Climate change is directly impacting the overall development of humanity. Around the world, many countries and territories are being placed on red alert due to the effects of climate change. The country of Kiribati, along with other Pacific island nations, is among the first to experience the consequences of climate change. Along with this, many cities in numerous countries are also threatened with gradual submersion and disappearance from the world map, especially in Asia.
These cities are vulnerable for many reasons, including their low elevations and frequent exposure to tropical storms accompanied by winds and heavy rains that cause flooding. Climate change is also causing the melting of ice in both poles, leading to changes in many weather patterns, increasingly severe storms, and irregular seasonal shifts.
So, which cities in the world are currently at risk of being submerged by the ocean? Let’s explore this issue together with The Wise Goat.
What is Climate Change?
Climate change is a term used to describe the alteration of the climate, partly caused by human activities that change the composition of the Earth’s atmosphere. This change, combined with natural fluctuations, has resulted in variations in the climate over time. Simply put, climate change refers to the modification of the climate system, including the biosphere, atmosphere, hydrosphere, and lithosphere, in the present and future.
Causes of Climate Change
Global climate change is caused by two main factors: objective and subjective causes. According to studies by scientists, human impacts on the natural environment are the main cause of climate change. The increase of CO2 emissions from industrial production, deforestation, water usage, and other harmful gases are the reasons for this situation.
In addition, there are objective factors, including changes in the internal nature such as changes in the activity of the sun, the Earth’s orbit, the movement of continental plates or submarine earthquakes, which have also had significant impacts on climate change.
Rising Sea Levels
Climate change has been causing many negative impacts such as ecosystem destruction, loss of biodiversity, war and conflict, disease outbreaks, and most importantly, rising sea levels. Rising sea levels are one of the consequences of climate change. The average sea level has risen about 23cm since the 19th century. Over the past 25 years, sea levels have risen by 7cm, and it is projected to rise by an additional 3.2mm each year globally. According to the latest data from the US National Oceanic and Atmospheric Administration, sea levels are expected to rise more in the next 30 years than the entire 20th century. The changes in sea levels are related to two main factors.
The first factor is global warming. When the global temperature is high, it will cause the temperature of the ocean to increase. The rise in sea levels over the past 25 years is partly due to warmer oceans.
Second, the ice in the Arctic and Antarctic is melting rapidly. Rising temperatures cause giant ice sheets covering areas to melt faster, especially in the two polar regions. According to NASA and the Ice Sheet Mass Balance Inter-comparison Exercise, the ice in the Arctic is melting at an astonishing rate, faster than what scientists had predicted. From 2018 to 2021, through monthly satellite data, scientists from the Jet Propulsion Laboratory at the California Institute of Technology and the Applied Physics Laboratory at the University of Washington in the US found that the ice in the Arctic had thinned by 1.5m during this time.
From 2005 to present, the total amount of ice lost in the Arctic is 447 billion tons per year. This is equivalent to 14,000 tons of water pouring into the sea every second. Previously, during the period from 1986 to 2005, the estimated amount of ice melting was about 5,000 tons per second. Therefore, it can be seen that the rate of ice melting in the Arctic from 2005 to present is happening very quickly and is almost three times faster than the period from 1986 to 2005.
The speed of melting in the Antarctic, according to a new study published in the journal Nature, poses a risk of rapid and uncontrollable sea level rise due to the melting of large ice sheets in the Antarctic caused by the current global warming. The study warns that if greenhouse gas emissions are not rapidly reduced, the world will face a sudden increase in the speed of melting in 2060. This will cause sea levels to rise and threaten most coastal cities around the world.
It is predicted that by 2100, the limit in the Antarctic will be activated if the global temperature increases by 3 degrees Celsius compared to the pre-industrial period. But if the world can meet international commitments, the amount of melting in the Antarctic will only cause sea levels to rise from 6 to 11 cm by the end of the 21st century, equal to the current rate of melting. Scientists have also issued many warnings about the amount of melting in the Antarctic. Specifically, if all the ice blocks in the Antarctic melt, it will cause the global sea level to rise by 57m and completely submerge the Pacific island nations and parts of continents around the world.
