A Quarter of the World's Beaches Are Disappearing

Around the world, about 30 percent of beaches, like this one in the Philippines, are sandy. Noel Celis/AFP/Getty Images

It's Friday, and maybe you're daydreaming about escaping to a beautiful sandy beach, soaking up some sun (after applying plentiful sunscreen) and listening to the waves. And you're in luck: Almost a third of coastlines around the world not covered in ice are beaches covered in sand or fine gravel.

But it's not all good news: about a quarter of those beaches are shrinking by a foot and a half every year, according to a new paper published in the journal Scientific Reports. Another quarter are growing and about half are staying more or less the same size.

The new study relies on satellite images dating back to 1984. Those images gave the researchers longer term and wider ranging data than previous studies had been able to access.

First, they had to identify sandy beaches in the first place—they found such beaches lined about two thirds of Africa's coasts and a quarter to a third of the coastlines of other continents.

Next, they looked at how those beaches were changing over the course of the three decades they had data for. In particular, they were looking out for beaches retreating by about 20 inches or more each year, which previous work has established as a red flag for disappearing beaches. They found that sort of erosion taking place at 24 percent of sandy beaches around the world.

Overall, beaches are shrinking in Australia and Africa. But North America and Europe and have some outstandingly disappearing beaches as well, like those at Freeport, Texas or Rockefeller reserve, Louisiana, each of which is retreating about 50 feet each year.

The research relied on almost 2 million historical images from the Landsat program, a series of government satellite missions that have taken measurements of Earth for almost half a century now. But scientists hoping to build on the new results may find themselves unable to do so in the future, since the government is considering putting Landsat data behind a paywall beginning as early as next year.