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Biologist Warns Of Danger From Rising Sea Levels

In his new book, Flooded Earth, Peter D. Ward argues that even if humans stopped all carbon dioxide emissions today, the oceans will still rise up to 3 feet by 2050, wreaking havoc on many coastal cities and their infrastructure. In the worst case scenario, Ward tells host Guy Raz, the world may see water levels rise as much as 65 feet by 2300 causing massive human migration and a spread of tropical diseases.

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Transcript

GUY RAZ, host:

Welcome back to ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.

Peter Ward is a biologist at the University of Washington. He's not a historian but in his new book, "The Flooded Earth," he writes as a historian, but a historian describing the year 2120. And here's what happened to the city of Miami.

Professor PETER WARD (Biology and Earth and Space Sciences, University of Washington; Author, "The Flooded Earth"): (Reading) Miami had become an open city. It was also an island, although to the north it was still contiguous with the vast peninsula that had been Florida. The flooding had cut off all freeway and railroad ties while the airport itself was now a vast a lake. All this was because the level of the world's oceans had risen 10 feet.

The reason for this vast geographic change, one that rendered every school child's world atlas obsolete, was readily apparent: Greenland had lost its ice cover.

RAZ: That's Peter Ward reading from his new book, "The Flooded Earth." It paints a pretty bleak picture of how life on this planet will begin to change dramatically - as early as 2050, as sea levels continue to rise. Peter Ward joins me from KUOW in Seattle.

Welcome to the program.

Prof. WARD: Thank you so much for having me.

RAZ: You paint a picture of Miami. The city becomes kind of an archipelago of little islands, many islands, barely habitable. Is that really going to happen based on your projections?

Prof. WARD: It may not happen that early - that's the worst case scenario - but it will absolutely happen if we continue to be producing emissions at the rate that we are. I've now spent two field seasons in Antarctica. I've been able to look there at the recession of the glaciers and also of the ice sheets.

Remember, everybody worries about icecap, but ice floating on the sea, even if it all melts, has no direct effect on...

RAZ: Right. It's like ice in a glass. If ice melts...

Prof. WARD: Exactly.

RAZ: ...it doesn't change the level.

Prof. WARD: But, see, ice on land - and the two critical places are Greenland and Antarctica. I mean, those are really what we must worry about. I almost want to print out T-shirts: Keep the Ice Sheets, because we need to stabilize these.

RAZ: You focus on mass extinction of humans, of animals. You're saying that sea levels will rise - they rise every day, they're rising as we speak. What's the best case scenario by the end of this century in terms of how high the sea will rise?

Prof. WARD: Best case scenario that I can see is going to be a little less than three feet.

RAZ: So if we do nothing now, if we freeze...

Prof. WARD: We do nothing.

RAZ: ...mm-hmm. We do nothing, we freeze or emissions now, the seas will still rise by about three feet by the end of this century.

Prof. WARD: Three feet. And from all the engineers I've talked to - and it's been an interesting ride for me - civilization can deal with up to a five-foot sea level rise without major dislocation. But anything above five feet and you're talking tremendous economic and biological dislocation.

RAZ: Worst case scenario?

Prof. WARD: Worst case scenario would be five feet by 2100. But the problem with the five-foot rise, a sea level rise is something that doesn't take place at a constant level. It's accelerating. So once you have a five-foot rise by 2100, you might have a 50-foot rise by 2200.

So the five-foot rise would be catastrophic economically but it would also really be pointing the gun to the head of all of the coastal cities. Sooner or later, within a century or two after that, you're going to be dealing with triage, trying to figure out what do we save and what don't we.

RAZ: Where in the U.S. are we likely to see the effects? I mean, we think about, let's say, the Eastern Seaboard of the United States, and we can imagine what that looks like on a map, right? Will that look the same in 100 years?

Prof. WARD: In some senses. The place that will be most mitigated in terms of geography will be the entire Gulf region. I mean, that poor benighted place where we have all that nasty oil going to shore, that is the area where sea level will have the greatest impact.

RAZ: So when you talk abut the Gulf, are you talking about, for example, the Mississippi Delta?

Prof. WARD: Yes. The Mississippi Delta and every other delta on this planet is an endangered species. Deltas are completely tied into sea level. Even a one-foot rise in sea level tremendously affects the sedimentology of delta formation.

And here's why deltas are so important: an enormous proportion of the world's rice comes from the deltas in the tropical areas of the planet. When we have a rise even of a foot in sea level, we have many feet of lateral salt migration, the problem isn't the vertical rise of the sea. It is the fact that salt has this nasty habit of migrating sideways. And sideways into soil kills off agricultural crops.

Salt and plants that produce crops just don't mix. Mangroves, if we could eat mangroves, we'd be in great shape. But we're looking at this confluence, and this is why I'm so disturbed. We're looking at a global population that's going from 6.6 billion to nine billion. We're looking at a sea level rise from one to three feet, and we're looking at a reduction in arable land because of that sea level, so the equation is more people less food.

RAZ: You say that there are three possible outcomes of global warming. One, that scientists are wrong and that the icecaps won't actually melt; the second that the icecaps will melt but humans will adapt and they'll begin to cooperate; and the third is kind of a, I would call, "Mad Max" scenario where the ice caps melt and you have something akin to global anarchy. Which of these do you see as the most likely outcome?

Prof. WARD: I hope it's number two. I mean, this is just a hope. And we're looking back at history to try to understand how things happened and yet we've never had an industrial civilization of our level in history encountering rising sea level.

The fastest rise we know of in the past from Ice Age melting, though, is about five meters a century. So that's 15 feet in one century. We know from geological records it can go that fast. And this was in consequence to changes in atmospheric carbon dioxide far less than what we're doing now.

RAZ: And that would've been the results of volcanoes, for example?

Prof. WARD: What we're doing to the atmosphere now is very similar to what I studied in the deep past, which is that the Permian extinction and the Triassic extinction, when there were enormous volcanic vents of carbon dioxide in the atmosphere at rates that seem to be akin to what we're doing now.

Now, we just came through a horrible global recession and yet emissions globally did not reduce to where we hope they were. Even with the recession, emissions keep going up. Carbon dioxide levels keep going up. If we return to full employment, with all these extra people, what happens? Higher emissions, less ice sheet, higher sea level.

RAZ: Peter Ward, all of the scenarios you lay out are quite shocking and they're fascinating, but I wonder at what point does all you say become tangible, become something that people can actually see and be affected by, because, you know, one could argue that until that point, this is just theoretical and it's difficult to get people to respond and to make changes.

Prof. WARD: Look, what if we're wrong about the sea level rise? What will we have done to mitigate it? We will have searched for alternative forms of energy all good. We will have tried to do defenses on our coastlines, and with rising temperatures we're going to get stronger hurricanes; all good. So even if the sea level doesn't rise, the attempts to defense it are actually very powerful and positive things.

The alternative, doing nothing, well, maybe we'll get away with it. Maybe we'll dodge the bullet, but what if we don't?

RAZ: That's Peter Ward. He is a professor of biology and Earth and space sciences at the University of Washington in Seattle and author of the new book, "The Flooded Earth."

Peter Ward, thank you so much.

Prof. WARD: Thank you. Transcript provided by NPR, Copyright NPR.

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