How much will sea levels rise due to the climate crisis?

Rising sea levels due to the climate crisis

What does a rise in sea level mean?

A rise in sea level means that the surface of the seawater increases in relation to the height of the adjacent land. Seawater is encroaching on our coasts and the body of water takes up more and more land. When the sea level reaches a certain height, flooding can occur.

Why is global warming causing the sea level to rise?

The rising sea levels are triggered by the climate crisis. Fundamentally, there are three driving forces behind sea level rise.

• Expansion of seawater due to higher water temperatures Water is densest at 4 degrees Celsius, which means it takes up the least space at this temperature. When you heat the water, it expands. Water with a temperature of 20 degrees takes up more space than water that is only 10 degrees. So the warmer the water in the oceans, the more space it needs.
• Melting glaciers and ice sheets Rising temperatures also lead to the melting of glaciers and ice sheets in the polar regions and mountains. This meltwater flows into the oceans and contributes to rising sea levels.
• Melting of the ice sheets in Greenland and Antarctica The ice sheets in Greenland and Antarctica contain enormous amounts of frozen water. Once melted, this water also enters the oceans and contributes to sea level rise.

Rising sea levels are a lie?

There is a rumour going around in some circles that there is no rise in sea levels at all. But the fact is that the rising sea levels have been scientifically proven by countless studies and tests. Data from sediment cores, tide gauges and satellites confirm that sea levels are rising worldwide. Unfortunately, sea level rise has accelerated in the last century.

Here is an article that addresses the myth that sea levels are not rising.

Current state of research on sea level rise

How much has the sea level already risen?

In the 20th century, sea levels have already risen by 20 centimetres. According to the IPCC, sea levels are currently rising by 3.7 millimetres per year. That is more than twice as fast as in the 20th century. At that time, the annual rise in sea level was 1.5 millimetres per year. From 1993 to 2022 alone, the sea rose by more than 10 centimetres. Where we go from here depends on whether we succeed in slowing down man-made global warming.

If you click on the link behind the following image, you will be taken to a NASA animation on sea level rise.

How much will sea levels rise?

According to the [IPCC report of 2022]/en/post/ipcc2022-part1), the average global sea level will rise by about two to three metres over the next 2000 years if global warming is limited to 1.5°C. It will rise by two to six metres if warming is limited to 2°C and by around 19 to 22 metres if the planet warms by 5°C. The latter would mean that millions of people would be at risk, coastal cities could no longer exist and elaborate protection systems would have to be built.

If the entire Greenland ice sheet melts, global sea levels would rise by over seven metres. If we add the meltwater from the Antarctic ice sheet, the global sea level would increase by an astonishing 58 metres. Even though this scenario is unlikely, in some places just a few centimetres are enough to provoke devastating effects.

Who is affected by rising sea levels?

Sea level rise: What are the consequences for people?

The rising sea level mainly affects people living in coastal areas. The consequences of sea level rise are far-reaching. Here are the most important ones:

• Floods and storm surges Rising sea levels increase the risk of flooding and storm surges in coastal areas. This puts people at risk, damages homes and cripples infrastructure.
• Loss of land and coastal erosion As sea levels rise, coastal areas are eroded and land is lost. Houses and settlements have to be abandoned or relocated. It will become impossible to farm the land and there will be much less space available for people.
• Threat to sources of drinking water In some coastal areas, seawater is encroaching on groundwater resources, endangering drinking water supplies. When salt water comes in contact with agricultural land, the soil can become infertile.
• Health risks Floods can lead to water contamination, allowing bacteria to spread. Mosquitoes multiply, transmitting diseases such as dengue fever or malaria.

Depending on the geographical location, sea level rise has different effects. Overall, however, it is clear that high sea levels pose numerous challenges for both humans and animals.

Sea level rise: Which places will be affected?

Rising sea levels will primarily affect people in coastal regions. This includes the inhabitants of major cities like New York, Miami, Mumbai or Shanghai. The German coast is 2,400 kilometres long. Here, too, you can find cities such as Bremerhaven, Cuxhaven, Flensburg, Friedrichstadt, Kiel or Lübeck.

Island states are also affected by rising sea levels. The Maldives, Tuvalu, Kiribati and the Marshall Islands are particularly at risk with sea level rise causing flooding and erosion. Around 700 million people worldwide live in low-lying coastal areas that could be affected by rising sea levels.

Not only people are affected by sea level rise. Entire ecosystems such as mangrove forests, wetlands and coral reefs are also being damaged. Many plant and animal species are seriously threatened by the rising sea level.

What about rising sea levels in Germany?

The dangers of sea level rise due to climate change also affect Germany. The water levels of the North Sea and Baltic Sea have been rising for decades. Depending on the coast, sea level rise varies. This is due to different wind systems and currents. Here you can find a comparison of the sea levels in well-known German coastal cities over the last 100 years.

How can we prevent sea level rise?

Sea level rise is directly linked to the man-made greenhouse effect and global warming. To slow down this process, we need to reduce our CO₂ emissions.

With ForTomorrow, you can buy away emission rights from industry and cancel them, thereby reducing CO₂ emissions in Europe. This is how we slow down the greenhouse effect, global warming and sea level rise.