Scientists have long warned that if rising sea levels as a result of global warming and melting ice caps continues, the habitats of both humans and animals could be lost to the ocean. New research, however, suggests coastal landscapes such as beaches may be more resilient than we give them credit for, provided they have space to move and migrate landwards. The research, published in the journal Nature Climate Change, instead warns that coastal defense structures such as seawalls may limit the ability of beaches to migrate inland and as such more focus should be placed on nature-based solutions to erosion.
The study comes from an international team of coastal scientists whose work refutes previous claims that half of the world's beaches could become extinct over the course of the 21st century. This damning prediction was published earlier this year in the same journal, but it is now being met by a rebuttal that concludes that the existing methodology and available data aren't sufficient to draw such wide-reaching conclusions.
The rebuttal comes from researchers in the UK, France, South Africa, Australia, New Zealand, and the USA who say that the previous study overlooked the potential for beaches to move in response to rising sea levels, but only where there’s space. Beaches that aren’t locked in by cliff faces or man-made structures are able to migrate landwards as shorelines retreat, retaining their overall shape and form further inland.
The prediction, if correct, is good news for beaches that have such space to pack up and shuffle landwards, but beaches surrounded by cliffs or engineering structures such as seawalls aren’t out of the woods yet. This new research states that these environments are likely to disappear as they are locked in and will first experience a “coastal squeeze” as they get narrower and narrower before disappearing entirely beneath the waves. The researchers suggest that structures such as seawalls that lock these beaches in should be removed, and that beach nourishment through nature-based solutions may be the only way to safeguard their future.
"New methods are needed for predicting impacts of sea-level rise on the coast,” said Professor of Coastal Studies at Ulster University and the new paper's lead author Andrew Cooper in a statement. “This will require better datasets of coastal morphology and improved understanding of the mechanisms of shoreline response in given settings. As sea level rises, shoreline retreat must, and will, happen but beaches will survive. The biggest threat to the continued existence of beaches is coastal defence structures that limit their ability to migrate."
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