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Scary! Low lying tropical islands could be uninhabitable within 30 years

Scary! Low lying tropical islands could be uninhabitable within 30 years

Low lying tropical islands could be uninhabitable within 30 years due to rising sea levels and wave-driven flooding, new research suggests. Islands including paradise holiday destinations like the Seychelles and Maldives (pictured) could be affected as soon as 2030, they say.

    • Experts studied Roi-Namur Island in the Marshall Islands from 2013 to 2015
    • The primary source of drinking water for atolls is rain that soaks into the ground
    • Rising sea levels are predicted to result in seawater contaminating this source
    • This is predicted to be an annual occurrence by the middle of the 21st Century
    • Human inhabitatance of atoll islands could become impossible by 2030 to 2060

Low lying tropical islands could be uninhabitable within 30 years due to rising sea levels and wave driven flooding, new research suggests. Experts warn that freshwater reserves on atolls in the Pacific and Indian oceans will be so damaged by climate change that many will no longer support humans. Scientists predict that a tipping point will be reached in the middle of this century when groundwater that’s suitable for drinking will disappear completely. Islands including paradise holiday destinations like the Seychelles and Maldives could be affected as soon as 2030, they say.

Researchers from the US Geological Survey (USGS) and the University of Hawaii at Mānoa focused on Roi-Namur Island on Kwajalein Atoll in the Republic of the Marshall Islands for their site study, which took place from November 2013 to May 2015.  The primary source of freshwater for populated atoll islands is rain that soaks into the ground and remains there as a layer of fresh groundwater that floats on top of denser saltwater. However, rising sea levels are predicted to result in storm waters and other waves that wash up and over the low lying islands, known as overwash. This process makes the freshwater on atolls unsuitable for human consumption.

Experts used a variety of climate change scenarios to project the impact of sea level rise and wave driven flooding on the area. Scientists predict that, based on current global greenhouse gas emission rates, overwash will be an annual occurrence in most atoll islands by the mid-21st Century. The resulting loss of drinkable groundwater will make human habitation difficult in most locations beginning in the 2030s to 2060s, they say. This will likely require the relocation of island inhabitants or significant financial investment in new infrastructure, researchers warn.

Researchers focused on Roi-Namur Island on Kwajalein Atoll in the Republic of the Marshall Islands (pictured) for their site study, which took place from November 2013 to May 2015 & Experts warn that freshwater reserves on atolls in the Pacific and Indian oceans, like those of the Marshall Islands (pictured) will be so damaged by climate change that many will no longer support humans

tudy co-author Dr Stephen Gingerich, a USGS hydrologist, said: ‘The overwash events generally result in salty ocean water seeping into the ground and contaminating the freshwater aquifer. ‘Rainfall later in the year is not enough to flush out the saltwater and refresh the island’s water supply before the next year’s storms arrive repeating the overwash events.’ The Republic of the Marshall Islands has more than 1,100 low-lying islands on 29 atolls, and is home to hundreds of thousands of people. Sea levels are rising, with the highest rates in the tropics, where thousands of low-lying coral atoll islands are located. The team said their approach can serve as a proxy for atolls around the world, most of which have a similar landscape and structure – including, on average, even lower land elevations.

Researchers said that the new findings have relevance not only to the Marshall Islands, but also to those in the Caroline, Cook, Gilbert, Line, Society and Spratly Islands as well as the Maldives, Seychelles, and Northwestern Hawaiian Islands. Previous studies on the resilience of these islands to sea level rise projected they will experience minimal inundation impacts until at least the end of the 21st century. But the previous studies didn’t take into account the additional hazard of wave-driven overwash nor its impact on freshwater availability. Study lead author Dr Curt Storlazzi, of the USGS, added: ‘The tipping point when potable groundwater on the majority of atoll islands will be unavailable is projected to be reached no later than the middle of the 21st Century. ‘Such information is key to assess multiple hazards and prioritise efforts to reduce risk and increase the resiliency of atoll islands’ communities around the globe.’

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