10 Iconic Treasures Threatened by Rising Sea Levels

Increasing global temperatures and melting glaciers are leading to higher sea levels. Climate experts warn that these rising waters could submerge low-lying regions worldwide. This isn’t limited to remote areas already abandoned due to modernization. According to European researchers, some of the world’s most significant historical, architectural, cultural, and religious sites could be lost forever.

Here’s the data: Scientists at the Potsdam Institute for Climate Impact Research predict that sea levels could rise by up to 7.5 feet (2.3 meters) for every 2 degrees Fahrenheit (1 degree Celsius) increase in global temperatures. With potential temperature rises of nearly 9 degrees F (5 degrees C) by 2100, sea levels could surge by approximately 30 feet (9 meters) [source: Montaigne].

If global warming persists at its current rate, researchers Ben Marzeion from the Institute for Meteorology and Geophysics and Anders Levermann from the Potsdam Institute predict that up to 136 UNESCO World Heritage Sites could be submerged within the next 2,000 years. Although this timeframe may appear distant, many of these sites have already stood for over 2,000 years [sources: CBC News, Marzeion and Levermann]. This list includes structures ranging from remnants of a 3,000-year-old civilization to iconic symbols of American liberty, presented in chronological order.

This story is part of Covering Climate Now, a global initiative involving over 250 news organizations to enhance climate change reporting.

10: Ancient City of Nessebar

Nessebar, a city with over 3,000 years of history, is located on a rocky peninsula along Bulgaria's Black Sea coast. Originally settled by Thracians in the Bronze Age, it was later colonized by Greeks in the 6th century B.C.E. The city showcases a rich blend of archaeological and architectural treasures, including a Greek acropolis, the Temple of Apollo, a ninth-century basilica, and a medieval fortress, reflecting the diverse civilizations that once thrived here [source: UNESCO].

Despite enduring over 30 centuries of human activity and tourism, Nessebar now faces the threat of rising sea levels, which have already submerged a third of its original land. Currently, the city sits at elevations ranging from 0 to 59 feet (18 meters) above sea level [sources: UNESCO, National Institute of Immovable Cultural Heritage].

9: Venice and Its Lagoon

Venice, one of the planet's most distinctive urban landscapes, is built across 118 islands within a lagoon, interconnected by a network of canals. While Florence boasts renowned art museums, Venice itself stands as a vibrant testament to over 1,500 years of Byzantine, Gothic, and Islamic influences [sources: UNESCO, Approach Guides].

Situated at a low elevation along Italy's northeastern Adriatic coast, Venice is no stranger to flooding. However, these events are intensifying, with up to 70% of the city submerged during a 2013 flood, a trend scientists link to rising sea levels. Additionally, Venice is sinking at a rate of 0.09 inches (2 millimeters) annually, while sea levels rise by the same amount. Efforts are underway to construct seawalls to mitigate flood damage [sources: Berg, Knight].

8: Bruges Historic Centre

The 2008 dark comedy "In Bruges" highlights the Belgian town's breathtaking Gothic architecture, providing a fitting setting for a tale of two bumbling hitmen awaiting orders from their irate boss. Known as "Bruges" in English and "Brugge" in Dutch, the city's historic center is a picturesque medieval hub that played a pivotal role in the development of Flemish primitive painting. First documented in the 9th century, Bruges is home to the 401-foot (122-meter) Church of Our Lady, one of the tallest brick structures globally, which houses Michelangelo's "Madonna and Child," the only sculpture by the artist to leave Italy during his lifetime [sources: UNESCO, Codart].

With an elevation of just 10 feet (3 meters) above the North Sea, Bruges is highly vulnerable to rising sea levels caused by climate change [sources: IOP Science, Travel Journals].

7: The Island of Mozambique

The Island of Mozambique, initially settled by the Bantu tribe and later by Arab traders in the 10th century, became a key Portuguese trading hub on the route to India. Today, it is celebrated for its stunning beaches, vibrant coral reefs, and azure waters, alongside its historic fortress and religious structures. The island exemplifies architectural consistency, as its inhabitants have used the same construction methods and materials since the 16th century [sources: UNESCO, Lonely Planet].

Climate change poses a significant threat not only to the island's inhabitants and architecture but also to the marine life in its surrounding waters. For instance, sea turtles rely on specific sea temperatures to maintain a balanced ratio of male and female offspring. Rising temperatures could skew this balance, leading to a predominance of females and hindering future reproduction [sources: IOP Science, Warne].

6: Tower of London

The Tower of London, a historic fortress built by William the Conqueror in 1066, is an iconic symbol of the United Kingdom's capital. Alongside landmarks like Big Ben, St. Paul's Cathedral, and the London Eye, the Tower stands as a multifaceted structure that has served as a military base, prison, execution site, and the repository for England's crown jewels [source: PBS].