Due to the increasing rate of melting, the phenomenon of sea level rise is becoming more and more apparent, causing many serious consequences such as increasing floods in coastal areas, loss of fertile land, increasing areas of saltwater or brackish water intrusion, loss of biodiversity of important ecosystems, and the disappearance of cities.
So which cities are currently threatened with submergence by rising sea levels? The number is very large and includes most cities and villages located at an elevation of only a few tens of meters above sea level, which are also densely populated areas. However, here are the top 9 cities currently at risk of submergence according to Google Atlas.
Top Cities Sinking Fastest Into The Sea
9 – Ho Chi Minh, VietNam
In ninth place is Ho Chi Minh City, Vietnam. Ho Chi Minh City is located in the Southeast region of Vietnam, with an area of 2095 km², and is one of the five centrally governed cities of Vietnam. Although the city’s coastline is not very long, it is quite winding, with a length of about 25 km. Ho Chi Minh City is located in a tropical monsoon climate zone, with high temperatures throughout the year and two seasons: the rainy season and the dry season.
The rainfall here is quite high, ranging from 1,500 to 1,900mm. The average annual temperature ranges from 25 to 30 degrees Celsius, rarely dropping too low or rising too high. In general, the climate of Ho Chi Minh City is quite mild compared to the Central and Northern regions, and extreme weather phenomena such as typhoons or tropical depressions are rare. The terrain of the city is in a transitional region gradually sloping from the North to the South.
Geologically, Ho Chi Minh City is mainly composed of two sedimentary layers: the Pleistocene and the Holocene. The Pleistocene sediment is mostly found in the northern, northwestern, and northeastern parts of the city. It is a type of ancient alluvial sediment formed through the process of sedimentation and weathering over a long period of time, so the soil in this area is quite solid. The Holocene sediment in Ho Chi Minh City has many origins, such as the sea, estuaries, rivers, and marshes, and is mostly concentrated in the eastern and southern parts of the city. Since it was relatively recently formed, the soil in this area looks weak and is not suitable for high-rise constructions.
Due to the urbanization process and climate change, Ho Chi Minh City is currently sinking faster than any other city in the world in relation to sea level. In Southeast Asia, Ho Chi Minh City is sinking at a rate of 16.2 mm per year, about four times faster than Jakarta, Indonesia, which is sinking at a rate of 4.4 mm per year. Groundwater exploitation is the main cause of this phenomenon. At the same time, the large number of high-rise buildings concentrated in areas with weak soil, such as District 2 and District 7, exacerbates the problem of subsidence. Moreover, currently 40 to 50% of the city’s land area is located at a height of 0 to 1m above sea level, 15 to 20% is at a height of 1 to 2m, and very few places are above 4m above sea level.
Sea level in the Ho Chi Minh City area is increasing by 2.2 to 2.5 mm per year. Therefore, combined with subsidence and rising sea levels, by 2030, the Ho Chi Minh City area will sink by about 15cm. And in the not-too-distant future, it will not only be the District 7 area, but many other areas in Ho Chi Minh City that will be flooded due to high tides.
If the sea level rises to 100cm, about 17% of the area in Ho Chi Minh City is at risk of being completely submerged.
8 – New Orleans, Louisiana, USA
In 8th place is the city of New Orleans, located in the southeastern part of the state of Louisiana, USA. With an area of 906.1 km² and a population of around 390,000 people, it is the most populous city in Louisiana and the 12th most populous city in the Southeastern United States. Serving as a major port, New Orleans is considered the economic and commercial center of the state.
New Orleans is situated in the Mississippi River Delta with an average elevation currently ranging from 0.3 to 0.6 meters below sea level. However, few people know that this city was once situated higher than sea level. For thousands of years, the Mississippi River has transported a large amount of sediment deposited in the northern plain during the last ice age. This sediment has flowed into the Gulf of Mexico, part of which has been retained, and over time enough sediment has accumulated to create an area of land now known as New Orleans.
This land was continuously raised above sea level as sediment from the Mississippi River flowed into it each spring. At that time, the entire city of New Orleans was situated above sea level. However, this was no longer true by the 18th century. At this point, although 100% of the area of New Orleans was still above sea level, the majority of the land area was low-lying wetlands. As the city became more densely populated, the government began to develop various methods to reclaim the city’s wetlands. From there, the wetlands began to be drained and dried, and houses and businesses were continuously built, and everything began to change.
