Adapting to Climate Change

The program explores ambitious plans being made to deal with future catastrophic events and shifting weather patterns

No matter what you believe about climate change, we can all agree that extreme weather events—tornadoes, hurricanes, fires, droughts—are occurring more frequently. These massive natural disasters upset lives and devastate property. The costs of cleanup and reconstruction are enormous.

“Adapting to Climate Change” explores the ambitious plans that engineers, scientists, government officials, business leaders, NGOs, and community groups around the world are making to deal with future catastrophic events and shifting weather patterns.

This one-hour special is cohosted by PBS documentarian Rick Karr and IEEE Spectrum’s Susan Hassler, and is part of the “Engineers of the New Millennium” series.


Susan Hassler: Hi, I’m Susan Hassler, and this is “Engineers of the New Millennium: Adapting to Climate Change.”

Rick Karr: And I’m Rick Karr.

Susan Hassler: No matter what you believe about climate change…

Rick Karr: …what’s causing it, whether it even exists…

Susan Hassler: …I think we can all agree that something is happening.

Rick Karr: Something we’re not prepared for.

News voices: People across the South are digging out from a surprise.…Forecasters knew there would be snow but missed their calculations on where and how much.…Scores of tornadoes rolled across the middle of the country yesterday, picking up cars, flipping farm equipment, smashing buildings.…Last Friday’s storm was one of the most powerful ever recorded on land. The U.N. says the death toll from that massive storm is around 3600.…

Susan Hassler: Extreme weather—tornadoes, hurricanes, fires, droughts—is striking more and more frequently.

Rick Karr: And it’s costing us dearly, taking lives, destroying homes, whole towns, and regions.

Susan Hassler: The expense is huge.

News voices: To judge by Times Square today, Sandy seemed to be more of a myth, but downtown, it’s clear the Big Apple took a big hit.…The system that carries 5 million riders every day, still a deluged tunnel of darkness.…Block after block, mile after mile of this kind of ruins.…

Rick Karr: Today we’ll explore ways to cope with increasingly severe weather…

Susan Hassler: …and defend ourselves from recurring natural disaster.

Rick Karr: Our program is a coproduction of the Directorate for Engineering of the National Science Foundation and IEEE Spectrum.

Susan Hassler: We begin by looking at one city that’s found it has to act now.

Michael Bloomberg: I strongly believe we have to prepare for what scientists say is a likely scenario. Whether you believe climate change is real or not is beside the point. The bottom line is, we can’t run the risk.

Ariel Bleicher: That’s Michael Bloomberg, who was mayor of New York City during Hurricane Sandy, in 2012.

Susan Hassler: And this is Ariel Bleicher, our reporter in New York.

Ariel Bleicher: Hi there.

Rick Karr: Want to set the scene for us, Ariel?

Ariel Bleicher: So, in October of 2012, New York City was hit by one of the worst storms in U.S. history: Hurricane Sandy. It slammed the coast with a surge as high as two stories.

Susan Hassler: The water was wildly destructive. Subways shut down, millions of people lost power, hospitals were evacuated.

Rick Karr: The economic cost? About [US] $19 billion.

Ariel Bleicher: So Mayor Bloomberg assembled a team of climate experts and city planners who could create strategies to defend the city from a storm like Sandy in the future.

Susan Hassler: So we’ll take you to New York to see what a city can do to face the threats of climate change.

Rick Karr: We’ll look at pros and cons of the plan, and explore what other cities can learn from it.

Susan Hassler: Ariel starts us off in a distinctly untouristy part of the Big Apple.

Fish seller: I’m working here, baby! I’m working here!

Ariel Bleicher: It’s 4:00 a.m., but here in an industrial pocket of the South Bronx called Hunts Point, the fish market is bustling. Inside a huge warehouse, buyers and sellers haggle over prices. Workers weigh orders, sort inventory, and hack fillets with big, sharp knives. Everywhere, piled on the floor and on tables, are cardboard boxes filled with ice and fish, lots and lots of fish.

What are you selling here?

Fish seller: I sell wild king salmon out of Alaska. I sell farm-raised New Zealand king salmon, ocean trout, bronzini, frog legs.

Ariel Bleicher: And it’s not just fish that are traded here.

Susan Hassler: The Hunts Point market includes more than 300 acres of warehouses, where you can find pretty much any wholesale product you can think of: meat, vegetables, fruits, nuts, beer.

Rick Karr: More than half the fresh food consumed in New York passes through here.

Ariel Bleicher: The problem is that this distribution center, so vital to New Yorkers, sits on the tip of a peninsula.

Rick Karr: It’s almost entirely surrounded by water.

Susan Hassler: According to FEMA, the Federal Emergency Management Agency, about a thirdof the Hunts Point market is in the high-risk zone called the “100-year floodplain.”

Ariel Bleicher: Which means that in any given year, it has a 1 percent or greater chance of flooding.

Rick Karr: And as the climate warms and sea level rises, that 1 percent will increase. Floods will worsen and occur more frequently.

Susan Hassler: New York and a lot of coastal cities face this problem: How do you protect vital infrastructure that sits in the 100-year floodplain?

Rick Karr: That includes thousands of homes and businesses, telecommunication equipment, power plants, sewage treatment plants, gas stations…

Susan Hassler: …and subways.

Worker: Be careful, because the stairs are steep.

Ariel Bleicher: And subways.

Wynton Habersham: Yeah, the best way to come down these stairs is backward.

Ariel Bleicher: Wynton Habersham is the chief electrical officer with the Metropolitan Transportation Authority. He takes us into the Montague Tunnel.

