DAVE DAVIES, HOST:

This is FRESH AIR. I'm Dave Davies, in today for Terry Gross.

Our guest, New Yorker staff writer Elizabeth Kolbert has a new book which deals, as much of her writing does, with the enormous impact we humans have on the planet we inhabit and the species we share with it. We've dammed or diverted most of the rivers on Earth, she writes. We now routinely cause earthquakes. And today, people on Earth outweigh wild mammals by a ratio of more than 8 to 1. Her last book, "The Sixth Extinction," which won the Pulitzer Prize for nonfiction, explored the many ways humans are now driving existing species to extinction.

Her new book, she says, is about people trying to solve problems created by people trying to solve problems. She profiles specific efforts to undo damage to the natural world caused by human efforts to rid a pest or secure our water supplies or fuel our cars and factories. The stories range from a campaign to rid Australia of enormous toxic toads, originally introduced to eat beetle grubs in sugar cane fields, to plans to try and cool our warming planet by sending millions of tiny particles into the stratosphere. That might absorb some of the sun's energy and lower temperatures, but it could also give once-blue skies a paler, bleached hue.

Elizabeth Kolbert's book is "Under A White Sky: The Nature Of The Future." She joins me from her home in Williamstown, Mass.

Well, Elizabeth Kolbert, welcome back to FRESH AIR.

ELIZABETH KOLBERT: Thanks for having me, Dave.

DAVIES: Before we talk about the book, I want to turn to current events for just a moment. You wrote in a piece in September that it is no exaggeration to say that what the next president does or doesn't do on climate change will affect the world for millennia to come. You then list a number of steps that he needs to take dealing with regulations the Trump administration has imposed and, you know, new ones he might enact. It's early, but what do you see, and how is he doing?

KOLBERT: Well, I think that the Biden administration gets very high grades on climate change so far. The president said he was going to do certain things on Day 1, and he actually did that - for example, rejoining the Paris Accord, which was the global, you know, treaty designed to get the world to focus on doing something about climate change, which the Trump administration had withdrawn the U.S. from, and that was a terrible blow to the process. Now - and he's signed a slew of executive orders, many of them designed simply to, you know, overturn Trump-era executive orders, but also some that were designed to go further than that. The Trump administration left them with a lot to undo. That's going to take quite a long time, unfortunately. But they've come out of the box quite strong, I think.

DAVIES: So just give us a few of the details. What do some of these executive orders deal with?

KOLBERT: Well, to give one example, one of the executive orders that he signed - he signed a sort of big, massive climate change executive order last week that had many components, and one of those components was to use the federal government's procurement powers. So the federal government, you know, buys just a lot, a lot of stuff to try to foster the transition to a clean energy economy. So, for example, having the federal government buy electric vehicles to become part of that process of sort of using that technology and getting it out there and supporting it. So that's just one example.

There are - he created a new Office of Domestic Climate Policy to try to coordinate climate policy because you really need to make a fundamental difference. You need all of the federal government's policies sort of pointed in the right direction. You can't have contradictory policies. And I think they really understand that.

DAVIES: And he's going to spend nearly $2 million (ph) on a stimulus plan and COVID relief package and then hopefully after that, he says, a very big infrastructure program and, you know, clean energy program. So there's potential for a lot there, I guess.

KOLBERT: Yes. I mean, I think, you know, to add a caveat, we're very early in this administration and we - in the best of all worlds, we would see major climate legislation. Whether that is possible with such a slimly divided Senate, you know, remains to be seen.

DAVIES: Are there any legal obstacles to reversing some of the steps that the Trump administration took?

KOLBERT: Well, there are - in some cases, there are complexities. In general, what you need to do is rewrite and repromulgate these regulations. It's a time-consuming process, and there's a, you know, big record that has to be created to justify those regulations. And in many cases, the Trump administration didn't provide a very good record, and that's sort of a boon for the Biden administration. But one big question that also stands out there is a lot of the new regulations - everyone knows they're going to be litigated. They're going to go to a Supreme Court that's, you know, sort of divided 6 to 3 now and has a pretty anti-regulatory strain to it. And so one real challenge for the administration will be crafting regulations that they think can go to the Supreme Court and withstand that.

