How Mapping Climate Outcomes Shows How Much We Can Save from Rising Seas

The most stunning thing about comparative maps of potential sea-level rise outcomes is not how much could be lost, but how much can still be saved. Scientific projections of future coastlines – depending on how much more the planet warms – reveal a world-changing opportunity: reducing pollution can keep vast expanses of coastal land above the reach of rising seas. And seeing the comparisons in a table doesn’t compare to the power of seeing them on a street-level map.

Mapping current projections shows cultural centers and economic hubs in megacities like New York, London, and Shanghai could be kept above the tideline if global temperatures peak at 1.5 degrees Celsius above pre-industrial norms. If global warming is held at 1.5 degrees, the resulting sea levels top out around 9-½ feet in the long run, over centuries. That would stop short of dozens of iconic neighborhoods along the U.S. East Coast, from Boston to Miami, and thousands more worldwide.

According to the United Nations, approximately 40 percent of the global population lives 100 kilometers from the coast. Our coastal hubs are important places that people love and rely on for their livelihoods, sometimes without living anywhere near them. As COVID slowdowns and shortages have shown, disruptions in ports and their links to supply chains can ripple through the global economy. Rising seas threaten to cause more frequent and more severe coastal floods in critical hubs, and the impacts can spread beyond borders, jacking up costs and even shutting down industries. But science shows that global climate action can dramatically reduce these risks, and with the stakes so high for so many, the financial incentives to act are immense.

Taking action means reducing carbon pollution, which makes climate change an unusually solvable problem: the steps to correct it are clear and achievable even without significant new technology. When the heat-trapping blanket of pollution around our planet stops growing, global temperatures will stop climbing. Because ice and oceans respond somewhat slowly to warming, the seas will keep rising for a time, but to a predictable (and mappable) level. Stopping warming at 1.5C would make a world of difference.

The pace of sea-level rise is accelerating, which ratchets up the costs to respond to it. Damages pile up faster as floods increasingly overwhelm protections. And protections themselves can become wildly expensive – even unaffordable – if they need to be built or built bigger in a hurry.

But the pace of sea level rise can be slowed by deep, rapid pollution cuts, giving coastal communities more time to plan and build – decades more. At that scale, financing major projects is less expensive, project scopes and costs are reduced, zoning and regulatory changes are less disruptive, residents and businesses have more time to prepare and adapt. In short, saving these places gets easier.

Studying climate change can be numbing, but seeing this opportunity can be inspiring. Mapping sea level rise projections shows how much control we still have over our future in a warming world. It visualizes the legacy our generation of leaders can leave by acting to hold back the water. It reveals how much power we have today over the shape and vitality of cities and nations centuries from now.

To see images and maps for yourself of how near-term climate action can shape the long-term future of coastal locations you know and love, please visit Climate Central’s Picturing Our Future and our Coastal Risk Screening Tool.