Positioned along the Thames River, the Tower was originally designed to deter invaders during the Norman conquest. Today, its proximity to sea level makes it susceptible to the impacts of climate change, as noted by researchers [sources: UNESCO, IOP Science].

5: Le Havre

Located along the English Channel in Normandy at the Seine estuary, Le Havre began as a modest fishing village before King Francois I developed it into one of France's largest ports in the 16th century. The city flourished as a trade hub until World War II, when it suffered extensive bombing [sources: World Port Source, UNESCO].

Between 1945 and 1964, Le Havre was carefully rebuilt to retain its original layout while incorporating modern urban planning and construction methods. UNESCO praised the city as a model of blending traditional and contemporary urban design.

Originally built on drained marshland, plans to elevate the city on a reinforced concrete platform 11 feet (4 meters) above ground were abandoned due to postwar shortages of iron and cement. As a result, Le Havre remains vulnerable to flooding, a risk expected to worsen with rising sea levels [sources: UNESCO, IOP Science].

4: Old Havana

Established in 1519 as the final Cuban city founded by Spanish conquistadors, Old Havana preserves much of its historic charm as a major port and military stronghold. Visitors can experience the vibrant culture of the Caribbean's largest city, with its five distinct plazas, each offering a unique atmosphere. The area is renowned for its Baroque and neoclassical architecture, including colonial mansions tucked away on quiet streets near the main avenues [sources: UNESCO, Rough Guides].

Known locally as La Habana Vieja, the old city is a hub for Cuba's finest museums and a thriving arts community. A restoration project, partly funded by the United Nations, is revitalizing the area, blending modernization with its historic allure. However, this depends on Old Havana, which sits as low as 7 feet (2 meters) above sea level in some areas, remaining above water [sources: UNESCO, Rough Guides, Tablada de la Torre].

3: Statue of Liberty

The Statue of Liberty, standing at 305 feet (93 meters) and weighing 450,000 pounds (204,117 kilograms), was a gift from France in 1886. It symbolizes freedom and democracy, greeting visitors, immigrants, and residents at the entrance of New York Harbor. The statue commemorates the friendship between France and the U.S. and celebrates the success of American democracy.

Designed by French sculptor Frederic-Auguste Bartholdi, the Statue of Liberty is made of hammered copper sheets, with a steel framework engineered by Alexandre-Gustave Eiffel, who later created the Eiffel Tower. For millions of immigrants arriving at Ellis Island, the statue was their first glimpse of America, and it remains one of the most iconic landmarks globally [source: History.com].

In 2012, Superstorm Sandy submerged 75% of Liberty Island, leaving only the Statue of Liberty and its pedestal visible [source: Rizzo]. This event offers a glimpse of the potential future if climate change predictions hold true.

2: Baha'i Holy Places

Founded in Iran in 1844, the Baha'i faith teaches that the founders of major world religions—Abraham, Moses, Jesus, Buddha, Muhammad, and Krishna—are divine messengers sent to reveal the teachings of one God. Baha'u'llah, the faith's founder, is considered the most recent of these messengers. Despite its inclusive philosophy, the Baha'i community has faced persecution, especially in its country of origin [sources: Baha'i Topics, UNESCO].

Regarded as heretics by Islamic authorities, around 20,000 Baha'is, including the prophet known as the Báb, were killed in Iran during the mid-1850s. After years of exile in Turkey, Iraq, and Egypt, Baha'u'llah arrived in Western Galilee as a prisoner in 1868. He spent the final 24 years of his life there, writing the sacred texts that form the basis of the Baha'i faith [sources: Baha'i Topics, UNESCO].

Two of the Baha'i faith's most sacred sites—the Shrine of Baha'u'llah in Acre and the Shrine of the Báb in Haifa—were built in the 1950s in present-day Israel. These shrines, along with their beautifully maintained gardens, attract thousands of pilgrims annually. However, they are at risk from rising Mediterranean Sea levels [sources: UNESCO, IOP Science].

1: Sydney Opera House

Completed in 1973 after 16 years of construction, the Sydney Opera House is a celebrated example of 20th-century architectural brilliance. Recognized as Australia's most iconic structure, it features striking white-tiled shells and glass facades overlooking Sydney Harbor [source: Australian Government].

The opera house's waterfront position makes it vulnerable to climate change. Situated just 11 feet ( meters) above sea level, its nearly 600 supporting piers face risks from rising saltwater, storm surges, increased humidity, and extreme weather conditions [source: Battenbough].