Wynton Habersham: Watch your step there.

Ariel Bleicher: This tunnel carries the R train under the East River, between Brooklyn and Manhattan. Hurricane Sandy flooded it, top to bottom.

Wynton Habersham: Because this under-river tunnel that goes from Brooklyn to Manhattan was totally submerged, 28 million gallons of water, all of the equipment, the signal equipment, the pumping equipment, the fan plant controls, the tunnel lighting, all the cables, power cables, traction power cables, circuit breaker houses—all of that equipment was all submerged and damaged.

Ariel Bleicher: It will take more than a year and $100 million to replace it all. Hurricane Sandy was kind of a wake-up call for the city to reassess its vulnerability. The city assembled a panel of climate scientists to assess what natural threats New York would likely face in the future: the number of days above 90 degrees, for example, or the frequency of floods.

Radley Horton: I’m Radley Horton. I’m a climate scientist from Columbia University’s Earth Institute.

Ariel Bleicher: Horton and the other scientists studied the latest data on sea-level rise and found that very small changes—like the average daily temperature getting just a bit warmer, or the ocean rising slightly…

Radley Horton: …can in itself give you a rapid change in the frequency of extreme events.

Ariel Bleicher: Just a foot or so of sea-level rise by the 2050s could mean that really bad floods will happen three, maybe even five, times as often as they do today.

Rick Karr: So we should expect more hurricanes like Sandy?

Ariel Bleicher: Not necessarily.

Radley Horton: So, you don’t need a lot stronger hurricanes; you don’t need stronger hurricanes at all.

Ariel Bleicher: Horton says that in the future, New York could get Hurricane Sandy–like flooding from average storms. Basically, as sea level gets higher, it raises the bar. So even fairly small waves could push a lot of water into the city.

Rick Karr: Okay, so if New Yorkers are looking at worse flooding and more of it, what can they do about it?

Ariel Bleicher: Well, part of the challenge is choosing what engineering solution will work best. You’ve got surge barriers, levees, bulkheads, floodwalls, and sand dunes. You could build rocky slopes called revetments that help break waves. Or in some cases, you could turn some of your coastline into wetlands or oyster reefs. There are lots of options.

Susan Hassler: So New York asked scientists and consultants to test out different solutions.

Ariel Bleicher: They used an ocean model to simulate the impact of a storm surge on coastal communities all over the city. They plugged in various engineering solutions to see which ones worked best to stop or slow the surge.

Susan Hassler: Then the team took all that science, decided what it could afford, what was most feasible, and came out with a 438-page report.

Rick Karr:It’s more like a book, really, with a grand total of 257 specific recommendations of things the city plans to do.

Ariel Bleicher: It’s a huge list. A lot of those 257 initiatives are coastal protections. And the work has begun. On Staten Island, for example, on a beautiful little beach called Cedar Grove, construction crews are out building huge shelves of sand called berms. They line up big black plastic bags, fill them with rust-brown sand that’s been trucked in from New Jersey, and then pile more sand on top of the bags. So during a storm surge, that sand shelf should stop the water from flooding all the homes behind it.

Susan Hassler: We should say, though, that the city’s plan isn’t just about protection, about keeping the water out.

Ariel Bleicher: Right, the word the report emphasizes is resiliency.

Rick Karr: In fact, the title is “A Stronger, More Resilient New York.”

Daniel Zarrilli: Resiliency is really about being able to absorb the risks that are coming your way, and being able to bounce back quicker.

Ariel Bleicher: Daniel Zarrilli, the city’s director of resiliency. He has to see that all those 257 initiatives get carried out.

Susan Hassler: We’ve heard about coastal protections. But these initiatives also include things like changing construction requirements for new buildings, educating people about flood insurance, and working with utilities to harden essential equipment like train switches.

Daniel Zarrilli: There’s no one silver bullet. There’s no one answer to the risks that we face. And so we instead, I think rightly so, have laid out a “multiple layers of defense” strategy.

Ariel Bleicher: First line of defense: coastal protections. But say those get compromised—a tide gate breaks or a levee gets breached.

Daniel Zarrilli: Now your buildings, your homes and buildings, have either raised their mechanical systems, have raised entire buildings, have put in place resiliency measures that can make them more able to handle the water or the waves that may be coming past the coastal defenses.

Ariel Bleicher: A lot of New Yorkers, including climate experts, really like the plan. But…

Malcolm Bowman: But I would then say, “Look, it’s not enough.”

Ariel Bleicher: That’s Malcolm Bowman.

Malcolm Bowman: I’m a distinguished service professor of oceanography at the State University of New York at Stony Brook.

Ariel Bleicher: Bowman is a vocal critic of Bloomberg’s plan. He says that all those initiatives that the city wants to get started on—building up the beaches, raising mechanical equipment, hardening sewers and subways—all those local projects are a good thing, most of them are necessary.

Malcolm Bowman: But they’re not sufficient. We say in science that something is necessary, but it’s not sufficient. That means it’s not enough.

Ariel Bleicher: Bowman says that New Yorkers shouldn’t just make their city stronger. They should protect it and do what London, Venice, and St. Petersburg have done—build massive storm barriers to stop flooding altogether.

Malcolm Bowman: What I’ve been proposing for New York City is actually two barrier systems.

Ariel Bleicher: One barrier would be north of the city, in the upper East River. It would protect Hunts Point, that food market we visited earlier.

Susan Hassler: And the other one would stretch 5 miles across the southern harbor to the New Jersey coast.

