For decades, waterfront property was some of the most desirable on the market. But a new report shows that if nothing is done to slow the march of climate changes, hundreds of U.S. communities will be seriously threatened by the end of the century. While today there are about 90 communities that face “chronic inundation,” that number could reach nearly 700 by the year 2100, including big cities and smaller towns on both coasts. Flooding is poised to become an important problem across the country within decades–and planners and designers will be on the front lines.
The study was published by the Union of Concerned Scientists, an advocacy organization that focuses on using scientific research to inform politics through papers on topics like clean energy, nuclear power, and climate change. This most recent report examines sea level rise that could cause flooding so frequent that it fundamentally disrupts the routines of a community. This is a measure called “chronic inundation,” which the union’s scientists define as when a community experiences flooding on 10% or more of its usable land every other week.
The report looks at three different sea level rise outcomes–one where emissions cause the ice sheets to melt significantly and cause 6.5 feet of sea level rise; one where there’s about 4 feet of sea level rise; and one where the world warms only two degrees Celsius (the goal of the Paris climate agreement).
In the most extreme scenario, the scientists found that 60% of waterfront towns and cities on the East and Gulf Coast will be chronically inundated by 2100. That includes more than 50 urban areas on coastlines, including Oakland, California; Miami; Charleston, South Carolina; New Orleans; and most of New York City.
It would start with higher tidal flooding, which means highways underwater, flooded basements and homes, and damaged vehicles. But as sea levels rise, the impacts would get more severe. Flooding could force people out of their homes and leave them unable to sell their property. Worse? The communities that sea level rise will affect the most are socioeconomically vulnerable, making them the least prepared for what is to come if climate change isn’t curbed.
In order to make the impact of the problem more visceral, the report is accompanied by a series of interactive maps created by the mapping software company Esri, which shows the impact of sea level rise based on these differing scenarios across the continental U.S. It allows you to watch different cities transform cartographically based on how much of their land is projected to be chronically inundated. The map of Charleston is particularly alarming–by 2100 in the extreme scenario, most of the city will be flooded so regularly it will be difficult for it to function at all.
Cities will increasingly be faced with difficult decisions: Should you continue to invest in areas where flooding is quickly becoming part of life, by building up infrastructure like levees? Or do you instead retreat, and essentially force people to move due to a lack of government investment?
The scientists provide what may seem like an obvious answer: fight climate change now so these problems don’t occur on such a vast scale in the first place. But their work is a reminder that cities and communities along the coast need to plan ahead. Planning for resilience from rising sea levels isn’t just the latest trend in urban design–it’s an imperative so hundreds of communities don’t drown.