By 1895, 5% of New Orleans’ land was below sea level. By 1935, nearly 30% of the city was below sea level, and today, over half the city lies lower than sea level. The process of building and reclaiming swamp land inadvertently caused subsidence, as sediment settled out of the ground. Typically, sediment would continue to be replenished from upstream sources, as sediment-laden waters from the Mississippi River flowed into the delta. But humans have interrupted this sediment deposition process by building dams and levees along the river to prevent flooding, preventing the river from continuing to build up the land.
In 2005, Hurricane Katrina hit New Orleans, destroying almost all of the city’s levees, canals, and flood walls. The hurricane caused heavy damage, submerging many areas of the city and forcing around 90% of New Orleans’ population to evacuate to safety. Today, New Orleans is sinking at a rate of about 2mm per year, while sea levels are rising due to global warming, making the city increasingly vulnerable. Therefore, city officials need to continuously monitor and innovate their approach to climate change, as well as reinforce levee and floodwall systems to ensure the safety of residents.
7 – Kolkata, West Bengal, India
The 7th position is held by the city of Kolkata, also known as Calcutta, which is the capital of the Indian state of West Bengal. The city is located in eastern India, along the banks of the Hooghly River, with an area of 206 km² and a population of over 5 million people. Kolkata has a tropical climate, with an average annual temperature of 27°C. During the hot and humid summers, temperatures often exceed 40°C, while winters are mild, with temperatures ranging from 12 to 14°C. Typically, at the beginning of summer, dry gusts of wind accompanied by thunderstorms and heavy downpours relieve the heat. The city’s average annual rainfall is from 1,000 to 1,500 mm.
The city is situated in the Ganges River delta, with an elevation ranging from 1.5 to 9 meters above sea level. Much of Kolkata was originally a vast wetland, which was drained and filled over many centuries to provide housing and infrastructure for the growing population. Like most places in the Ganges River basin, alluvial soil predominates in Kolkata. The fourth-period sedimentary layers consist of clay, silt, multiple layers of sand, and gravel under the city’s soil. These sedimentary layers are sandwiched between two lower layers of clay with heights ranging from 250 to 650 meters and an upper layer ranging from 10 to 40 meters. Thus, in general, the city’s soil is quite weak.
According to Indian seismic standards, the city falls under seismic zone 3 on a scale ranging from 1 to 5, where 5 is the highest level. In terms of tropical cyclones and tornado zones, the city is in a high-risk area for destruction. Due to high population density, non-uniform construction and planning, and the difference in height between the high and low tides, the situation in Kolkata is becoming increasingly severe. In particular, poor residents are facing natural disasters in this city. Many experts predict that the city is sinking, and it could reach a level lower than the sea level by 2030. At that time, the riverside and low-lying areas will be submerged. The Indian government is currently under pressure to monitor and implement integrated measures to prevent climate change in this city.
6 – Georgetown, Guyana
In 6th place is Georgetown, the capital and largest city of the Cooperative Republic of Guyana. Located on the Atlantic coast near the mouth of the Demerara River, Georgetown covers an area of 70 km² and has a current population of about 150,000 people. The city is known as the “Garden City of the Caribbean” for its historic and lush British architecture. It is the country’s largest administrative and financial services center.
Georgetown has a tropical rainforest climate with a wet and dry season. The city’s temperature is regulated by the northeast trade winds blowing in from the North Atlantic, so temperatures rarely exceed 31 degrees Celsius. Georgetown does not have a true dry season as rainfall is above 60mm every month. The city is situated on a coastal plain, surrounded by swamps and grasslands to the east and south. Its elevation is only about 1 meter above sea level, so the city is protected by a seawall called the “Sea Defense Wall” to prevent large waves from flooding the city. In addition, Georgetown has a network of canals and reservoirs to drain water within the city. As a slowly developing country, Guyana has preserved vast areas of tropical rainforest, which helps regulate the climate. According to recent statistics, less than 1% of the country’s trees have been cut down.