Malcolm Bowman: It’s more like a series of bridges, because you must let the tide flow in and out as normal during good weather to allow the flushing of the harbor for marine life, the fisheries, and so forth. Then, where the shipping channels are, there are two large swinging gates. They call them “saloon doors” because they swing open and close when necessary. They’re open most of the time—in fact just about all the time—but maybe close for a few hours at the height of a storm, and they swing shut. And it just keeps the water out. It’s a very simple engineering idea. It’s not rocket science. It’s just good engineering.

Ariel Bleicher: Bloomberg’s team rejected the big barrier idea because it could take decades to build. And it would cost about $25 billion. The total cost for the current plan is about $20 billion.

Susan Hassler: Another problem with barriers around the city is complacency. Daniel Zarrilli says that people can forget that flooding and sea-level rise is a problem.

Daniel Zarrilli: And that gives a false sense of comfort—maybe I don’t have to raise the elevation of my house, maybe I don’t need to make improvements to the tunnels in the city, maybe we don’t need to do all these other things that are vitally important. I think it’s a dangerous concept that we can put all of our eggs in that basket and expect it to make us safe.

Susan Hassler: Do New Yorkers expect the city to keep them safe from severe storms? We took to the streets and asked them.
Voices of people on the street:
“I think they’re trying. I think the city does better than most. For a big monstrous city, I think we do a fairly good job with it. An unfortunate reality of the way the environment is today, you’re gonna see more and more of them. The key is to be a little more technically prepared to deal with them.”

“They’re definitely something to be prepared for.”

“We’re surrounded by water, so the best thing we can do is build some kind of perimeter around the island, some type of fortress, just in case you get high tide waves coming in.”

“I think they should come up with plans with how they’re gonna handle the storms, because while you can to an extent rely on the city to protect you and find you shelter, there’s a certain limit to that.”

Rick Karr: We’re back with more “Adapting to Climate Change” in a moment.

Susan Hassler: We’re back with “Adapting to Climate Change.”

Klaus Jacob: If you just think, Oh, now I am safe because I have this protective structure and go to sleep, well there will be a bitter awakening.
I’m Klaus Jacob. I’m a special research scientist at the Lamont[-Doherty] Earth Observatory of Columbia University, in Palisades, N.Y.

Ariel Bleicher: Jacob is another critic of the city’s plan. He agrees with Zarrilli that massive barriers across the harbor aren’t the right solution. But he also agrees with Bowman that the current plan doesn’t do enough to protect future generations from flooding.

Klaus Jacob: So the question then: What is missing in the plan? Missing in the plan is the big, long-term vision of the city.

Ariel Bleicher: Right now, New York City’s resiliency plan looks about 35 years out to the 2050s. But the city climate change panel projects that by 2050, really bad floods, like those from Hurricane Sandy, could happen every 20 or 30 years.

Klaus Jacob: And eventually, if you go beyond 100 years, it will be flooded permanently!

Rick Karr: So what’s the alternative?

Klaus Jacob: Let the water in. Invite it in! Don’t fight the water. It’s very difficult in the long run to fight water.

Ariel Bleicher: Even if New Yorkers do all they can to protect the waterfront and make it more resilient today, eventually, the water will be here to stay. And New Yorkers will either have to move their homes and businesses to higher ground…

Klaus Jacob: …or modify them in such a way that we can live in the water.

Ariel Bleicher: You could imagine water taxis, maybe even amphibious buses, elevated walkways.

Klaus Jacob: And you walk from building to building, and you look down into Wall Street where there’s the water, and the ducks swim around and maybe some harbor seals. It will actually be a very nice, interesting water city. We just have to think it in that way. Now, that will not happen in the next 50 or 100 years, but it will be inevitable somewhere beyond 100 years.

Rick Karr: So if that’s true, future generations of New Yorkers will have to retreat from the coast or live in the water.

Susan Hassler: That’s a change New York needs to plan for. And other coastal cities may have to adapt a lot sooner than New York.

Ariel Bleicher: But some of them simply won’t have the money for the protections and hardening measures that are in New York’s plan.

Rick Karr: And some places don’t have the right geology to build coastal barriers. In south Florida, for example, a lot of the shoreline is limestone, so even if communities had the money to build walls, the water would just percolate underneath.

Susan Hassler: Well, it sounds like there are lots of options but no silver bullet. Thanks, Ariel.

Ariel Bleicher: Yup. Sure thing.      

Rick Karr: We began our show in New York City, where more than 8 million people live within a mile or two of the coast.

Susan Hassler: But it’s not just New Yorkers who prefer to live near the water. John van de Lindt is a professor of engineering at Colorado State University.

John van de Lindt: Fifty percent of the U.S. population lives within 50 miles of the coast, and so they’re susceptible to these large storms, things like we saw with Superstorm Sandy. And really, a big issue is, as sea levels rise, the buffer zone becomes smaller and smaller.

Rick Karr: And where there are people, there are buildings, houses, grocery stores, office plazas, movie theaters, restaurants, and so on. Van de Lindt spends a lot of time thinking about what impact increasingly harsh weather will have on these buildings.

John van de Lindt: There’s a very solid understanding at this point of how the waves or the surge and the wind interact with the coastal infrastructures.

Susan Hassler: And that means it’s now possible to prepare for major weather events.

John van de Lindt: The biggest issue with doing something like that is determining not necessarily the weakest pieces to the infrastructure, but what’s the most vulnerable to prevent loss of life and really put government dollars and public money where it has the most impact.

