Rising Sea Levels: A Looming Threat to Coastal Cities and Beyond

Can you imagine being able to jump directly into the sea from the window of your room?

Under normal circumstances, this assumption may be difficult to achieve, but it is not as far-fetched as you might think. According to scientists' predictions, the sea level in 570 coastal cities worldwide will rise by 0.5 meters by 2050. Some low-lying major cities, such as Singapore and Tokyo, may face the threat of being submerged, which is undoubtedly a disaster for many people in those areas. The rising sea levels are inevitable, so what kind of harm will this slow-onset natural disaster bring to humanity?

Firstly, rising sea levels will submerge coastal lowlands and exacerbate coastal erosion. The rising sea levels cause increased ocean dynamics, submerging low-lying areas, and intensifying coastal erosion disasters. Once coastal erosion occurs, it will bring disasters and economic losses to coastal areas, such as the erosion of large areas of land. Taking the coast of northern Jiangsu Province as an example, the coastline of the abandoned Yellow River Delta has retreated by about 30 kilometers since 1855, resulting in a loss of 1600 square kilometers of land.

Secondly, rising sea levels worsen saltwater intrusion and soil salinization. As the sea level rises, the salinity of soil and freshwater resources in coastal areas increases, and saltwater intrusion is affecting groundwater supplies and soil resources worldwide. At the same time, during the dry season of rivers flowing into the sea, abnormally high sea levels can cause severe saltwater intrusion, intensifying soil and freshwater salinization. In Egypt, as a result of climate warming and rising sea levels, more and more seawater is backflowing into the fertile agricultural area of the Nile Delta, affecting the food supply of 80 million Egyptians.

Lastly, rising sea levels increase the risk of flooding. Due to the relative rise in sea level, the drainage capacity of low-lying areas decreases, causing a large amount of floodwater to accumulate in the hinterland during the flood season, severely affecting the flood discharge in estuarine areas and increasing the threat of flooding. In the Tianjin area, with an average elevation of only 2 meters, when the water level of the river rises to 4 meters during the flood season, the Hedong District of Tianjin City will be flooded. If sea levels continue to rise, the drainage flow into the sea in these areas will decrease, and the duration of flooding will increase, making the flood risk even more severe.

In conclusion, the long-term cumulative effects of rising sea levels exacerbate marine disasters. In the past, the slow process of rising sea levels was easily overlooked, but now people living in coastal areas are increasingly feeling the impact of rising sea levels.