DAVIES: All right, we will see. I'm sure you'll stay on top of it. Let's talk about your book, "Under A White Sky." You tell a really fascinating story about unintended consequences of our intervention in nature, arising from, really, a remarkable feat in human engineering involving the Chicago River. I mean, this happened decades ago, but tell us about this.

KOLBERT: Sure. So Chicago grew up along the Chicago River, which, you know, for millennia flowed east through what's now Chicago and into Lake Michigan. And as Chicago grew up around on the banks of the river, it dumped all its waste into the river - so all of its human waste and all of the waste from the stockyards that grew up, the enormous stockyards, that grew up in the city. And it was said that the river was so thick with filth that a chicken could walk across it without ever getting her feet wet. And this was, you know, a problem not just because it was disgusting, but because Lake Michigan was and it still remains Chicago's sole source of drinking water. So there's a lot of waterborne disease.

So around the turn of the 20th century, it was decided something really had to be done about this, and this something was to dig an enormous canal. It was one of the biggest construction projects of its day - dig an enormous canal that would connect the river to the - basically, to the Mississippi drainage basin. And instead of flowing east into Lake Michigan, the river would now flow towards the Mississippi. And so ultimately, Chicago's waste now drains all the way into the Gulf of Mexico.

DAVIES: So this is actually (laughter) reversing the flow of a river. It actually - this is a measure of what humans can do. There was sort of a lock put in it where it joined Lake Michigan, and then it just took a hard right turn and now goes west and leads into rivers that drain into the Mississippi. I mean, sewage treatment - it's better. It's not raw sewage coming into there anymore. But there's a lot of stuff. And you describe taking a trip down this redirected river, which is now called the Chicago Sanitary and Ship Canal. And you did this with a group called Friends of the Chicago River. And at some point, you're going down there, and you see these signs that say entering electric fish barriers - high risk of electric shock. Why was this river electrified? (Laughter).

KOLBERT: Well, one of the unintended consequences of reversing the Chicago River was to draw a connection, to create a connection, through this canal that was dug for the purposes of reversing the river. The canal connected these two enormous drainage basins - the Mississippi River drainage basin and the Great Lakes drainage basin - that had previously been separate. So if I was - if I were an aquatic creature, I could not move from one to the other. Suddenly, there was this connection. And over the course of the 20th century, both the Great Lakes and the Mississippi River system became highly invaded waterway systems. They are both filled with invasive species, some of them introduced purposefully, most of them not. And they are wreaking havoc in both systems. And now it was possible for them to move from one to the other. And so it was decided something needed to be done about that. We'd reverse the river.

Now we needed to lay over that another layer of intervention to keep these species from moving from one basin to the other. And the solution that the U.S. Army Corps of Engineers came up with - I call it a solution, I guess, somewhat in quotes - was to electrify a portion of the sanitary and ship canal. So the friends of the Chicago River took me down the canal quite a number of miles from Chicago. You hit these enormous signs where the river is literally electrified. And were you to make the error of, you know, going for a swim, you would, quite possibly, end up dead.

DAVIES: Wow. Do the electric shocks in the water kill the fish or warn them first?

KOLBERT: Well, the idea is that they will experience a shock. Yes. And they will turn around. That's the idea. And I think, in general, that's probably true. I should - I will mention, though, as we went through these barriers, there were all sorts of birds that had gathered who knew that they were going to get an easy dinner right there. So I'm not sure exactly what's going on underwater. But the idea is that the animals will be dissuaded from crossing that section of the canal. It's actually a fairly long stretch that's electrified.

DAVIES: We need to take a break here. Let me reintroduce you. We're speaking with Elizabeth Kolbert. She's a staff writer for The New Yorker. Her new book is "Under A White Sky: The Nature Of The Future." She'll be back to talk more after this short break. This is FRESH AIR.

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DAVIES: This is FRESH AIR. And we're speaking with New Yorker staff writer Elizabeth Kolbert. Her new book, "Under A White Sky: The Nature Of The Future," profiles cases where people are trying to reverse damage already done by humans to the natural world.