Rick Karr: For instance, van de Lindt says coastal houses can be made safer simply by installing hurricane clips. Those are metal straps that secure a building’s roof to its walls and walls to its foundation, and that help channel the force from high winds through the building and into the ground.

Susan Hassler: The clips can be installed by homeowners themselves for a few thousand dollars. For larger buildings on the coast, there are options that are just as simple, but they just cost more.

John van de Lindt: It’s certainly millions and into the billions of dollars to retrofit the infrastructure. If it’s a concrete or a steel building, usually they’ve been well engineered. And so the biggest cost for some of those buildings would be shatter-resistant glass, things like that. And then for a bridge, many, many bridges are what we call “functionally obsolete,” or they’re “deficient,” things like that. And so really the answer for a lot of those is to build a new bridge beside it, and then once it’s in place, take the other one down.

Susan Hassler: Now, it’s important to point out that it’s not just the coasts experiencing the effects of climate change.

News voices: Akron is another area hit hard by tonight’s storms. Many people are dealing with flooded streets and homes….All that rain could have come in handy in Colorado, where a series of dangerous wildfires is raging on this morning. The flames are spreading now.…It’s now official: We are living in one of the worst droughts of the past 100 years. The part of our country we call the Breadbasket—the section of the U.S. that feeds its share of the world—is burning up right now.

Rick Karr: In the midst of all this crazy weather, we’re going to touch down in the heartland of the U.S.—in Iowa City, Iowa.

Jerry Schnoor: The climate is changing already. It’s already here.

Rick Karr: Jerry Schnoor is a professor of environmental engineering at the University of Iowa.

Jerry Schnoor: We’re located right at the middle of the country, so near the dividing line between the arid West and the more wet eastern part of the United States. And we’re experiencing both kinds of extreme weather. We’re seeing too much water and too little water at different times of the year. Right now we’re in a severe flood, but last year we had severe drought—the worst since the 1930s.

Susan Hassler: Flooding is a real issue out here in farm country, because the water washes away rich topsoil that’s needed to grow crops.

Jerry Schnoor: So far in the Midwest, just roughly, we’ve lost maybe half of all the topsoil that has been developed since the last glaciation more than 10 000 years ago.

Rick Karr: Schnoor’s research focuses on adaptation. That is, sustainable approaches to dealing with climate change in Iowa.

Jerry Schnoor: I refer to three kinds of sustainability: the economic profitability of the farmer, the environmental sustainability of holding soil and nutrients on the land and not running off into, say, the Mississippi River, and thirdly, social sustainability such that the communities, the jobs, are preserved for the future.

Susan Hassler: Schnoor calls this the “triple bottom line,” one in which profit, people, and the planet all benefit. To figure out how to make this a reality, he’s working to create something called an intelligent digital watershed.

Jerry Schnoor: It would be a tool for monitoring, modeling, and forecasting water quality, and to some extent, water quantity, well into the future. Ideally we would like to put the farmers in the loop so that they could actually sit at their television screen if it was streaming to their home, or even sit with us at a computer and change their farm field by field in terms of what they plant or how they manage the land, and get back the result of how their yield would change, and even their profits from that particular year might change. And thus that would help them make their decisions about, “Oh, if I planted a different crop, I could maintain my profitability and improve water quality at the same time.”

Susan Hassler: To design his digital watershed and make his predictions, Schnoor is combining three ingredients. The first is data.

Jerry Schnoor: We make use of satellite data, the rainfall data, Nexrad [next-generation] radar, the best mathematical models, and high-performance computing.

Susan Hassler: The second ingredient is the farmer’s thought process. That is, how they make decisions.

Jerry Schnoor: We obtain that data by surveying the farmers, and it has to do with what crops they plant, how much fertilizer they use, what tillage practices they may choose. Whether they agree that climate change is due to humans or not, they recognize that the weather patterns are changing. For example, they’re planting much earlier than they used to, and oftentimes they’re harvesting earlier as well.

Rick Karr: And now for the third ingredient, social sustainability—maintaining jobs—we go off campus. Jerry Schnoor is at the wheel, and he’s got a couple of his doctoral students in the car. He drives to a field site on Muddy Creek, a meandering stream north of Iowa City.

Jerry Schnoor: Where should I park? Good question. I may park along the side of the road here—I’ll put on the flashers.

Susan Hassler: The team hops out of the car. This is near the end of Muddy Creek, just 100 feet or so from where it joins up with the Iowa River.

Jerry Schnoor: There’s our sign. “University of Iowa property. Do not touch. Research in progress.”

Muhieddine Kabbani: Okay, we need to go down.

Susan Hassler: Muhieddine Kabbani, a Ph.D. student, shuffles down the embankment to the side of the creek and stops in front of three tubes lying flat, each one half his height and with one end touching the water. The tubes contain a suite of sensors that measure pollutants.

Muhieddine Kabbani: The sensors here are continuously measuring the pollutants in the river.

Jerry Schnoor: Also one for clarity, turbidity. One is for measuring nitrate, and also one for dissolved oxygen. These sample every 15 minutes and allow us to monitor storms as they arrive and recede.

Rick Karr: The sensors are powered by a set of solar cells, and the data they record is beamed back to the lab in real time. And that makes life pretty nice for Muhieddine Kabbani.

Jerry Schnoor: Muhieddine, he can sit at his desk in his office and receive the water-quality information every 15 minutes and watch it coming in if he wants to.

Muhieddine Kabbani: And from there we can know exactly what’s going on in the creek.

