France's Aquitaine coast stretches north from the Spanish border to the Gironde river estuary, encompassing rocky bluffs, giant lagoons, deltas, beaches and Europe's largest dune.

Now climate change has laid siege to this natural oasis, dramatically speeding up the erosion of the 270 kilometre-long Atlantic coastline and threatening local communities.

A study published in 2006 by the European LIFE program identified 13 coastal communities as erosion "hotspots".

"There is a lack of sand on the beaches, because of a period of warming - climate change," confirmed Cyril Mallet, geological engineer and project manager for the French geology and mining research agency BRGM.

Climate change means rising sea levels, more violent storms and increasing rainfall in a region already suffering from its location on the Bay of Biscay, where ocean waves carry 500,000 cubic metres - about 200 Olympic swimming pools - of sand southward every year.

Cliffs are sliding into the sea, beaches are disappearing, dunes that protect forests, towns and roads are in danger, and the tourism trade is in jeopardy, local experts said.

The stakes are high.

Only 10 per cent of the coast is populated, but that population is growing, and between May and September, visitors spend more than €1.4 billion in surfing beaches, spa towns, ocean side campsites and quaint villages.

The pristine beaches are the first casualty of coastal erosion.

"Tourism is our economy," said Albery Larrousset, Mayor of Guethary, a Basque town of 1,300 whose population swells to 5,000 in the summer months. "And without beaches, we won't have tourists."

Parking lots, businesses, roads and homes are planned with the notion that beaches remain in one place.

Traditional defences like seawalls increase erosion in neighbouring areas, denying the towns easy remedies. Solutions are as varied as the communities involved, but nearly all require moving sand from one place to another.

Near the northern tip of the coast, Soulac-sur-Mer is a popular beach and camping area. A year-around population of 2,800 expands to 40,000 in summer.

The town, roads and campgrounds are in danger from erosion, and one campground clings precariously to the beachside location.

Locals do not want to hear about retreat, but the damage forces a town employee to redistribute sand over an 800-metre section every day.

Farther south, Arcachon Bay has taken a different approach.