Climate Hotspots: The World’s Most Vulnerable Ecosystems and Cities

From coral reefs to some of the wealthiest and most beautiful islands in the Pacific, many iconic and densely populated areas around the globe are at risk due to climate change.

Beyond threatening the survival of the planet's flora and fauna, the climate crisis is also imperiling some of the world’s most visited locations and the people who live there.

Our most biodiverse ecosystems and some of our most iconic urban centers are in danger of disappearing or undergoing drastic transformations due to environmental phenomena like rising sea levels and ocean acidification.

What Will You Read About in This Article?

Coral reefs, the gardens of the sea in danger

First on our journey through climate-affected places are coral reefs, the “rainforests of the sea,” now at risk due to rising ocean temperatures and acidification. The Great Barrier Reef in Australia has lost more than half of its coral cover between 1985 and 2012.

This ecosystem is crucial not only for its biodiversity but also for the millions who depend on it for food and livelihoods. Coral reefs provide habitat and shelter for myriad marine species, from small invertebrates to large predatory fish.

Reef tourism is also a significant economic driver for many local economies. Activities such as diving and snorkeling attract millions of tourists each year, generating jobs and stimulating the economy.

The loss of biodiversity in coral reefs has far-reaching ecological and economic consequences. As corals bleach and die, they lose their ability to support rich marine life, directly impacting human communities. Additionally, coral reefs act as natural barriers, protecting coastlines from erosion and natural disasters like storms and tsunamis. Without effective climate action, we could lose this natural treasure in the coming decades.

Coastal cities on the edge of the abyss

Next, we explore coastal cities around the world. From New York to Bangkok, these cities are in a race against time. Rising sea levels, driven by melting glaciers, threaten to submerge these urban centers.

In Venice, frequent flooding has already disrupted daily life and tourism. The situation is equally dire in cities like Miami, where property and infrastructure are at constant risk from rising tides and increasingly intense storms.

The global average sea level has risen by about 17 centimeters over the past 100 years. Alarmingly, this rate is accelerating. At the end of the 20th century, the sea was rising by around 1.7 millimeters per year. However, by the beginning of the 21st century, this figure had increased to 3.1 millimeters per year due to global warming.

Today, the sea is rising at a rate of 3.7 millimeters annually. By 2050, sea levels along U.S. coasts are expected to rise between 0.25 and 0.3 meters, heightening the risk of flooding in major cities. This situation is further exacerbated by an additional issue: coastal subsidence, which is often overlooked.

“Today, the sea is rising at a rate of 3.7 millimeters annually.”

A recent study published in Nature highlights this phenomenon. Even with current coastal defenses, an additional 1,006 to 1,389 square kilometers could be at risk, affecting 55,000 to 273,000 people and 31,000 to 171,000 properties.

Boston, New Orleans, and San Francisco are especially vulnerable. Ignoring land subsidence can lead to incorrect forecasts and inadequate preparation.

Amazonia, the world's lungs under yhreat

The Amazon rainforest, often called the “lungs of the world,” is another unique region suffering from the climate crisis, largely due to deforestation. With every hectare lost, irreplaceable species disappear, and the rainforest’s capacity to absorb carbon dioxide diminishes, exacerbating the climate crisis. If the Amazon reaches a point of no return, it could transform into a savanna, losing its ability to regulate the global climate, as stated in .

Scientists report that about three-quarters of the rainforest shows signs of “loss of resilience,” reducing its ability to recover from disturbances like drought, logging, and fire. They warn that while it's impossible to predict exactly when this transition might happen, steps must be taken now to prevent it from being too late.

“If the Amazon reaches a point of no return, we could see it transform into a savanna.”

Pacific Islands, vanishing paradises

Small island nations like Kiribati and the Maldives are on the brink of disappearing. These islands face the double whammy of rising sea levels and coastal erosion, making parts of their territories already uninhabitable. The loss of these islands would mean the disappearance of unique cultures and communities and the displacement of people, known as the first climate refugees.

These individuals, forced to leave their homes due to extreme environmental factors, represent an unprecedented humanitarian and logistical challenge.

A recent example of how these places are being affected by climate change can be seen in Cartí Sugdupu, an island inhabited by the Guna people in Panama. This small enclave faces a critical situation due to rising sea levels and constant coastal erosion. The rising waters and loss of land have left the community with no choice but to abandon their home.

Just a few weeks ago, we learned about the relocation that this indigenous community had to undertake. They have been resettled on the mainland, specifically in the Nuevo Cartí housing development in the Guna Yala indigenous region facing the Caribbean. This housing complex was built by the Panamanian government to provide them with a new home.

Mekong Delta: A Basin in Crisis

Southeast Asia is another region heavily impacted by climate change. This region, specifically the Mekong Delta in southern Vietnam, is one of the places suffering the most impacts of climate change. The Mekong Delta, one of the most productive river systems in the world, faces a host of threats due to climate change and natural resource exploitation.

This region of 40,000 square kilometers and approximately 18 million inhabitants produces about half of Vietnam’s total rice crop and nearly three-quarters of its fruit, aquaculture, and fishery products. The main cause of the threats is saltwater intrusion due to rising sea levels and land subsidence, which already threaten biodiversity and the livelihoods of millions of people in the Mekong Delta.

Sundarbans National Park: A Refuge in Peril

Sundarbans National Park, which spans India and Bangladesh, houses the world's largest mangrove forest and is home to the majestic Bengal tiger. But this vast delta, encompassing nearly 100 islands, has attracted global attention for a very different reason in recent years.

Here, the effects of climate change on the lives of thousands of people and the constant flow of displaced individuals are evident. This unique place is under threat due to rising sea levels and extreme storms. Mangroves, which act as natural barriers against storm surges, are being destroyed, exposing millions of people to the risks of flooding and habitat loss.

Many men have been forced to leave the islands and seek work elsewhere because rising sea levels and saltwater intrusion make farming impossible. On Sagar, the largest and most populated island in the area, erosion is accelerating, and NASA satellite images show that the sea level has risen an average of three centimeters per year over the past two decades.

Climate change does not discriminate; it affects the most remote ecosystems as much as the busiest cities. Therefore, it’s crucial to promote actions to reduce and mitigate polluting emissions to prevent the planet’s temperature from continuing to rise. Cities must also continue taking measures to adapt to these changes, such as improving infrastructure and restoring landscapes. The fight against climate change is ultimately a fight for survival and the preservation of the natural wonders that make our planet unique.