Rick Karr: It’s this water-quality information that’s the final ingredient for Schnoor’s intelligent digital watershed. By tracking nitrate runoff every 15 minutes, for example, Schnoor and Kabbani can calculate how much fertilizer is leaving the farms and ending up in Muddy Creek. That information’s important for the digital watershed to make smart predictions in the future.

Muhieddine Kabbani: We need to calibrate our model to real data.

Susan Hassler: But there’s a real cost to that runoff too, both to the farmers, who’d rather keep the fertilizer in their fields to help the crops, and to the surrounding environment, where it becomes a form of water pollution.

Rick Karr: This creek joins the Iowa River upstream of the treatment plant for Iowa City’s water supply. If pollutant levels are high here, treatment has to increase.

Muhieddine Kabbani: In that way, we are having a clear picture exactly what we are having as pollution at the very last accessible point in the creek.

Susan Hassler: The sensors measuring pollutants have to endure all kinds of water levels—from droughts, when the creek is no more than a thin thread, to floods.

Jerry Schnoor: Each set of sensors costs about $20 000. So we’re hoping that the storm doesn’t get so violent that it carries them away. We’re hoping that hunters don’t shoot at them.

Muhieddine Kabbani: That’s why we put all these anchors around.

Jerry Schnoor: Because it is quite expensive.

Rick Karr: The team gets back in the car to drive to the next water sampling site on Muddy Creek. Through the windshield, Schnoor spots a pond off to one side of the road.

Jerry Schnoor: That’s the conventional way that we control storm runoff, is with these detention ponds. Climate change affects it because the storms are getting more intense here. A hundred years ago, it was very rare for us to get a 4-inch rainstorm in a single day. Now it’s not uncommon at all. On April 17, this area where we are right now got almost 7 or 8 inches in a single 24-hour period.

Susan Hassler: Schnoor parks the car and wanders down to a section of the creek near an overpass, commenting on the ecological effects of new construction of buildings and parking lots.

Jerry Schnoor: This stream is quite urban and urbanizing, and we’re interested in the role of the urbanization that occurs and the impacts on the water quality.

Rick Karr: Schnoor’s solution in response to all the pavement and asphalt is to find ways to slow the water down—to let it soak into the ground, by giving rainwater access to the soil…

Jerry Schnoor: …by using green infrastructure, using green roofs, rain gardens, porous pavements, and wetlands to detain the water longer.

Rick Karr: Planning this kind of green infrastructure is another reason that Schnoor and his students are sampling the creek out here so aggressively—to understand how much water’s flowing and what’s dissolved in it. And sometimes they do the sampling by hand.

Jerry Schnoor: This is what we call just grab sampling. These are the type of samples that we don’t take automatically but rather on a schedule. Maybe biweekly we’ll come and take a sample just to get an idea of the seasonal variation through time of the creek.

Susan Hassler: One of Schnoor’s other students tosses a plastic cup into the stream.

Lance Le: I’m Lance Le. I’m a Ph.D. student in environmental engineering at the University of Iowa. And my research is about watershed-scale hydrology modeling.

Susan Hassler: The plastic cup is connected to a rope, which allows Le to retrieve water from the middle of the flow.

Jerry Schnoor: Pour it in there, Lance.

Susan Hassler: He pours a clear stream of water into a flask.

Jerry Schnoor: You can see that Muddy Creek is a misnomer at this particular point because it’s largely spring water. It’s not muddy at all, at least not right now. In a rainstorm it would be, even here near the source, and the runoff would overshadow this nice spring water that we’re looking at.

Rick Karr: Back in the lab, Schnoor can watch the various data streams flow together, joining forces as they enter into his intelligent digital watershed.

Jerry Schnoor: And we take all of that information and we run the model out 50 or 70 years to see how sustainable the system is in the future. The whole idea of the science is to better inform decision-making.

Susan Hassler: And yet his predictions can vary a lot depending on which climate reality Schnoor and his students select.

Jerry Schnoor: There are various different scenarios, so we look at the possibility of it becoming much, much wetter and the possibility of it becoming wetter but punctuated by pretty severe droughts. Those are different storylines that are run through the computer, and it would cause you to have a different plan of action in how you’re going to adapt to the climate change.

And so that means that we have to prepare. We have to adapt to both the possibility of flooding and droughts. And that’s a very difficult situation for farmers and for the Environmental Protection Agency or water-quality planners at the Department of Natural Resources to deal with. And that’s sort of the conundrum of climate change, that we could be presented with both problems. And that becomes much more difficult to plan for.

Rick Karr: One thing that Schnoor is able to predict without difficulty is that we’re going to need a lot more of these adaptation measures if we keep up our business-as-usual behavior and continue releasing carbon dioxide out of our tailpipes and smokestacks.

Jerry Schnoor: Adaptation and mitigation are two sides of the same coin. If we don’t mitigate, then we’ll need more adaptation. And that means that climate change is going to become more severe than it has been so far in the 21st century.

Susan Hassler: And that means more adaptation, both in urban and rural locations. Schnoor says we’ve already set climate change into motion. The signs are all around us.

Jerry Schnoor: Just while we’ve been doing this interview, we lost our power here, and we have severe weather forecast again today. Yesterday there were tornadoes also.

Susan Hassler: Now Schnoor’s using all the data he can to prepare his community accordingly. Are people ready for the changes that will be talking place because of new weather patterns? What do they think about increasingly severe weather? We took a microphone out to the streets.

Voices of people on the street:
“I definitely believe it’s related to climate change. That the more we mess with the environment, the more problems we’re gonna have with storms like this.”

“That’s the scary thing, with storms there’s really not much we can do except for, with global warming, try to slow it down as much as we can. But it seems kind of out of our control at this point.”