OK. So now we have this canal that goes down from Chicago. And it connects to the Mississippi River Basin. And one of the invasive species that they were concerned about making its way up from the Mississippi Basin through that canal into Lake Michigan is the Asian carp. And you tell us in the book there are actually four different species of this fish. Why were they introduced into the United States in the first place?

KOLBERT: Well, that's a really interesting tale, it turns out. There are, as you say, four species of Asian carp. And they are often raised together in very sophisticated aquaculture operations. They were brought to the U.S., though, not for that purpose. The first species is grass carp. They were brought to the U.S. as an attempt at biocontrol of invasive aquatic weeds. So they were supposed to eat this vegetation. And this was in the '60s. And it was, interestingly enough, in the wake of "Silent Spring," Rachel Carson's blockbuster book "Silent Spring," which warned Americans about the perils of pesticides and herbicides, which were sort of indiscriminately being used on our fields and in our waterways.

And so there was a real effort at that moment to turn away from chemical solutions to a lot of these problems. For example, invasive weeds to biocontrol. She explicitly recommends, at the end of "Silent Spring," using one species against another, basically. So grass carp were brought in for that reason. They quickly escaped where they were supposed to be and were everywhere. The others - some other species, silver carp and bighead carp, were brought in because they eat algae. And the idea here was they were going to help relieve some of the nutrient loading from sewage plants. They immediately escaped and were everywhere.

DAVIES: Wow. So what problems do these carp present now that they are out and growing and moving up the Mississippi River Basin to its various tributaries?

KOLBERT: Well, they present a bunch of problems, one of which they're simply extremely successful. Now, you could say that's not really, you know, it's not really a problem for them. But it's obviously a problem for species they're competing with. So all sorts of, you know, fisheries, fish, native fish that used to be fished along the Mississippi and its tributaries have plunged in number because Asian carp are just outcompeting them. They're very voracious filter feeders. Silver carp and bighead carp, they sort of filter everything out of the water column. So that's one very serious issue. Another serious issue (laughter) is that silver carp have this interesting habit. When they're startled in any way, they fling themselves up out of the water. They jump. And they're fantastic jumpers. On sort of carp-rich stretches of the Illinois River, let's say, if you go boating or water skiing, your odds of being hit by an Asian carp, which is by a silver carp, which has been, you know, startled by the noise of your own motor, are quite high. So they actually present, you know, a physical danger.

DAVIES: And in the course of your research, you got slapped once, right?

KOLBERT: Yes. They just - I was out on a boat. One of the - in addition to trying to keep the fish out of the Great Lakes by electrifying the river - and I should also add, there are plans for new barriers that are supposed to use noise and bubbles. It was a joke to me that it was sort of a disco...

DAVIES: (Laughter).

KOLBERT: ...Barrier, which there are very serious plans on the table. The Army Corps of Engineers is looking for funding for these. Another method that's used to try to keep the fish from, actually, you know, nudging up against the barriers - they call it barrier defense - is just a lot of Asian carp are hauled out of various waterways and simply killed.

DAVIES: By fishermen, right? By fisherpersons, right? Yeah.

KOLBERT: Fishermen, I think, because they all were men the day I went out, who are paid, basically, to take Asian carp out of the waterways. And then they're, in the cases that - where I went out fishing with them, they were usually being put into a big container and shipped out west and ground into fertilizer. And then, when they caught a native fish, they'd throw it back.

DAVIES: This idea that began as a way of a bio solution to a problem of nuisance grasses, et cetera, ends up with the government paying, you know, fishermen to manually haul these things out of here. And that's - how much do these contractors make? Who pays them?

KOLBERT: Well, in this case, they were being paid by the state of Illinois. You know, they can make, I think, a pretty good living. As I say in the book, I think, you know, you can gross up to upwards of $5,000 a week. Now, you do have a lot of expenses associated with it as well. So I don't know exactly what you're netting - how's that? But people who used to fish for native fish and that was their living - and now there are no native fish - can make a living contracting with the state, becoming contract fishermen for the state of Illinois.

DAVIES: Which are hauled away and ground into fertilizer.

KOLBERT: Exactly.

DAVIES: You know, another idea of dealing with this is - since, you know, we as humans, certainly, know how to suppress fish populations by overfishing, another idea is to get people interested in eating carp. How's that (laughter) going?

