Climate change poses many serious challenges; among those, the rise in the sea level is undoubtedly the most alarming. Global sea levels have risen faster than since the beginning of the 20th Century, and it has become much worse in recent years. The sea has risen 21 centimetres since the records began in 1880; half of this has occurred in the last 30 years. By the end of this century, the global sea level will likely rise at least 30 centimetres above the 2000 level, even if countries could keep global warming to a 1.5-degree Celcius limit. The sea level was almost constant for 3000 years before the 19th Century.
Two primary causes of the unprecedented sea level rise are melt water from glaciers and ice sheets and seawater expanding due to increased global temperature. Intense groundwater pumping in many parts of the world is also the third but relatively minor factor for this rise. Ice loss in Antarctica has increased four times in the last 30 years, and the melting of the ice sheet in Greenland has increased seven-fold during this period. The Arctic is melting dangerously, but its contribution to sea level rise is insignificant as sea ice turns to seawater.
The accumulation of greenhouse gases in the atmosphere has warmed the planet, and 90 per cent of the trapped heat is absorbed by its five oceans. Global warming is resulting in the thermal expansion of seawater as, like any other material, the seawater is also expanding due to increased temperature.
How rising sea level threatens populations
Approximately one-third to one-half of global sea level rise occurs due to warming water. As global temperature rises, the sea level will inevitably rise further. Nearly 40 per cent of the world’s population lives within 100 kilometres of a seashore, and there is no doubt that the rising sea threatens the place and source of survival of a large population.
On February 14, the UN Security Council held a ministerial-level open debate on sea level rise and its implications for international peace and security. The UN Secretary-General described it as a threat multiplier and said its impact is “already creating new sources and instability and conflict.” Despite reservations from countries like Brazil, China, India, and Russia about its mandate to discuss and decide issues concerning climate change, the Security Council has warned the world about the sea-level rise since 2011.
Much of the Arab world is already water scarce, and the sea level rise will increase its difficulties further by bringing increased salinity to their groundwater and agricultural land.
The unprecedented rise of the sea level poses a few severe threats to people and the ecosystem along the coast. The rising sea has increased the intensity of storm surges and flooding, contaminating soil and groundwater. Nearly ten per cent of the global population lives in low-lying coastal areas less than 5 metres above the high tide line. Thus, it is feared that at least 100 million people will be forced to migrate due to the rising sea by the end of this century. The last year’s report from Visual Capitalist warns that nearly 360 million people will face the risk of annual flooding by 2100.
The same report from the Visual Capitalist says Egypt in Africa, China, Bangladesh, India, Vietnam, Indonesia, Thailand, the Philippines, and Japan in Asia, the Netherlands in Europe, the US in North America, and Brazil in South America will be most severely affected by rising sea levels.
Much of the Arab world is already water scarce, and the sea level rise will increase its difficulties further by bringing increased salinity to their groundwater and agricultural land. The agricultural production in the Nile Delta will be severely affected, creating food insecurity for Egypt. The IPCC has warned that rising water levels will partly submerge several coastal cities in the Middle East.
Countries in danger of disappearing
The most vulnerable to sea level rise are small island developing countries. Several of them in the Pacific and Indian Ocean are concerned that the storm surges, high floods, and saltwater intrusion are already harming their health, agriculture, and economy. Even their physical survival as a country is in danger due to the increasing submergence of islands under the rising sea.
Five islands of the Solomon Islands have already disappeared into the ocean. As small and low-lying islands disappear, the people there are forced to migrate to bigger and higher islands.
The people in the Carteret Islands of Papua New Guinea were forced to relocate to Bougainville Island. The South Asian Island nation Maldives, with more than 1000 islands, is vulnerable because 80 per cent of its land area is less than one metre above sea level. It has built a new island, Hulhumalé, next to its capital with higher height, and for this island country to survive, it must raise the heights of its islands or build new ones. This will not be easy for Maldives or other small island countries.
The immediate fear of the small island countries, particularly in the Pacific and Indian Ocean, is that shrinking their remote islands will reduce their exclusive economic zones (EEZs), which stretch 200 nautical miles offshore. There is an attempt to claim permanent EEZ in the Pacific, but that lacks a legal mandate under the 1982 UN Convention of the Law of the Sea (UNCLOS).
Ten Pacific Island countries have a land area about the size of Florida but their total EEZs bigger than the moon’s surface. If the island is submerged or becomes uninhabitable, it does not qualify for an EEZ under the UNCLOS. Renegotiation of UNCLOS will not be that easy. That brings enormous economic uncertainty to the small island countries and carries profound geopolitical implications and possibilities of fueling several territorial conflicts.
Sea level rise is no longer a hypothetical apprehension. It has already become a harsh reality, and the world needs to wake up to its multi-faceted risks and challenges.
— Ashok Swain is a professor of peace and conflict research at Uppsala University, Sweden.