“Well, I think the effects of climate change is really affected by that, or that’s going to affect the size of the superstorms that we have. Growing up I don’t remember having superstorms.”

“I’m not totally informed, obviously, but I think it’s because of global warming, and you know the climate’s obviously changing, and it’s impacted by what we do.”

“Give us a heads-up. When the storm is really starting to develop a little bit, give us a heads-up. You got everybody running out here, trying to grab up all the water and everything, panicking, you know.”

“I guess a little personal responsibility is all you can do, because you can’t control the giant major awful things that are gonna happen.”

Rick Karr: We’re back with more “Adapting to Climate Change” in a moment. Stay tuned.

Susan Hassler: We’re back with “Adapting to Climate Change.” I’m Susan Hassler.

Rick Karr: And I’m Rick Karr. We started our program here in the U.S., where both coastal and inland communities are figuring out how to grapple with changing climate patterns.

Susan Hassler: And the U.S. is not alone. These kinds of efforts are happening all over the world.

Rick Karr: Take northeastern Brazil—a semi-arid expanse dotted with cacti and shrubs. Don Nelson has worked with farmers and families there for the last 15 years. He’s an anthropologist at the University of Georgia, and he says that even during the best of times, it’s a challenge to coax sustenance from the earth there.

Don Nelson: The people that we talk to have a very difficult life. Farmers age early here. Most of the agriculture is done by hoe. They’re entirely dependent on rainfall, but they take a lot of pride in the sorts of challenges that they have to deal with and that they have to overcome.

Rick Karr: Let’s focus on a particular 2500-acre farm. Less than 500 miles from the equator sits Fazenda Tamanduá.

Amilcare Porporato: Fazenda Tamanduá produces organic vegetables and fruits, for example, watermelons and mangoes.

Rick Karr: That’s Amilcare Porporato, a civil engineer at Duke University. He says the business model for this farm is pretty simple. To make a profit, it just has to sell those melons and mangoes when they ripen. Which happens to be the same time of year that demand is highest.
Amilcare Porporato: The market is ready to buy them only during a few months. And if they cannot produce the vegetables and fruits at the right time, they cannot sell them.

Susan Hassler: That’s because there’s very little demand off-season. So, everything’s fine for Fazenda Tamanduá until the crops appear on the market when peopledon’t want them, which is what’s happening now—because rainfall has gotten unpredictable. Up until recently, rain fell in northeastern Brazil seasonally. In other words, there was…

Amilcare Porporato: …a distinct sequence of wet and dry seasons.

Susan Hassler: The wet season tended to last a few months; about 2.5 feet of rain would fall within those months, and then the rest of the year was dry.

Rick Karr: Agriculture in this region relied on these predictable seasons, but now that rainfall pattern has changed and become highly variable.

Amilcare Porporato: Meaning that the wet season has become more uncertain: sometimes more wet, sometimes less wet. But it’s also become much more uncertain in the duration.

Susan Hassler: And uncertainty in the timing and amount of rainfall has huge consequences for agriculture.

Amilcare Porporato: So they cannot produce the watermelons and mangoes at the right time, and they cannot sell them. So it’s a very intricate and complex problem. It’s not just quantity of rainfall. It’s also timing.

Rick Karr: The impacts of these changing rainfall patterns can be severe. Take what happened last year in all of northeastern Brazil, something called a seca verde.

Amilcare Porporato: It means “green drought,” which basically, you have a wet season that brings you some rain, enough to make things green, but not enough really to provide enough water for the dry season that is going to follow. And so this had huge consequences. There were animals dying, cattle dying, crops wilting.

Susan Hassler: Don Nelson recalls seeing one farming community that got two-thirds of an inch of rain the entire year.

Don Nelson: Not even the weeds were growing in these fields. So you’re seeing really significant dry extremes, things that people haven’t seen here for many decades.

Rick Karr: A few different groups have stepped forward to help deal with this uncertain future. The first group: the farmers themselves.

Amilcare Porporato: The rainfall that comes in the wet season is stored traditionally in dams, or it infiltrates into the groundwater, and then it is used in the dry season for irrigation.

Susan Hassler: And so some of the consortia of farms are already building bigger dams in northeast Brazil.

Don Nelson: Sometimes they will plant only a part of their land with the first rains and wait for more rains to plant another part as a way to spread out some of the risk through time. They will sometimes plant in different areas, so you might have one area that’s very high and sandy that doesn’t hold water very well. And you plant in another low area that has more clay soil that tends to hold water as a way, again, to balance out some of this risk. People invariably are replanting their fields as well, so even if they plant the entire thing, they might hold back some seed knowing that there’s going to be loss.

Amilcare Porporato: Another thing that, of course, farmers are trying to do is to diversify their crops and planting more drought-tolerant crops. Of course, this is not easy when the drought is really at very high levels and very dramatic.

Rick Karr: A second group working on solutions is the government. It’s offering subsidies to farmers.

Amilcare Porporato: This is definitely something that is important, to keep the farmers where they are.

Susan Hassler: But at the same time, these subsidies are a very delicate business because they should really try to promote more sustainable agriculture instead of just providing means to cope with a year of drought.

Don Nelson: Yeah, I mean, there’s one family that really stands out that I visited. And they have been able to take advantage of different government programs that would give loans for particular types of investments, so that they were able to invest in technology; they were able to invest in training.

Rick Karr: The final group consists of people like Amilcare Porporato— engineers who are trying to help the farmers and the government plan their best strategy to deal with unpredictable rainfall by predicting the future.