Despite its good environmental record, Guyana, particularly the capital Georgetown, is increasingly vulnerable to sea-level rise. Unlike cities inland, coastal cities like Georgetown are directly affected by the sea-level rise. According to experts, the sea level in the Caribbean region is expected to rise by an average of about 22 cm in the next 30 years. If the world continues to burn fossil fuels at an increasing rate, sea levels could even rise continuously and exceed human predictions by the end of this century. Georgetown has protected itself with a 450km sea defense wall to withstand storms. However, according to the IPCC – the Intergovernmental Panel on Climate Change, the scenario of Georgetown sinking within the next 10 years is entirely possible.
5 – Basra, Iraq
Ranked fifth is the city of Basra, also written as Basrah. This is the capital city of Basra Province, Iraq, located on the banks of the Shatt al-Arab river in southern Iraq. The city covers an area of about 181 square kilometers and currently has a population of around 1.5 million people. Basra is situated in the lowest region of Iraq with a relatively flat terrain sloping gradually towards the sea. The low-lying plain has given rise to unique marine and riverine ecosystems, distinguishing this area from other regions to the south.
This is also a place with many water features, including swamps, rivers, and canals. The city of Basra has a hot desert climate similar to the surrounding areas. However, this region receives more rainfall than other localities in inland Iraq. During the summer months, Basra is one of the hottest cities on the planet with temperatures often reaching 45 degrees Celsius. The highest temperature recorded in this city was 54 degrees Celsius in 2016, second only to Khasab (Oman) and the Death Valley in the United States.
The coastal area of the city is only at an elevation of 0.5 meters above sea level. Therefore, it is at risk of being submerged as sea levels continue to rise due to climate change. Although not subjected to tropical storms like some other places, scientists predict that Basra may be partially or even completely submerged within the next 10 years.
4 – Amsterdam, Netherlands
In fourth place is a city in the land of tulips, Amsterdam. Amsterdam is the capital and most populous city of the Netherlands with a population of around 922,000 people. It covers an area of 219.32 km², located in the province of North Holland and is often referred to as the Venice of the North due to its extensive network of canals. The terrain of Amsterdam is very flat, partly formed from reclaimed land, so the city lies about 2m below sea level. In the past, the Netherlands, in general, and the capital city of Amsterdam, in particular, have experienced numerous major floods causing serious damage, leading them to gain a lot of experience in water management.
The country of tulips has developed systems of sand dunes, embankments, canals, and coastal barriers. All of these have made the Netherlands and Amsterdam always on or most balanced with the sea level. But there have still been many historic floods that submerged tens of thousands of people, livestock, homes, cars, as well as other buildings and architectural structures. The Dutch have worked hard to keep their capital above sea level. In the Dutch government, there are 27 councils specialized in water management. These councils are fully responsible for managing water and the water management system. Members of the councils regularly check the water level. If necessary, they also adjust the level by pumping water into higher-lying canals. Sometimes they also pump it out into rivers that flow straight into the sea. The entire extensive water management system keeps the Netherlands safe.
However, the new layers of soil on the surface are gradually drying out, causing land to sink faster than expected, making a part of Amsterdam lowering faster. This requires the Netherlands, in general, and the city of Amsterdam, in particular, to cope with climate change more quickly, as melting ice sheets are raising sea levels, posing a threat to the water management structures of this country. The Dutch National Geographic and Information Center has declared that this country and its capital city of Amsterdam are sinking faster than previously estimated.
The worst-case scenario in the coming years is that the entire territory of this country will be completely submerged under 2m below sea level. The land of tulips and the famous city in Europe with its nightlife are facing more serious threats than we think. For nearly a century, Amsterdam has been mainly maintained by the city’s system of flood barriers. But despite the relentless efforts of leading flood prevention scientists and experts, Amsterdam still faces the risk of severe flooding in less than 10 years. The country’s system of dikes, dams, and drainage systems must be closely monitored and constantly upgraded in the coming years.
3 – Venice, Italy
In third place is the city of Venice, also known as “the city of canals”. It’s called this because Venice was built on an island with 118 islands formed by 150 canals and a shallow lagoon. These islands are connected by about 400 bridges. Venice is located in northeastern Italy and has a population of about 259,000 people.
The gentle waterways that flow around the buildings have long been a beautiful sight for many international tourists. Venice is a very famous tourist destination, a major cultural center, and has been ranked as the most beautiful city in the world several times. But if you love Italy, you may be very sad to hear that Venice is at risk of being submerged by floods and high tides in the near future. Venice is sinking about 2mm per year. In 2018, the Lagoon canal was hit by a series of severe storms, causing the worst flooding in a decade, with record high water levels.
