Climate heat’s tides may rise above safety levels

Managed retreat in eastern England: The sea wall has been breached to let the tides create a saltmarsh lagoon protecting more valuable land further inland. Image: By Glyn Baker, via Wikimedia Commons

Millions will either have to flee from climate heat’s tides, or find new ways to stay above water.

LONDON, 21 June, 2021 − If global heating is not to be stopped − which seems the case − then governments, civil authorities and communities must start thinking of ways to live with it, including how to survive climate heat’s tides.

That could mean building floating cities that will bob up and down with the tides, or existing cities in which the streets have become canals and the parks have become lakes. It will also mean, as land is surrendered to the sea, that cities will have to become more compact, and more crowded, on higher ground.

It could also mean urban forests and vertical forests: skyscrapers with balcony gardens, orchards and micro-wildernesses all the way up. It could mean that farms convert to aquaculture: where saltmarsh lamb once grazed, farmers might raise shrimps and shellfish.

This is called managed retreat. As the polar icecaps melt, temperature extremes rise, droughts multiply and floods and superstorms become ever more intense, humans will have to adapt.

“Climate change is affecting people all over the world. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked”

By 2100, at the most conservative estimate, around 88 million people could be forced to relocate, as the high tides get ever higher, and the seas begin to erode or invade the world’s coasts. At the most alarming estimate, the numbers of displaced persons could rise to 1.4 billion.

“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,” said A R Siders, of the Disaster Research Center at the University of Delaware in the US.

“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.”

She and a colleague argue in the journal Science that in a small way managed retreat has already begun: in the US some 45,000 families have been helped to move out of flood-prone housing in the last 30 years, and “this represents a tiny fraction of the millions at risk and is fewer than the number of homes experiencing repeated damage and the number of new homes built in floodplains.”

The point is that much climate thinking is still short-term. “It’s hard to make decisions about climate change if we are thinking 5-10 years out. We are building infrastructure that lasts 50-100 years; our planning should be equally long,” Dr Siders said.

Living with risk

The researchers list the challenges ahead: communities that live near the wild lands must learn to live with the increasing threat of forest fires; city dwellers in the warmer climates could have to face potentially lethal extremes of heat; low-lying island nations in the Pacific may have to transfer whole populations to other countries.

Some low-lying coastal cities have already begun to adapt: Rotterdam in the Netherlands already has floating homes in Nassau Harbour that rise and fall with the tides. New York City, hard hit by Superstorm Sandy in 2012, is contemplating a floodwall in its East River.

Flooding on the US Atlantic coasts is expected to get worse: millions of Americans will probably have to migrate inland or become climate refugees. Dr Siders and colleagues began urging strategies of what she calls planned retreat two years ago.

At least one US Atlantic settlement could be be swept away or inundated by mid-century. For the people of Delaware, the problems are immediate.
“Communities, towns and cities are making decisions now that affect the future,” Dr Siders said.

“Locally, Delaware is building faster inside the floodplain than out of it. We are making plans for beach nourishment and where to build sea walls. We’re making these decisions now, so we should be considering all the options on the table, not just the ones that keep people in place.” − Climate News Network.