KOLBERT: Well, I want to say that I - in my adventures, you know, in Illinois, I did end up eating a fair amount of Asian carp that people had prepared in different ways as part of this effort, as you say, to get humans to act, as it were, as a biocontrol agent, because as one of the biologists in Illinois, you know, put it to me, we know that humans can overfish. We know that humans can drive fish populations to zero, you know?

So if you want to control a fish population, the best thing to do - the worst thing to do for the fish, the best thing to do, you know, for the - for overfishing is to get humans interested in eating something. And so people have worked on all sorts of killer dishes, as it were. And some of them were quite tasty. So far, though, the problem with Asian carp as a sort of commercial species is - and this is true across the species, is that they have - they're very bony. And Americans tend to like their fish boneless. So that's been a real challenge.

DAVIES: Right. So you got to grind it up into, you know, like, cakes, I guess.

KOLBERT: Into something.

DAVIES: Right. Right. And how was your carp cake?

KOLBERT: Very tasty. I completely recommend it. Yeah.

DAVIES: You talked to a lot of people who've been involved in this, from the Army Corps of Engineers to local folks. And I'm wondering, people must have some kind of perspective on this whole process, you know, introducing a different species to benignly deal with another problem and then having it grow out of control and then trying all of these methods. I don't know. What kind of perspectives did you get here? What lessons did people draw?

KOLBERT: Well, I think the lesson that they drew from it was, you know, we ought to be a lot more careful (laughter). How's that? When you are dealing with very complicated biological systems, you can intervene in ways that will have unintended consequences. That's a very, very common theme of efforts at biocontrol. But once a species is established - that's sort of the technical term in invasive species biology - it's very, very, very hard to reverse the clock.

DAVIES: Looking at the macro trends, are government agencies now more careful about bringing in species to solve a biological problem?

KOLBERT: They would certainly, say that. And I would certainly give them credit for that. There are many, many - if you're going to bring in - introduce a species purposefully, I should say - there are a gazillion species being introduced all the time, you know, just in the ballast water, let's say, of supertankers. That's the way many of our aquatic invasive species arrive. No one knows they're there, you know? They might even be microscopic.

But if you're going to purposefully introduce something into a landscape, there are tremendous permitting issues that you have to go through. And you have to go through a lot of testing. But I do think that, you know, even under the best of circumstances, you're only finding what you're testing for. And so you can't always anticipate, even now, after a lot of testing, exactly what impact that introduced species is going to have. But, yes, definitely, people have learned a certain lesson from these bitter experiences.

DAVIES: We need to take a break here again. Let me reintroduce you. We're speaking with Elizabeth Kolbert. She's the staff writer for The New Yorker. Her new book is Under "A White Sky: The Nature Of The Future." We'll continue our conversation after this short break. I'm Dave Davies. And this is FRESH AIR.

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DAVIES: This is FRESH AIR. I'm Dave Davies, in for Terry Gross. We're speaking with New Yorker staff writer Elizabeth Kolbert. She won a Pulitzer Prize for her last book, "The Sixth Extinction," about the many species humans are driving to extinction. Her new book profiles cases where people are trying to reverse damage already done by humans to the natural world, from efforts to get rid of a toxic toad, originally introduced as a predator to save crops, to engineering projects on an enormous scale to try and slow or reverse global warming. Her book is "Under A White Sky: The Nature Of The Future."

So you write about some efforts that are intended to deal with global warming, which is obviously the biggest way in which we humans have affected the natural world - or arguably the biggest way. You begin by talking about a personal experience. You responded to a pitch from a company called Climeworks, where, for a price, they would scrub your carbon emissions from the air, or at least emissions like yours. You subscribed. You went and visited their facility. What do they do?

KOLBERT: What Climeworks does, it's a process that's become known as direct air capture. And they're a Swiss company. And I went to visit a project they have in Iceland. And what this device looks like is a giant air conditioner. And it's running air through this machine. And inside the machine is a chemical that binds with carbon dioxide. So just the ambient air is going through the machine. The carbon dioxide is sort of sucked out and absorbed by this material. And then the material, the chemical gets heated up. And the carbon dioxide is driven off and collected in a sort of bladder-like thing. And then the process starts all over. So it cycles over and over, and over again. And that's how my - you know, quote, unquote, "my emissions" were being scrubbed from the air.

