $500 million annually in United States property loss through erosion.
Bangladesh
This delta nation (Ganges–Brahmaputra basin) is low-lying and has been referred to as “ground zero for climate change.” Bangladesh has pushed back by building embankments and planting mangrove forests, but even so, the locals add, “we need to spend billions to lift and harden embankments and Bangladesh alone can’t do it.” The case of Bangladesh is used to describe how coastal erosion can threaten the livelihood and source of food for a nation.
United Kingdom
The UK coastline is highly erosional with many eroding soft cliffs and shingle beaches. East Yorkshire (North Sea coast) is among the fastest-eroding locations in Europe. Council reports in the Skipsea village warned that 20 houses were likely to be lost to the sea within a year. Over 21 English villages and hamlets have been officially labeled as “vanishing” – having in all nearly £600 million of property at risk. Cliffs collapsed on top of houses in recent storms in Norfolk’s Hemsby. Some British people now live in the shadow of flood and erosion risks, some actually under the threat of compulsory demolition when their beaches vanish.
Pacific Island Nations
The situation is so dire that Kiribati’s former president, Anote Tong bought land in Fiji in 2014 to serve as potential new territory if his islands become uninhabitable. Even U.S. territories are affected and on Kiritimati (Christmas Island) and the Marshall Islands, waves have breached roads and homes. These cases highlight that coastal erosion is a planetary issue – from Arctic Alaska to the equatorial Pacific, no coastline is immune.
Coastal Erosion Is a Growing Universal Concern
In short, coastal erosion is a worldwide problem since it threatens ecosystems, economies, and human lives on continents. Sea level rise and human activities are fast-tracking the problem. On the positive note, there are solutions available – from engineering to restoring ecosystems – but they require foresight, finance, and, yes, difficult choices (such as whether or not to resettle a community). The scope of the challenge is huge, but through the combination of scientific knowledge and grassroots effort and international collaboration, beach communities can forestall the worst impact of erosion and ensure that their shores will continue to be safe in the coming years.
Article by Shaloo Singh