Sea-level rise and coastal shifts could wipe out nearly half of Earth’s sandy seashores by the end of the century.

Storm surges, waves and rising seas could help to erase almost half of all sandy beaches by 2100.

Michalis Vousdoukas at the European Commission’s Joint Research Centre in Ispra, Italy, and his colleagues analysed the shift of sandy shorelines around the globe between 1984 and 2015. The team then estimated future shoreline changes driven by geological factors, such as sand loss, and human activities that affect sediment supply. The researchers also modelled the effects of rising water levels and growing storm-surge height — both caused by increasing sea levels — on shorelines.

By the end of the century, many of the world’s coast lines will have retreated by more than 100 metres from their positions in 2010, even if atmospheric levels of greenhouse gases rise only moderately. The Democratic Republic of the Congo, the Gambia, Suriname and Pakistan are among the places where more than 60% of beaches would be affected. Australia could lose the greatest amount of sandy coastline: at least 11,426 kilometres.

Coastal planners could stave off much of the erosion by carefully managing beaches.