Sand ecosystems occupy more than a third of all coasts and their value is not only tourist, but also environmental. With current climate trends, 50% of the world's beaches will most likely disappear underwater before the end of the century.
Sandy beaches are not just paradisiacal places in remote destinations. In addition to their important socio-economic and tourist value for many countries, these ecosystems, which occupy 30% of the world's coastline and are home to 44% of the world's population, represent much more in our surroundings.
“The beaches have an ecological value since they are home to several species that cannot live in other environments. Being on the front line they also provide protection against floods, marine storms and cyclones”, Michalis Vousdoukas, from the Joint Research Center of the European Commission in Ispra (Italy) tells SINC.
Despite their ecological importance, many beaches, which are facing constant weather and anthropogenic changes, are already eroding, a situation that will be exacerbated by climate change and rising sea levels. To predict future trends, Vousdoukas and his team analyzed satellite images showing the change of the coastline from 1984 to 2015.
The results, published in the journalNature Climate Change, reveal that the coastal recession due to rising sea levels and current climate trends could cause the near extinction of half the world's sandy beaches by the year 2100. Erosion also appears to be intensifying as Emissions of greenhouse gases.
“Almost half of the world's sandy beaches will be lost if we do not reduce greenhouse gas emissions. Mitigation would prevent 22% of the withdrawal from the coast by 2050 and 40% by the end of the century”, Adds the expert, who has had the collaboration of the University of Cádiz and other centers in Holland and Portugal.
Australia, the country that will lose the most beaches
Thanks to the compilation of 30 years of satellite images, the scientists were able to determine the change that the coast will undergo in the coming decades in two different climate emergency scenarios: due to geological and anthropogenic factors and due to sea level rise.
The researchers concluded that these ecosystems are at risk of severe erosion. Until the end of the century, “beaches will continue to erode and some will disappear”Warns Vousdoukas. In West and East Asia and the small island countries of the Caribbean, a long-term retreat from the coast of up to 300 meters is expected.
But the risk of erosion will be particularly high in countries where both climate scenarios occur, such as the Democratic Republic of the Congo, Gambia, Jersey, Suriname, Comoros, Palau, Benin, Guinea-Bissau, Mayotte (France), Iraq , Pakistan, Guinea and El Salvador.
All of them could lose up to 80% of their sandy coastline, which will harm their fragile economies that depend on tourism, and where sandy beaches are the main attraction.
When the researchers analyzed the total length of beach that could be lost, Australia was the most affected country with 12,324 km of coastline at risk (in the best case scenario), which is equivalent to 40% of the entire sandy coastline of the country. They would be followed by Canada (which will lose 9,577 km of beaches), Chile (5,471 km), Mexico (4,119 km), China (4,084 km), USA (3,908 km), Argentina (3,668 km) and Iran (3,654 km).
As a significant proportion of threatened sandy beaches are in densely populated areas, the research team suggests designing and implementing effective adaptation measures.
By Adeline Marcos
Michalis Vousdoukas et al. "Sandy coastlines under threat of erosion"Nature Climate Change March 2, 2020