Reposted by NoTricksZone
By Kenneth Richard on December 21, 2020
Despite a rise in sea levels, a 2019 global analysis (Duvat, 2019) found that 89% of the island’s 709 coastlines were either stable or increasing in size over the past few decades. A new study only on the Maldives (Duvat, 2020) shows rapid (> 3 to> 50%) coastal growth on 110 of 186 Maldives islands from 2005 to 2016. Only 5 islands – 2.7% – have changed during this period actually scaled down.
Last year Dr. Virginie Duvat published a global assessment how the world’s islands and atolls hold up against the ongoing challenge of sea level rise since satellite surveillance began in the 1980s.
Fortunately, she found “no widespread signs of physical destabilization in the face of rising sea levels”. In fact) a) none of the 30 analyzed atolls lost land area, b) 88.6% of the 709 examined islands were either stable or enlarged in area, c) no island larger than 10 hectares (ha) decreased in size and d) only 4 of 334 islands (1.2%) larger than 5 hectares had lost in size.
This year, Dr. Duvat is focused on the Maldives, a region believed to be one of the most severely affected by sea level rise disturbances. About 80% of the islands are less than 1 meter above sea level.
Given that the Maldives’ population (> 400,000) has doubled every 25 years since the 1960s and nearly 1.3 million tourists visit many of the 188 inhabited islands each year, the Maldives Islands are in for the ongoing impact assessment of modern sea level change is crucial.
And luckily, as in the rest of the world, the Maldives is doing pretty well.
Due to human ingenuity – technical feats like island rearing, artificial expansion of island areas and “armoring” the coastline – most of the Maldives have actually grown in size in the last few decades.
Since 2005, 110 (59.1%) of the 186 islands examined have grown by ≥3%. Of these 110 expanding islands, 57 grew ≥ 10% and 19 grew ≥ 50% (Duvat, 2020). That too is only in the last decade.
Of the islands that did not increase in size, 38.2% (71 islands) were classified as stable (defined as neither growing nor shrinking by more than 3%). This leaves only 5 of 186 islands (2.7%) whose size has decreased since the 1980s.
In other words, 97.3% of the Maldivian islands have either been stable or have increased in size since 2005.
Another new study (Kench et al., 2020) helpfully presents the long-term context of the Holocene sea level for the Maldives. We find that islands that are now above sea level were submerged under sea water 3,000 years ago.
About 4,000 to 2,000 years ago, the sea level in the Maldives was about 0.5 m above today’s level. In the past thousand years, natural vibrations of ~ 0.8 m have occurred in a few centuries, including collapses during the Late Antique Little Ice Age (~ 1600 years ago) and the Little Ice Age (~ 400 years ago).
Modern changes in sea level do not appear to be outside the range of natural variability.
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