DAVIES: All right. So we take the carbon dioxide out of the air. It ends up in the bladder-like thing. Then what happens to it?

KOLBERT: Well, at this facility - and this is what makes this particular facility, really, particularly interesting and particularly cutting-edge - it gets combined with a lot of hot water. And it then gets piped deep underground, about a half-mile underground. And down there in this volcanic rock that is Iceland - Iceland is just, basically, made up of volcanic rock - it's hot. And there's a lot of, you know, water involved. The carbon dioxide combines, reacts with this volcanic rock to form calcium carbonate. And it basically gets mineralized.

And the scientist I was with - I visited it with an Icelandic scientist by the name of Edda Aradottir. I hope I'm pronouncing that correctly. She had brought along a core. It wasn't, you know - it hadn't been drilled - for me, it had been drilled, you know, for scientific purposes. But they had gone a kilometer underground to see - try to see, you know, what was really happening. And you could see in this volcanic rock, which has a lot of openings in it, sort of porous rock, you could see the calcium carbonate that had formed. And that was, you know, someone's carbon emissions that had been mineralized.

DAVIES: Wonderful. So you can pull carbon dioxide out of the air and turn it into a rock. Sounds great. This concept is called negative emissions, right? In that it is - rather than adding more carbon dioxide into the air, it is actually extracting some of the carbon dioxide we've already emitted. So that's the idea. This happens at the place you visited on a pretty small scale. Give us a sense of the scale of extracting carbon dioxide you'd have to accomplish to make a meaningful dent in climate change.

KOLBERT: One thing that's important, too, to recognize - you know, there's a lot of talk now. You will hear - I'm sure your listeners have heard this phrase net zero. We need to get to net zero in carbon emissions. And there are some things that are - some activities that are really, really hard to get to zero. So the idea would be, well, OK, we won't get all the way to zero. Then we'll have to use these negative emissions. We'll have to try to balance out things that we can't get rid of with these negative emissions. Now, that sounds great. And it, you know, makes a lot of sense in a lot of ways. But the scale of our emissions is such - we are now emitting roughly 40 billion metric tons of CO2 every year by burning fossil fuels.

To bring that down, you know, requires massive investment in new infrastructure. That sort of gets back to what we were talking about at the top of the show. Hopefully, we will be seeing some of those massive investments. But the scale of negative emissions that a lot of these scenarios that are used by groups like the Intergovernmental Panel on Climate Change to project, you know, how we could potentially stay under certain temperature targets, they're huge. They are, you know, in the billions of tons a year. And as you point out, you know, this one little machine that was operating in Iceland, they're actually expanding that operation, too, I should add. But we're still talking about, you know, maybe they're capable of dealing with, you know, tens or hundreds of tons. And we need to scale up to billions of tons.

DAVIES: You spoke to a physicist named Carl - Klaus Lackner, one of these visionaries who believe in this and think we're going to have to get there sooner or later. He has this idea of - well, you can describe it - kind of a machine that kind of looks like a folding couch that you could expand into these sort of tractor-trailer sized units. You want to just describe this and how it will work?

KOLBERT: Yes. This prototype that I visited - they sort of just had a prototype at that point. It was a - there are many ways, you know, to skin the cat, as they say. And this one was particularly - Klaus Lackner is a professor at ASU in Tempe, Ariz. And so this was designed for a very dry climate where the carbon would be absorbed by this sort of beads that they had embedded in the slats of this sort of folding couch arrangement. And the idea was that, then, those - instead of using heat to drive off the CO2, you'd immerse them in water. Once this material hit the water, the CO2 would be released. Once again, you'd collect it. Once again, you have to do something with it. That becomes a major issue with carbon dioxide removal. What are you going to do with this stuff?

DAVIES: Even if you could get to a net zero carbon emissions, there is all this carbon dioxide that's up there now and would continue warming the planet, right? So you kind of need to fetch some of that, too, don't you?

