Cities should consider ‘managed retreat’ to deal with rising seas, new study suggests

·Contributor
·3-min read
Rotterdam Skyline in sunset
The Dutch city of Rotterdam has installed floating homes that move with the tides, due to the threat of rising sea levels. (Getty Images)

Coastal cities should consider ‘managed retreat’ – even when it involves people abandoning their homes – in the face of rising seas, a new study has suggested. 

Adapting to a new world with higher sea levels will involve building floating neighbourhoods and cities, turning roads into canals or building denser, more compact cities on higher ground, University of Delaware disaster researcher AR Siders has suggested. 

Planners should be thinking 100 years in advance, Siders believes. 

Some projections of climate change - involving melting ice sheets - could see sea level rises of up to six feet, and hundreds of millions of people displaced. 

Siders said: “It’s hard to make good decisions about climate change if we are thinking five-10 years out. We are building infrastructure that lasts 50-100 years; our planning scale should be equally long.”

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Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked.

“We are looking at the different ways society can dream bigger when planning for climate change and how community values and priorities play a role in that.”

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Siders says that ‘managed retreat’ has already been used in the cases of Hurricanes Harvey and Florence, with homeowners near the Gulf of Mexico seeking government support for relocation.

In the Netherlands, Rotterdam has installed floating homes in Nassau harbour that move with the tides, providing a sustainable waterfront view for homeowners while making room for public-friendly green space along the water. 

In New York City, one idea under consideration is building into the East River to accommodate a floodwall.

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“If the only tools you think about are beach nourishment and building walls, you’re limiting what you can do, but if you start adding in the whole toolkit and combining the options in different ways, you can create a much wider range of futures,” Siders said.

“Communities, towns, and cities are making decisions now that affect the future. Locally, Delaware is building faster inside the floodplain than outside of it. 

"We are making plans for beach nourishment and where to build seawalls. We’re making these decisions now, so we should be considering all the options on the table now, not just the ones that keep people in place.”

The Kiribati government has bought land in Fiji for relocation and is developing programmes with Australia and New Zealand to provide skilled workforce training so the Kiribati people can migrate when the time comes. 

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