The impacts of climate change are becoming more and more visible today. Developments such as increasing incidents of forest fires, recent reclassification of New York City into a subtropical climatic zone and degrading coral reef across the planet, it is important to study and understand the long term impacts of the climate change and pre-plan for the events that are likely to occur in the near future.
An important occurrence of the near future (2100 CE) as a result of climate change would be coastal flooding and Seal Level Rise (SLR). According to a study by IPCC, a large population and assets will be globally affected as a consequence of SLR. The study has predicted that the global population potentially exposed to episodic coastal flooding will increase from 128-171 million to 176-287 million by 2100. It has also indicated that 0.5-0.7% of the world’s land area is at risk of episodic coastal flooding by 2100, which will impact 2.5 – 4.1% of the population.
In terms of the global assets, the study has said that the value of assets exposed to coastal flooding is projected to be between USD 6,000-9,000 billion or 12-20% of the global GDP. Globally, of the 68% area that is prone to coastal flooding, over 32% can be attributed to regional SLR. While normally, for most of the world, flooding incidents are typically associated with a 1 in a 100-year event, they could occur as frequently as 1 in 10 years, as a result of SLR.
The report expects oceans to rise between 10 and 30 inches by 2100 with temperatures warming 1.5 °C.
What would happen because of SLR?
Disappearance of many of the coastal cities: Globally, eight of the world’s 10 largest cities are near a coast. These cities are all threatened by coastal flooding and many are even threatened with sinking below the sea. Jakarta (Indonesia) is in fact known as the world’s fastest-sinking city, as it gains about 25 cm below the sea level every year. The Maldives, the island nation in the Indian Ocean Region is at the highest risk of submergence as it is barely 1 meter below the sea level.
Some of the noteworthy Indian cities that are at the risk of submerging because of SLR include Mumbai, Kolkata, Chennai and Surat.
Destruction of Coastal Biodiversity: SLR can cause destructive erosion, wetland flooding, aquifer and agricultural soil contamination with salt, and lost habitat for biodiversity. The SLR will also affect the coral reefs negatively as they may face difficulty in receiving sunlight. As a result of this, large scale coral bleaching may occur across the planet. This will heavily affect the coastal ecosystem.
Prevalence of dangerous storms: Higher sea levels and global warming is likely to result in more dangerous hurricanes and typhoons leading to loss of life and property.
Population Migration: Flooding in low-lying coastal areas will force people to migrate to higher grounds. This would cause displacement and dispossession and may lead to a refugee crisis worldwide. In addition to this, with limited land and resource availability, hyperinflation may occur across the world.
Adaptation Strategies across the Globe to the threat of SLR
Relocation: Many coastal cities have planned to adopt relocation as a mitigation strategy. For example, to protect its population from the potential submergence, the government of Maldives has allegedly acquired an alternate land at an undisclosed location for relocation. Kiribati Island in the Oceania region has planned to shift to Fiji Island in the same region. Indonesia is relocating its capital from Jakarta to Borneo.
Construction of the Sea wall: Indonesia’s government launched a coastal development project called a Giant Sea Wall or “Giant Garuda” in 2014 meant to protect the city from floods. These sea walls are being recommended for construction to all the cities at risk of coastal flooding across the world.
Building Enclosures: Researchers have proposed construction of Northern European Enclosure Dam (NEED) that will enclose all of the North Sea in order to protect 15 North European countries from SLR. The Persian Gulf, the Mediterranean Sea, the Baltic Sea, the Irish Sea, and the Red Sea were also identified as areas that could benefit from similar mega enclosures.
Architecture to redirect Flow of Water: Dutch City Rotterdam has built barriers, drainage, and innovative architectural features such as a “water square” with temporary ponds in order to steer the water flow and prevent the city from flooding and its resultant damage.
What needs to be done to check SLR?
While some of the above adaptation techniques are noteworthy, they are not enough to prevent the disasters that may occur if the sea level rises beyond control. In order to check the SLR, steps need to be taken that has long term impact. One of them is to ensure the reduction of future greenhouse gas emissions. The Paris Agreement has also provided with a clear vision for limiting global warming which is effective in checking the SLR.
To achieve such a vision, the governments, corporates, non-profits, NGOs and the citizens will have to take collective steps including:
1. Switching to clean energy.
2. Reducing the carbon footprint.
3. Installing mechanisms for carbon sequestration.
4. Increasing afforestation and reducing deforestation.