KOLBERT: You know, if you really want to be futuristic about it, you could say, well, if you perfected this technology - now, one thing that I should also mention, which is crucial here, is it takes energy, right? All of these processes take energy. We get energy by burning fossil fuels. That's why we do it. And then to get the CO2 out of the air - this is sort of, you know, just a product of, you know, thermodynamics - it requires energy. And it's always going to require energy. And the hope is to get it down to as little energy as possible. But as long as you're getting your energy from burning fossil fuels, there's a limited return, you know, you can get.

But if you got to a point - and once again, in some theoretical future - where you're generating huge amounts of carbon-free energy and you have a lot of excess of it, and then you start using that to try to pull carbon out of the air - once again, this is a pretty futuristic scenario, but I will put it out there - theoretically, you could say, well, yeah, we want to decide - we could decide what the optimal CO2 in the atmosphere is. Humans could decide that.

DAVIES: Let me reintroduce you again. We are speaking with Elizabeth Kolbert. She's a staff writer from The New Yorker. Her new book is "Under A White Sky: The Nature Of The Future." We'll be back to talk more after this break. This is FRESH AIR.

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DAVIES: This is FRESH AIR. And we're speaking with New Yorker staff writer Elizabeth Kolbert. Her new book is "Under A White Sky: The Nature Of The Future."

There's another set of ideas to deal with global warming apart from removing carbon dioxide, which we put in the atmosphere. How does it happen? How do we do it?

KOLBERT: Well, this is, you know, the subject of a good deal of study. But the idea here - and it's often referred to as solar geoengineering or, you know, potentially a solar radiation management, a little bit more soothing way to put it - is that we would - I think, you know, sort of the general consensus, as it were, to the sense that there is a consensus is you'd need a fleet of specialized aircraft and they would - that were capable of carrying big payloads into the stratosphere because you have to get these reflective particles into the stratosphere. Otherwise, they will simply, you know, drop out too quickly. And then, on stratospheric sort of winds, they're sort of blown around the world. And you could create this, you know, artificial volcanoes basically by dumping a lot of sulfur dioxide into the stratosphere from aircraft.

DAVIES: So what kind of particles would be sprayed up there?

KOLBERT: While I was reporting the book, I spent a bunch of time with scientists at Harvard who run a thing called the Harvard Solar Geoengineering Research Program. And, you know, they were looking at - this is, you know, a research project to look at what the possibilities are and what the possible, you know, downsides are to say - to put it mildly. And they were looking at - you know, the compound that volcanos use, as it were, is sulfur dioxide. So that's one sort of obvious possibility.

But sulfur dioxide has a lot of problems, causes acid rain, could potentially contribute to the depletion of the ozone layer. So they were also looking at calcium carbonate, which is just basically limestone, you know, limestone dust. And one of the scientists mentioned to me, well, maybe a good particle to use would be tiny little ground up diamonds, you know, industrial diamonds, which struck me as a really interesting idea. Lucy in the sky - yeah.

DAVIES: Uh huh - and expensive. Well, so if this happened, if you got, say, you know, calcium carbonate, the limestone dust, and you got enough planes and you got enough stuff up there, what would we experience? What would it look, what would it feel like?

KOLBERT: There are, you know, many, many, many potential effects of, you know, putting up a reflective haze, you know, some of which we've seen obviously through volcanic eruptions. But one of the potential side effects of doing this on a massive scale is you would change the appearance of the sky. So if you went to a place that now you'd expect to see, you know, a bright blue sky on a sunny day, it would have more of a whitish tinge. And that's the source of the title for the book, "Under A White Sky."

DAVIES: Not a happy thought. I mean, another issue here, of course, is that when you spray all these particles up there, you're not dealing with the carbon dioxide in the atmosphere. I mean, maybe you are at the same time, but that itself doesn't affect it. And the particles do eventually fall to Earth. So you have to keep doing it, right?

KOLBERT: Well, one of the, you know - and once again, I mean, I think I quote a bunch of scientists who are, you know, very, very strongly opposed to this idea. And some - one of them calls it, you know, a broad highway to hell. And one of the problems - I mean, precisely the problem, precisely the reason why you would contemplate something like this is because once you put carbon dioxide into the atmosphere, it lasts a long time, and it continues to warm the earth for a long time. So it's very difficult to do something about climate change quickly. That's a very, I think, important point. And that is what is motivating this research.

