Explained: Why India Is Among The Countries Facing Highest Threat Of Sea-Level Rise Globally
According to the World Meteorological Organization’s (WMO) “Global Sea-level Rise and Implications” report, India, China, Bangladesh, and the Netherlands are at the greatest risk of experiencing rising sea levels worldwide.
The increase in sea level poses a threat to numerous major cities on all continents, including Shanghai, Dhaka, Bangkok, Jakarta, Mumbai, Maputo, Lagos, Cairo, London, Copenhagen, New York, Los Angeles, Buenos Aires, and Santiago.
What did the report say?
From 2013 to 2022, there was an annual increase in global mean sea level of 4.5 mm, with human influence being the primary factor behind this trend since at least 1971.
Between 1901 and 2018, there was an overall increase of 0.20m in global mean sea level, with a yearly increase of 1.3 mm between 1901 and 1971, 1.9 mm between 1971 and 2006, and 3.7 mm between 2006 and 2018.
Even if global warming is limited to 1.5 degrees Celsius above pre-industrial levels, there will still be a substantial rise in sea levels. However, each increment of temperature increase matters, as a 2-degree rise in temperature could double the sea level rise, and further temperature increases could lead to exponential sea level increases.
During the period of 1971-2018, 50% of sea level rise was due to thermal expansion, while 22% was due to ice loss from glaciers, 20% was due to ice-sheet loss, and 8% was due to changes in land-water storage.
The rate of ice-sheet loss increased by four times between 1992-1999 and 2010-2019. Ice sheet and glacier mass loss were the primary contributors to global mean sea level rise during 2006-2018.
How will it impact?
If the temperature continues to rise by 2-3 degrees Celsius, the Greenland and West Antarctic ice sheets will face almost complete and irreversible loss over multiple millennia, resulting in a potential multimeter increase in sea-level rise.
The rise in sea levels will have a cascading effect, leading to the loss of coastal ecosystems and ecosystem services, as well as groundwater salinisation, flooding, and damage to coastal infrastructure.
These will all have a domino effect on the risks to livelihoods, settlements, health, well-being, food, displacement, water security, and cultural values, both in the short term and long term.
It is crucial to tackle the climate crisis and expand our comprehension of the underlying reasons for insecurity. It is essential to actively endorse grassroots initiatives for enhancing resilience against climate change and enhancing Early Warning Systems.
Indian Ocean is warming up at the fastest rate
The Ministry of Earth Sciences reports that the sea level along the Indian coast has been rising at an average rate of about 1.7 mm/year over the last century (1900-2000).
A sea level rise of 3 cm could result in the sea intruding about 17 meters inland, and with future rates of 5 cm/decade, this could increase to 300 meters of land lost to the sea in a century.
According to a report by Indian Express, India is particularly vulnerable to the compounding impacts of sea level rise. In the Indian Ocean, half of the sea level rise is due to the warming of the ocean, which is causing the volume of water to expand rapidly. At the same time, the contribution from glacier melt is not as significant.
The Indian Ocean is warming up at the fastest rate in terms of surface warming. This has resulted in compound extreme events along the Indian coastline, with cyclones intensifying rapidly due to the increased moisture and heat from ocean warming.
Storm surges are exacerbating the sea level rise, leading to increased flooding. Cyclones are also bringing more rain than before. Over time, the deltas of major rivers such as the Indus, Ganga, and Brahmaputra may become uninhabitable due to the combined effects of rising sea levels and saltwater intrusion.