How High Can You Build a Seawall?

SPEAKER_1 (0:00)

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Ben Bradford (0:15)

This is a story about water, and it couldn't be more timely. It comes out as we're again seeing the damage water can do. A hurricane in Florida and Alabama in the east, record El Nino waves lapping against homes in the west, and the question is, how much can we do to defy it?

A paper came out a few months ago in a top journal. The researchers who wrote it had Voltron-ed together from complementary backgrounds, a coastal geologist, a marine scientist, an anthropologist, an urban planner. They looked at sea level rise.

The seas are rising as the earth heats. Glacier ice is melting. Water itself expands as it gets warmer. The paper applied those physics to the city of New Orleans. New Orleans lies below sea level on an already watery fringe of southern coast. The paper did some straightforward math. It found that the last time the planet was similarly warm, back 125,000 years ago, when early people operated stone-wheeled cars with their feet.

And the paper asked, where was the coastline then? That's where it will be again, as the ice melts and the water expands. They found it far away.

Jesse Keenan (1:31)

The shoreline was dozens and dozens of miles north of where New Orleans is today.

Ben Bradford (1:37)

This is one of the report's authors.

Jesse Keenan (1:39)

I'm Jesse Keenan. I'm the Favreau Professor of Associate... I'm sorry, let me restart that.

I'm Jesse Keenan. I'm the Favreau...

Ben Bradford (1:49)

Jesse Keenan is a professor of urban planning at Tulane University in New Orleans.

I called him in particular because of that question I had. What are the limits of what we can build to defy nature? In this case, the sea. That's his background.

Jesse Keenan (2:04)

What can we do and what can't we do?

Ben Bradford (2:07)

His co-authors on the paper had found that the water will surge miles past the great American city where he works, New Orleans. Waves will lap on all sides surrounding it.

Jesse Keenan (2:17)

An island that's below sea level.

Ben Bradford (2:19)

The paper then said, and this is the part that caused uproar, it said, eventually, no engineering can save it.

Jesse Keenan (2:27)

The timing of that is open to an open debate in science. But there's an inevitability here.

Ben Bradford (2:33)

It could be decades. It could be a century. It could be longer. But Jesse's saying New Orleans will go underwater.

Jesse Keenan (2:40)

No matter what trajectory we pick, the region is heading in a direction where it cannot sustain the level of settlement that we have today.

Ben Bradford (2:53)

The paper came out and the reaction was swift, furious, bipartisan from the Republican chair of the state's Coastal Protection Board who called it the most ridiculous study I have ever seen, to local left-leaning journalists and commentators.

SPEAKER_4 (3:07)

New Orleans will never go away. There will be a system of dykes. There will be a...

It'll happen because money will protect it. It's too precious.

Ben Bradford (3:19)

I get this reaction. Let's not casually write off a city. People's homes are there. My cousins live there. And there's a particular sensitivity to New Orleans, obviously. With Hurricane Katrina, people experienced institutions not protecting them.

Still, none of that makes the engineering question disappear. The seas are rising. What are the limits of what we can build to defy it? And if there are limits, what then?

It's not just New Orleans. The rising seas are coming for where tens of millions of us live along coasts in this country alone. I'm one of them. The paper and the response really got me thinking about what this is going to be like, broadly. What are we going to do? Are we going to act in time? Is there a vision of the future where this country adapts well? What does that look like? That's what we're chasing today. The seas are rising. I want to know what a plan looks like to respond. How much can we build? What do we do when we can't? We'll start with New Orleans and the findings in that paper, but we'll scour the world for solutions. This is Are We Doomed from NuanceTales, distributed by the NPR Network. I'm Ben Bradford.

First of all, this headline that a city in America is going underwater and there's nothing we can do. Every fiber of me resists that. Plus, some solutions seem obvious to defy that projection. Before we do anything else, let's test those. Obvious solution one, do less climate change, stop the sea level rise.