OSLO: From Copacabana to Cannes, from Miami to Waikiki, millions of dollars are spent on importing sand to raise beaches hit by storms, shifting currents and a rise in sea levels spurred by global warming.

In other parts of the world environmentalists want tighter regulation of sand dredged from the seabed to create beaches on previously rocky shores, believing the artificial shorelines disrupt the marine ecology.

Some low-lying Pacific Islands like Tuvalu fear they will disappear under the waves if global warming continues. But to what extent can humans keep the water out, as the Dutch have done with dykes, and at what cost?

“Beach nourishment is spreading from the Miami area, it may be a cancer going around the world,” said Charles Peterson, a marine expert and professor at the University of North Carolina.

“Beaches we’re looking at have not recovered as rapidly as suggested by official studies,” he said. “Alternatives have proven unattractive — sea walls, jetties and groynes — but there’s not been enough research into effects of new sand.”

He said that worms, clams, turtles and shorebirds find it hard to adapt to sand dumped on their habitats, especially when it is of a different type. He said imported sand should match the original as far as possible to minimise disruption.

In many cases, plants whose roots help create sand dunes and bind the beach together are often a better defence than big walls along the back of a beach, environmentalists say.

Beach building is likely to become even bigger business because of the demands of tourism — especially if global warming triggers new heat waves like in Europe this summer.

Almost no one favours letting nature take its course to gnaw away the coasts on a planet where more than half the world’s population lives within 60 kms of the shore.

The UN’s Intergovernmental Panel on Climate Change (IPCC projects that sea levels could rise by 13-94 cms by 2100 because of global warming pushing up temperatures by 1-3.5 degrees Celsius (2-6 degrees Fahrenheit).—Reuters