The Rise of Sea Levels

While at the beginning of the 20th century, the increase was limited to one millimeter per year, by the end of the 20th century it had already risen to three millimeters. Studies suggest that this increase was the fastest in 3,000 years.

Why is global sea level rising?

This is easy to answer - the increase is one of the many severe consequences of climate change. The temperature of the oceans is increasingly rising, causing the seawater to expand. Furthermore, worldwide glaciers and the massive ice masses in Greenland and Antarctica are melting. Greenland is particularly heavily affected by climate change and has already warmed significantly more than any other region on Earth. Research suggests that since 2002, an incredible 4,700 tons of ice have been lost. Nowadays, it can even rain where Greenland's highest weather station is located - at 3,216 meters above sea level. For instance, this was the case in 2021, where 12 billion tons of ice melted in a single day. Research findings indicate that even if global CO2 emissions could be stopped now, Greenland's ice sheet would still lose 110 trillion tons of ice over the next few decades. This would result in a global sea level rise of at least 27 centimeters.

Bleak Outlook for Some Regions

The problem is global. In addition to cities like Shanghai or entire regions in Asia, Europe is also not spared: cities like Amsterdam or Venice, but also Bremen and Hamburg, are affected by the consequences of the rise of the global sea level. In the coastal regions, it is also often the case that the cities and their foundations sink. This phenomenon is also due to the influence of humans - specifically, when groundwater is massively pumped, it leads to land subsidence. This is sometimes up to ten times faster than the rise in sea levels. So, two factors that make coastal cities disappear meet here - Jakarta is at the forefront here. The capital of Indonesia is sinking more strongly than any other city in the world, by an average of three centimeters per year, 40 percent of the city is already below sea level. In some areas of the city, the ground is sinking by already 25 centimeters per year due to concurrent rise in sea levels due to global warming. Jakarta is so heavily affected by the factors caused by humans that the government decided in 2019 to abandon Jakarta and build a new capital on the island of Borneo.

Is There Salvation for the Maldives, Venice, Miami, Shanghai?

Even if we manage to keep global warming well below two degrees, it will not be enough to permanently save low-lying islands and cities. It would contribute to slowing down the rise in sea levels, but not stop it, as the sea responds to warming in a time-delayed manner. Only measures can be taken to combat the rising waters - this is being attempted with the construction of sea dikes, walls, better drainage and canal systems, but also the elevation of roads or the relocation of entire villages and small towns.

New Ideas are Needed

With such ideas, the Netherlands can demonstrate what can be done, essentially born out of necessity because large portions of the country are below sea level. Alongside the construction of dams and barricades, the Dutch are resorting to floating houses and apartments, even whole settlements. These are connected to the mainland via bridges. These floating communities are not utopian future concepts, but are already in use - the Maldives are even planning to build a floating city by 2027. Another measure to prevent flooding and absorb rainwater involves creating sponge cities. In these cities, it is intended that rainwater will be absorbed through green spaces and permeable paving stones and reused. This leads to an increase in the cities' water reserves and protects against sinking.

The Future

All measures such as curbing global warming, floating cities, or shoreline dams will not change the fact that residents of some affected regions will have to leave their sinking land. This applies equally to poorer regions in Asia as well as wealthier regions like the state of California. In Californian coastal towns, there are already houses separated from the sea by only a narrow strip of sand. Due to our human-made climate change, we have laid the foundations that force millions of people to leave their homes and become climate refugees.