Mental stress on rise as coastal towns confront surging climate threats

When community leaders in the town of Piermont, just north of New York City, ask residents, "How long do you want to live here?" the question is more than a personal one.

Piermont, parts of which are set on a narrow peninsula that juts out into the Hudson River, is hugely at risk from rising sea level rise linked to climate change, and may become one of the early U.S. communities that need to retreat to higher ground.

Right now, flood walls can buy time. But in Piemont, "retreat has been on the agenda for a long time", said Kristin Marcell, who has helped residents discuss the idea as part of her job with the New York State Water Resources Institute.

As seas steadily swallow coastal land around the world, hundreds of experts gathered this week in New York for a first-of-its-kind global gathering on climate migration linked to land loss.

At the top of the agenda was a tough question: How soon will people want to move on when their homes and communities are at huge risk but not yet gone?

"Sometimes when talking to communities about retreat ... what they really, really want is for everything to be the way it was two decades ago," said A.R. Siders, an environmental fellow at the Harvard University Center for the Environment.

"And one of the harshest realities about climate change is that the future will not look like the past ... It will never be as safe, it will never be as secure and you will never be able to build the way your grandparents did."

Retreat due to natural hazards from storm surges to worsening cyclones has already begun, affecting 1.3 million people worldwide, said Katharine Mach, a scientist at Stanford University who researches climate risks.