About half of the world’s population lives within the coastal zone, but how long will it last? According to core samples, tide gauge readings, and more recently, satellite measurements, the Global Mean Sea Level has risen by 10 to 20 centimetres (4 to 8 inches). Even a small increase in sea level can have devastating effects on coastal habitats, by way of damaging erosion, wetland flooding, agricultural soil contamination, and losses of habitat for fish, birds, and plants.

The vast amount of carbon dioxide that has been released in the air by the burning of fossil fuels has continuously increased the earth’s surface temperature. The gasses are trapped in the atmosphere and the ocean then absorbs about 80% of the additional heat. This inevitably leads to a rise in sea level, which is linked to three main causes.

Thermal expansion is one of the reasons, as when water heats up, it expands. Oceans simply occupying more space due to the rise in temperature has had a major contribution to rising sea levels for the past century. Another great factor is the melting of glaciers and the polar ice caps. Even though the ice caps naturally melt slightly during the summer, it has dramatically worsened due to the higher temperature caused by global warming. During the winter, the ice caps generally balance out the melting, but the rising temperature has also had an effect on snowfall. This has led to snow appearing much later and spring starting earlier. A greater amount of glaciers melt due to the imbalance, which causes the sea level to constantly increase. Furthermore, ice loss doesn’t only occur due to glaciers and polar ice caps from the north, but Greenland and West Antarctica have also experienced dramatic changes to their landscape. Higher sea temperatures are causing massive amounts of ice that extend out from Antarctica to melt from below, which inevitably weakens it until it breaks off.

Millions of people live in areas that are increasingly more vulnerable to floods and therefore could even be forced to abandon their homes if the situation isn’t resolved. Researchers believe that if the sea level constantly rises, it can reach up to 98 cm, which could flood many cities along the coast and possibly submerge low lying areas completely.