Danger of faster sea level rise

American south is witnessing an alarming rise in sea level affecting coastal communities across eight US states, says a Washington Post analysis reported last month (April 29). The tide gauges of the water level monitoring stations at more than eight points from Texas to North Carolina found that sea levels were 6 inches higher than they were about a decade and a half ago (in 2010, to be specific). And that was equivalent to the amount of sea level rise the area under study saw in the past five decades, the report further said. Scientists, according to the report, said that the Gulf of Mexico had experienced twice the global average rate of sea level rise since 2010 as revealed from the analysis of satellite data. Scientists are learnt to have been working to decipher what lay behind such accelerated rise of the sea level. But it is not the US south coast alone that has been witnessing the phenomenon of faster sea level rise.
'The World Meteorological Organisation (WMO)'s State of the Global Climate in 2021' report released in May 2022 said, globally, the rate of sea-level rise was 4.5 millimetres per year between 2013 and 2021. That was twice the rate between 1993 and 2002. And the explanation was the obvious one-the accelerated loss of ice from the Arctic and Antarctic ice sheets due to global warming. But the sea level rose during that time despite the fact that La Nina was prevailing at that time (from the beginning to the end of 2021). Notably, during the La Nina years, seas stay at a less than mean level. Conversely, when it is El Nino, the seas rise to more than mean level.
Now, though La Nina and El Nino are weather patterns that happen in the Pacific Ocean, they can impact global weather patterns substantially. El Nino is warming of the ocean surface in the eastern and central Pacific. La Nina, on the other hand, is cooling of the same regions of the Pacific Ocean. Interestingly, these two weather phenomena can impact the patterns of precipitation, wind, temperature, etc. giving rise to extreme weather events like drought, downpours and floods, to name but a few.
The reported sea level rise on a global scale, however, is not taking place uniformly. In the Indian Ocean region sea level rise is taking place at the fastest rate, particularly in its south-eastern part. In fact, in that part of the Indian Ocean, the sea level was rising faster than the global average by 2.5 mm per year.
A Department of Environment (DoE)-conducted study titled, 'Estimation of Sea Level Rise (SLR) in Bangladesh using Satellite Altimetry Data', has found that like all other parts of the world's oceans, the coastal areas of Bangladesh are also experiencing faster sea-level rise, which is more than global average of 3.42 mm per year.
Bangladesh is already among the countries most at risk from sea level rise. Noting that global sea levels have risen faster since 1900, the UN Secretary General Antonio Guterres in his speech in February 2023 at the first ever Security Council meeting on the threat that sea-level rise poses to international peace and security, warned that countries like Bangladesh, China, India and the Netherlands were at serious risk.
The findings of the DoE-conducted study are a stark reminder of what is in store for the population of the country's coastal districts in the not-too-distant future. The study found that 12 coastal districts are at great risk from problems related to sea level rise including waterlogging, high salinity, high temperatures, excessive rainfalls and, of course, massive crop damage.
And as a result of the increased frequency of sea-borne calamities like storm surge and coastal inundation, more than a million people could be displaced. The districts most vulnerable to inundation include Jhalakathi, Pirojpur and Barishal. Comprehensive flood protection measures will be required to protect them.

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