学进去

Climate change leads to a threat to the world’s sandy beaches, and as many as half of them could disappear by 2100, a new study has found. Even by 2050 some coastlines could be unrecognizable from what we see today, with 10% to 12% facing severe erosion (侵蚀).

Using updated sea level rise predictions, the researchers analyzed how beaches around the world would be in a future with higher seas and more damaging storms. They also considered natural processes like wave erosion, as well as human factors-like coastal building developments, all of which can affect a beach’s health. The study found that sea level rise is expected to outweigh these other factors, and that the more heat-trapping gases humans put into the atmosphere, the worse the influences on the world’s beaches are likely to be.

It’s hard to overstate just how important the world’s beaches are. They cover more than one third of the world’s coastlines, and protect coastal areas from storms. Beaches are also important economic engines, supporting relaxation, tourism and other activities. And in some areas, the beach is more than a vacation destination. In places like Australia, life near the coast revolves around the beach for much of the year.

Some of the world’s most popular beaches are already taking action. Places like Miami Beach are trucking in thousands of tons of sand to patch up (修复) badly eroded shorelines, while others have built sea walls and breakwaters in an attempt to hold precious sand in place. But the financial and environmental costs of these projects are huge, and scientists say rising seas and more powerful storms, supercharged by a warmer climate, will make this a losing battle.

However, the researchers did find that humans have some control over what happens to the world’s beaches. If the world’s governments are able to stick to modest cuts to heat-trapping gas pollution, the researchers found that 22%of projected beach losses by 2050 could be prevented, a number that grows to 40%by 2100 if greenhouse gases are limited.