In 2019, 90% of Venice was flooded and the situation is getting worse due to coastal erosion. The flood barrier was designed in 1980 and construction began in 2003, but it is still not completed. In addition, to cope with this alarming situation, the government has banned large tourist boats from passing through Venice. However, in the future, with the impact of climate change causing sea levels to rise, sinking and high tides may become even more frequent in this city.
2 – Bangkok, Thailan
In second place is the city of Bangkok. Bangkok is the international and abbreviated name for Krung Thep Maha Nakhon, the official name of the current capital of Thailand. The city is located in central Thailand, right on the shore of the Gulf of Thailand, with a coastline of about 5 km. Although its area is only 1,569 km2, the population of Bangkok has reached 10.72 million people.
Due to its location in the lower Chao Phraya River basin, the southern region of the central plains of Thailand, Bangkok’s terrain is almost flat. The city’s average elevation is only about 1.5 m above sea level. As part of the Chao Phraya alluvial plain, the geological characteristics of Bangkok are characterized by a soft marine clay layer, known as Bangkok clay, which is on average 15 meters thick and covers a water-bearing layer. Due to the excessive exploitation of groundwater and the rapid urbanization, the capital of the land of the Golden Temple has been experiencing widespread subsidence. By the 1990s, subsidence had become a serious problem, reaching a rate of about 12 cm per year in 1981. Although management measures to minimize groundwater extraction have been implemented, the subsidence rate of Bangkok has continued to reach a rate of 1 to 3 cm per year.
Some areas of the city are currently located about 1m below sea level. Bangkok is entirely situated in a tropical climate zone with a hot and humid savanna climate. The average temperature here ranges from 22 to 35 degrees Celsius, rarely dropping below 18 degrees Celsius. The total annual rainfall here is about 1,658 mm, concentrated mainly from May to October, as this is the time when Bangkok is affected by the southwest monsoon, increasing humidity and causing prolonged rainfall. These factors, combined with the city’s low elevation and inadequate drainage infrastructure, often clogged by waste pollution and debris from the upstream of the Chao Phraya River, cause frequent flooding in Bangkok.
A notable example was in 2011, when most of the districts in the north, east, and west of the city were submerged in water, some for over 2 months. Some reports suggest that by 2030, most coastal areas such as Tha Kham, Samut Prakan, and Suvarnabhumi International Airport in Bangkok may be submerged in water. The National Reform Council of Thailand reported that the capital city is in an alarming situation for the next 15 years.
1 – Miami, Florida, USA
At the top of the list is the city of Miami, which is one of the largest cities in the state of Florida, USA. With an area of 93.2 square kilometers and a population of over 500,000, if you include the surrounding metropolitan area, the population of Miami reaches over 6 million people. The city of Miami and its suburbs are located in a wide, low-lying plain of the state of Florida. The average elevation of this city is only from 1.5 to 1.8 meters above sea level.
Due to the fact that the state of Florida is located in an area affected by both tropical and subtropical climates, it often faces natural disasters such as hurricanes and tropical storms. Along with Texas, Florida is the state most affected by hurricanes across the United States. It is estimated that several hurricanes make landfall in this state every year. According to natural disaster reports, Miami is one of the most hurricane-prone cities in the United States, with up to 80 days a year threatened by extreme weather events.
Due to the effects of climate change, sea levels are rising and hurricane frequency and intensity are also increasing. This is the main reason directly threatening the existence of the coastal city of Miami. In 2020, according to a report by Resources for the Future, unexpectedly, Miami topped the list of cities at high risk of being submerged by rising sea levels. The sea level in Miami is rising at the fastest rate in the world. In recent years, Miami has faced flooding, water pollution and caused significant damage to the city. In addition to coping with natural disasters due to climate change, Miami also needs to strengthen its infrastructure. By 2070, it is predicted that the sea level here will rise by about 60 cm, which will submerge the entire coastal area and cause severe damage to the city. It is highly likely that by the end of this century, the city of Miami will be completely submerged under the sea level.
These are the 8 cities in the world that are at high risk of being submerged by rising sea levels. According to you, which city will be the first victim of climate change? Leave your comments below this article. Goodbye and see you again in the next article.