The G7 Is Meeting On A Vanishing Coastline, French Scientists Warn World Leaders

BIARRITZ, France—Scientists from Southwest France warned world leaders this weekend at the G7 Summit that the picturesque shoreline where they are meeting could retreat 100 meters in this century because of rising seas.
Thirty scientists from the region collaborated on a report on coastal vulnerabilities that local elected officials delivered to French President Emmanuel Macron Saturday as heads of state arrived from around the world.
"The coastal regions welcoming this major political and diplomatic event are calling for international cooperation to consider the protection of the oceans and the sustainable use of their resources a new frontier, an emergency and a shared challenge," said Alain Rousset, president of the regional council of Nouvelle-Aquitaine, in a letter also signed by the heads of two departements and the mayor of Biarritz.
Each centimeter of sea level rise roughly corresponds to a meter of coastal retreat, according to Eric Chaumillon, a senior lecturer in geology at the University of La Rochelle and a specialist in the environment of shorelines and sandbanks.
The impact varies according to terrain, but Chaumillon anticipates at least 30 meters of coastal retreat this century and possibly as much as 100 meters. So far, he added, measurements have exceeded scientists' estimates.
The sandy coast has receded one to three meters per year and the rocky coast around 0.25 meters per year, according to Alexandre Nicolae Lerma, a research engineer at BRGM, the French Geological Survey. The rocky coast, however, can lose 25 meters in a single collapse.
The heads of state are meeting at the Hotel du Palais Biarritz in a rotunda 20 meters from the high-tide line.
"Adaptation to the effects of climate change on coastlines is not only necessary but has to be implemented concretely from now on," the scientists warn in their report, which was also given to the leaders of Canada, Germany, Italy, Japan, the United Kingdom and the United States.
For his part, Macron has scheduled a working session on oceans, climate, and biodiversity for Monday morning.
He will ask the heads of state to sign the Metz Charter on Biodiversity, which French officials say "should send a strong signal" in response to another recent warning from scientists and "enshrine a commitment" to stop the collapse of biodiversity.
Macron has also invited heads of state from Australia, Burkina Faso, Chile, Egypt, India, Rwanda, Senegal and South Africa to participate in the environmental appeal.
Chaumillon recommends restoration of coastal wetlands, which, he says, can limit water levels and dampen waves—especially when planted with mangroves and coastal-marsh vegetation. Wetlands also permit sedimentation that adapts to continuing sea level rise, serve as a nursery for many species, provide resting habitat for migratory birds, clean groundwater and surface water, and excel at storing carbon.