Amilcare Porporato: Yes, yes, let’s say the next 10 years, the next 20 years.

Rick Karr: But, as you might guess, predicting the future isn’t easy.

Amilcare Porporato: Basically, our goal is to optimize irrigation in the long term. And the first challenge we have here is the fact that we cannot predict rainfall with actually any precision in the next years or decades.

Susan Hassler: Porporato wants to predict the future, but he doesn’t know when it’s going to rain, or how much rain will fall. It’s not like short-term predictions that rely on the forecast over the next few days to inform whether a farmer should water the fields or not. So how does Porporato do it? He actually builds that uncertainty right into his models.

Amilcare Porporato: The first step is to treat rainfall as a random function, something that contains these unpredictable components. Then this input of rainfall with its uncertainties propagated to see how plants would grow.

Susan Hassler: But Porporato’s predictions don’t just consider what crops need in terms of rainwater. He’s also taking the whole ecosystem of the farm into account.

Rick Karr: Porporato considers how irrigation changes the nutrient content in the soil. If you irrigate too much, you may have losses of nitrogen and nutrients into groundwater and into the streams. You may have risk of soil salinization if you don’t irrigate properly.

Amilcare Porporato: We, of course, have to maximize yields and profits because that’s why agriculture is done, but at the same time, we cannot sacrifice biodiversity. We cannot completely compromise the state and the health of the soil.

Rick Karr: So that’s what goes into formulating the predictions. And as for what comes out the other end?

Amilcare Porporato: Well, we can definitely help quantify how profitable or sustainable some type of crops would be compared to others. We can also provide indications of what are the best irrigation methods for long-term water-saving.

Susan Hassler: Porporato intends for his work to be used by farmers and policymakers alike, to plan which kind of irrigation strategy is best for the crops and the ecosystem as a whole, and to determine whether existing water reservoirs need to be expanded. Ultimately, Porporato hopes that his work can improve the lives of those who depend on the rain for their livelihood, like the farmers of Fazenda Tamanduá.

Rick Karr: But some of those farmers have started to see things differently. They recognize that their way of life, which has always been hard, may simply be impossible to sustain in the future. Don Nelson…

Don Nelson: People are really interested in kids getting out of agriculture, kids getting education, learning trade. And I think the small-scale family agriculture for a lot of people is no longer viable. It’s too risky, and too hard to maintain over the long run.

Susan Hassler: And so climate adaptation on the farms in this pocket of Brazil may crystallize around a new professional reality, one in which there’s much less farming and people take hold of their future by abandoning their past.

Rick Karr: We’re going to widen our lens one last time, to take the entire earth into our view. So imagine yourself hanging suspended in space, where you can see the effects of climate change swirling across our planet. Flash floods. Droughts. Sea-level rise. Superstorms. Heat waves. Are there things that people the world over are doing to respond to these changes? To answer that question, we need a guide.

JoAnn Carmin: My name is JoAnn Carmin, and I’m a professor in the Department of Urban Studies and Planning at MIT.

Susan Hassler: Carmin recently wrapped up a three-year project that had her shuttling all over the world.

JoAnn Carmin: I was in South Africa, Namibia, Philippines, Japan, England, and Ecuador.

Susan Hassler: In each of those countries, Carmin spoke with the people leading the charge on adaptation—government officials, business leaders, NGOs, and community groups.

JoAnn Carmin: There were many people I met who I found to be incredibly inspirational. Less like, oh, they figured it out. It was more that they were very reflective about trying to figure it out. They recognized that it was a process that was just starting, and they were very open-minded and thoughtful about how they were going forward.

Rick Karr: We spoke with two of the people who JoAnn Carmin says are doing the heavy lifting of developing climate adaptation plans in their cities.

Carl Spector: Carl Spector, Boston, Massachusetts.

Debra Roberts: Debra Roberts, Durban, South Africa.

Rick Karr: We’re going to highlight what each of these folks is doing in their cities and how they play into JoAnn Carmin’s findings. So let’s start with Debra Roberts, who heads up the Environmental Planning and Climate Protection Department in the city of Durban, South Africa, and its surrounding towns. She says that climate change is a big issue in Africa.

Debra Roberts: Anyone who lives in Africa is going to be worried about climate change. Southern Africa is really warming at twice the rate of the rest of the world. So we are probably the most vulnerable continent to climate change for a whole range of reasons: the positioning of our continent, underdevelopment, the huge levels of inequity, also our very fragile and endangered ecosystem.

Susan Hassler: Durban, South Africa, is a coastal city, which means that sea-level rise and storm surges are of particular concern. And it’s the poorest metropolitan area in the entire country, which makes things all the more precarious for the people living there. And yet, for a while, the threats posed by climate change were largely ignored in Durban.

Debra Roberts: We had really considered climate change to be a threat which was fairly low down on our agenda simply because we had so many other threats that we’re trying to deal with that are much more immediate and much more dangerous: poverty, unemployment.

Susan Hassler: Then, in 2004, on a sabbatical in the U.S., Roberts’s perspective changed. She came to see how climate change could undermine her country’s entire development path. And so when she returned to Durban, she and her team began to put together a climate protection program. JoAnn Carmin explains the process they went through.

JoAnn Carmin: Durban, South Africa, started out with a strategic plan. It was really a dedicated plan focused on adaptation. It covered the big vision. It talked a bit about the risks and then got into some of the actions that could be pursued.

Rick Karr: Since that time, they’ve now developed specific plans for particular sectors.

JoAnn Carmin: They’ve completed three sectors right now: water, health, and disaster. And here what they’ve done is, the departments themselves have worked through what are their priorities for adaptation.