If you reach a climate that you say, we don't like this climate, we need to do something quickly. It's not enough to cut emissions at that point. It's not enough to cut emissions to zero. That simply means that the problem isn't getting worse. It's not making the problem better. So if you get to a point where, you know, you say the world simply cannot, you know, support temperatures like this, you have very, very few options. And this is one of the very few options that people have come up with.

Now, it has tremendous, you know, perils associated with it, one of which is that you are committing future generations to continue to do this. Otherwise, if you were to suddenly stop, you would - all that warming that's essentially been counteracted or masked would presumably suddenly manifest itself. So you could get what's called - it already has a name - termination shock. And the question of, you know, whether that's ethical to bind, you know, future - you know, even if it were - even if you decide it was ethical for us to do it but to commit, basically for the foreseeable future, our children and our grandchildren have to do it, this raises all sorts of extremely vexing questions, to say the least.

DAVIES: So the judicious way to do it would be to, as part of - to buy some time while you aggressively try and deal with emissions and the existing carbon dioxide.

KOLBERT: That is the argument, and that is the argument for a lot of these interventions, which are, you know, interventions on top of interventions. They - the justification end would be - or the argument would be hopefully, you know, during the course of the 21st century, let's say, we will - humanity will be exerting its maximum impact on planet Earth. And if we could get through this moment with the minimum amount of damage, with the fewest extinctions, you know, we would have done something, you know - how about - I don't want to say positive. I'll say less awful than the alternatives.

DAVIES: You know, your book begins with a number of stories that involve human harm to other species - I mean, tiny fish in Nevada and the coral of the Great Barrier Reef and the other ones we've discussed. It's only at the end of the book that you take us to efforts to confront the threat to our own species from climate change. I figure this must have been a conscious choice, and I wonder why you chose to organize it that way.

KOLBERT: Well, the book is organized as a series, you know, of interventions. You know, this new chapter in our long and vexed history with the natural world where we are now, as it were, sort of chasing our own tail, where we're now intervening to counter the effects of our own intervention - I think I - you know, I sort of call it the control of the control of nature.

And the book starts out with examples of this where we're already doing it. You know, there are the electric fish barriers. You can go, you know, visit them. I also go visit a project in southern Louisiana which - where we're trying to counteract the land loss that southern Louisiana is experiencing because we've been so successful at controlling the flow of the Mississippi that now we're trying to impose a form of controlled flooding to counteract the negative effects of flood control, one of which is this tremendous land loss in the southern part of the state of Louisiana.

So these are projects that are either - you know, already exist or are very much going to happen. They're on the books. They're in the design phase. And then as we go through the book, we get to things that are much more sort of futuristic and speculative, as it were. And sort of - that's sort of what takes us at the end to the grandest example that's been proposed so far, at least, which is, you know, dimming the sun to make up for the effects of all the carbon dioxide that we've already poured into the air.

DAVIES: You've been writing about climate change for a long time. And most of us are aware of the harm of climate change, but we don't have to think about it every day, which is maybe one of the big problems. I will say that when I do think about it, I really wonder about the world my kids and grandkids are going to inherit, and it gets really scary. You spend a lot more time than most of us contemplating this. And I'm just wondering what this means to you at a personal level.

KOLBERT: Well, you know, I spend a lot of time being very scared (laughter). How's that? I mean, I have kids, too. And I am - you know, I think that's a very legitimate response - how's that? - to look into the future and be very worried.

DAVIES: Well, Elizabeth Kolbert, thank you so much for speaking with us.

KOLBERT: Oh, thanks for having me.

DAVIES: Elizabeth Kolbert is a staff writer for The New Yorker. Her new book is "Under A White Sky: The Nature Of The Future." Coming up, rock critic Ken Tucker explores the experience of heartbreak through new songs from three artists, including Jazmine Sullivan, who sang the national anthem at this year's Super Bowl. This is FRESH AIR.

(SOUNDBITE OF JERRY GRANELLI'S "THE GREAT PRETENDER") Transcript provided by NPR, Copyright NPR.