One of the effects of climate change is the rise of sea level. Based on National Geographic, the change in sea levels is linked to three primary factors: Therma expansion, when water heats up, it expands; melting glaciers, which, with higher temperatures caused by global warming, have led to more melting of mountain glaciers than average; and the loss of ice sheets that cover Greenland and Antarctica due to melting.
According to NASA, global sea levels are rising because of human-caused global warming. Currently, the sea level is rising 3.4 mm/year. By 2100, it is estimated by NOAA Global Mean Sea level a rise an of 2.5 meters. This may not seem much for some people, but it does have a great impact on us. With the rising sea level, some of the impacts are physical changes, such as increasing the frequency and strength of coastal flooding and storms. There are not just physical changes, but also socio-economic and infrastructure changes of coastal cities. Roughly, more than a billion people worldwide live in coastal regions and these people will have to deal firsthand with those physical and socio-economic changes.
Unfortunately, many of the large cities (New York, Tokyo, Rio de Janeiro, Shanghai, Calcutta) worldwide are located on the coast and particularly vulnerable to flooding. Nuisance flooding (or flash flood) are more recurrent because of sea level rise. Although the impact could be considered minor (depends on the region), water may overtop some seawalls and it can inundate roads, disrupt transportation, cause damage to infrastructure.
Some of the coastal cities are highly aware of their vulnerability. Therefore, they have been implementing defense mechanisms to mitigate the risks by adapting buildings and settlements, creating flood barriers or sea walls. Take for instance all the Dutch defense barriers against storm surges to protect Netherlands from flooding. Their barriers are very efficient. They have been able to moderate the sea level and prevent their land from any major flooding. Besides ditches, they started building defense mechanisms against floods in the late 20th century since the Netherlands has a long flood history even before climate change became a concern. One of their barriers, the Maeslantkering, costs about 660 million euros in total.
Moreover, not all countries have storm surge barriers like the Netherlands. These defense mechanisms are costly to build and maintain. I’m wondering about how countries will handle paying for defense mechanisms since there are no guarantees for the long term for seawalls, dikes and dams as long as we keep contributing to climate change. That scenario can lead to a having all citizens of coastal cities relocate to some other safe place and consequently have a great negative economic impact for both citizens and government. That can mean a higher rate of unemployment, homeless and food insecurities which brings us to the socioeconomic changes mentioned before.
As we saw previously, one of the consequences of sea levels rising is frequent flash flooding causing a chain of physical and socio-economic impacts. There is no doubt fighting against these impacts to limit the harm caused to us is challenging. I personally don’t have any specific suggestions on how we are supposed to fight this situation, but Elliott Negin, a senior writer, does. In his words, “We must harness policy and market solutions that work for people, ecosystems, coastal heritage, and the economy. This means investing in updated flood risk maps that reflect the latest science, reforming the National Flood Insurance Program so that it helps promote coastal resilience instead of subsidizing risky choices and includes affordability provisions for low- and fixed-income folks” plus other suggestions he wrote on his blog. You can read more about it on the link below, along with other weblinks used as a reference for this essay.