Susan Hassler: Let’s spin the globe now, to Boston, Massachusetts, where Carl Spector is the city’s director of climate and environmental planning. He says rising sea levels is not an abstract problem there.

Carl Spector: Projected sea-level rise in Boston would lead to flooding of major areas around the seaport, around downtown. In other words, all of the land that Boston has created in the past several hundred years for the growth of the city. Those are the areas that are most vulnerable to sea-level rise.

Rick Karr: Boston was among the first cities to sign the U.S. Conference of Mayors Climate Protection Agreement. And one of Boston’s early climate plans contained ideas for both climate mitigation and adaptation. This sort of leadership, says JoAnn Carmin, is crucial.

JoAnn Carmin: Where there’s strong leadership, programs move forward much more seamlessly. Where there’s limited or weaker leadership—and in this case I’m talking about from among elected officials—it doesn’t move as smoothly or as easily.

Susan Hassler: In 2010, Mayor Menino received a set of recommendations from a climate action committee—a citywide task force charged with developing a plan to deal with climate adaptation in Boston. Those recommendations came in three flavors.

Carl Spector: The first one was that climate adaptation should receive equal priority to climate mitigation. The second major category of recommendations: We need to start taking action now. And the third point was that we needed to integrate climate adaptation into everything that the city does. And this has been the major approach that we’ve taken over the past few years.

Rick Karr: For instance, recently the Boston Water and Sewer Commission had to integrate climate-adaptation activities into their 25-year plan for dealing with storm water and wastewater. JoAnn Carmin says that she found this approach to be fairly common when cities work to build commitment around climate adaptation.

JoAnn Carmin: One way they build commitment is by taking something that on the face of it, and especially several years ago, was very unfamiliar, really unknown to many people, and helping the employees in cities and city departments understand why it was familiar, why it was nothing new. And then, from there, also saying, now, how does this connect to the ongoing work of each department? What does it mean if you’re the water department? And I think that begins to make this essentially more normal.

Susan Hassler: Carmin says that one lesson we can learn from places like Durban and Boston is that there’s no one right way.

JoAnn Carmin: Cities vary. Their needs vary, their goals vary, their resources vary, and therefore the approach they take has to vary. And I think that it’s easy to lose sight of that because even within cities, there’s that desire to find what’s right and find what’s best, and then pursue that process.

Susan Hassler: Carmin says that cities need to be true to themselves.

Rick Karr: That’s easier said than done, since it’s hard to program and plan for something as unpredictable as climate change. Here’s Debra Roberts again.

Debra Roberts: Of course, adaptation is a bit like playing Russian roulette. You don’t know what future you’re actually playing to because that future is a composite of so many changes in natural systems about which we have incomplete knowledge.

Rick Karr: JoAnn Carmin says that this uncertainty can provide the perfect context for cities to experiment and innovate as they figure out a plan for climate adaptation.

JoAnn Carmin: Frankly, from a planning point of view, we’re always dealing with uncertainty. The cities that are really at the forefront are those that are engaged in trial and error. They’re testing out how to plan. And if it doesn’t work, they’re okay with that. They’re able to say, “All right, here’s what we learned from this.” And so here what we see is more and more of these early cities saying, “Yes, we get it.” It’s uncertain, but that doesn’t mean we should be immobilized.

Susan Hassler: As more and more people feel the effects of climate change, more and more cities are in need of developing adaptation strategies, of planning for an uncertain future. JoAnn Carmin sees it as the perfect time to try things out, to see what works, and to develop local solutions for a change as big as the earth itself.

While governments are planning for worst-case scenarios, what do the people think about what’s being done? Back to the streets for some more answers.
Voices of people on the streets:
“I don’t know. I mean, you can’t keep building where there are storms. I mean, no matter what, you’re gonna have storms. And if you build where there’s a storm, it’s gonna happen again.”

“We have to humble ourselves before Mother Nature instead of thinking in terms of ‘Well, it’s your fault that the storm did this and the storm did that.’ We have to think nature first.”
“Since obviously we can’t control the weather, I guess the only thing we can do is be a little bit more personally prepared for it.”

“There’s definitely need to be…study the problem more and see what we need to do as far as whether it be curbing our carbon emissions or being prepared a little bit better. I don’t know. I don’t know the answer to that, but I hope we figure it out soon!”

Rick Karr: You’ve been listening to “Adapting to Climate Change,” a coproduction of IEEE Spectrum and the Directorate for Engineering of the National Science Foundation.

Susan Hassler: The directorate supports people whose discoveries and inventions make our lives more productive, sustainable, and enjoyable.

Rick Karr: For transcripts of this program, and expanded stories, check out the IEEE Spectrum website: You’ll also find many other engineering features at this website for the National Science Foundation:

Susan Hassler: We had support for this program from the Alfred P. Sloan Foundation—enhancing public understanding of science, technology, and economic performance. More information on Sloan at

Rick Karr: Our thanks to the staff and editors at IEEE Spectrum, and to John Barth, Prachi Patel, Ari Daniel Shapiro, Mia Lobel, and Paul Ruest at the Argot Studios. Our technical producer is Dennis Foley. Our executive producer is Sharon Basco. I’m Rick Karr.

Susan Hassler: I’m Susan Hassler. This IEEE Spectrum production is presented by PRX, the Public Radio Exchange. Thanks for listening.

Anchors: Susan Hassler and Rick Karr

Technical producer: Dennis Foley

Executive producer: Sharon Basco

Photo: Charles Sykes/AP Photo