Floods affecting much of the south-east US show the destructive force of higher sea levels and warmer temperatures. Now, researchers at the non-profit Climate Central are using artificial intelligence to predict how climate-related flooding will affect US communities into the next 75 years if warming continues at its current pace.
Previous research has shown that by 2050, sea levels along the US coastline could rise as much as 12in (30cm) from 2020 levels. High-tide flooding, which can occur even in sunny weather, is projected to triple by 2050, and so-called 100-year floods may soon become annual occurrences in New England.
The scale of the threat is difficult to fathom, said Ben Strauss, CEO and chief scientist at Climate Central. He hopes new AI imagery will help.
“We want to change how flood risk is communicated in this country,” Strauss said. “When the picture [is] of a local site that you know and are familiar with, that’s when the stakes really make themselves apparent.”
Climate Central sent camera-equipped trucks along the eastern and Gulf coasts to capture images and videos of flood-prone areas. Researchers overlaid the images with elevation data to create a real-time flood map that they say paints a clearer picture of current and future flood risks.
“Some people use AI to make deepfakes, but we use AI in a very controlled way to illustrate science projects,” said Strauss. “When we take a photograph, we analyze the position and the elevation of every single pixel in that image, and we force the AI to put water only up to the flood level.”
Climate Central shared images of iconic vacation destinations along the east coast – including Cape Cod and the Jersey shore – with the Guardian, visualizing how they will be dramatically altered by sea level rise and flooding.
The images depict water levels associated with 100-year floods, called that because there is a 1% likelihood of them occurring in a given year. However, these floods are increasing in frequency. Earlier this year, Maine experienced three 100-year-storms in the span of three months.
Melting ice caps are the main driver of sea level rise, which has gone up 4in in the last 30 years alone, according to the National Oceanic and Atmospheric Administration.
“Sea level rise raises the launch pad for coastal floods,” Strauss said. “So 1ft of sea level rise turns a 3ft flood into a 4ft flood. It also makes 3ft floods much more frequent than they used to be.”
Researchers used the Interagency Sea Level Task Force’s intermediate predictions for sea level rise, which project a rise of10 to 12in by 2050 and roughly 3ft by 2100 in the north-east. “Part of the future of sea level rise is all of the ice sheets and glaciers of the world catching up with the amount of warming that we’ve already caused, and a lot of that is what we see by 2050,” Strauss said. “Whereas up to 2100 you see a really big difference, depending on whether we heat up the planet more, or stabilize to near where we are.”
Researchers found one of the places that will be most affected by sea-level rise is Cape Cod in Massachusetts.
“On the Cape, all of our towns focus on flooding as the biggest risk – everything is at stake,” said Shannon Hulst, a floodplain specialist for Barnstable county in Cape Cod. “We’re both affected by the ocean, and the ocean drives our economy.”
An estimated 5.5 million people visit Cape Cod each year, bringing in some $730m to the local economy.
But rising waters are eroding the cape’s famous beaches. Hulst said: “If we don’t have beaches that draw in visitors any more, then our economy is going to look very different.”
Low-lying coastal areas like Cape Cod are at risk from tides, waves and storm surges.
Some are adapting by relocating inland; restoring coastal ecosystems like wetlands, beaches, dunes and oyster beds; elevating buildings and roads; and constructing sea walls. Residents are also flood-proofing their homes by raising their foundations or building on stilts, for example.
But while higher elevation can protect a property, that alone is not enough.
“Maybe your home won’t get destroyed,” said Nick Angarone, New Jersey’s chief resilience officer. “But if you can’t get out to get food and water, or if you lose power and you can’t get medical assistance and the rescuers can’t get to you, are you really resilient?”
Some residents in the flood-prone areas will eventually have little choice but to accept government buyouts of their homes, experts said.
Strauss said he hoped imagery like Climate Central’s will get people thinking about local resilience planning and their own emergency preparations.
“Even at the level of an inbound hurricane, we think that an image showing how deep the flood waters could be will be much more powerful in persuading people to evacuate and protect their lives than an emergency alert message in all caps,” said Strauss. “If they see that their house would be halfway underwater, that’s a different story.”