Mark: Alright, Michelle, I have a weird one for you. What if I told you that one of the most celebrated engineering marvels in American history—a project that saved a major city—also accidentally declared war on the Great Lakes? And the weapon of choice was a flying fish. Michelle: Hold on. A flying fish? That sounds like something out of a bad sci-fi movie. You’re telling me a brilliant piece of engineering led to an aquatic air force causing chaos? I don't buy it. Mark: It’s not only true, it’s the perfect entry point into the bizarre world of Elizabeth Kolbert’s book, Under a White Sky: The Nature of the Future. Kolbert is this incredible, Pulitzer Prize-winning journalist for The New Yorker, and she has a knack for finding these stories that are simultaneously brilliant, tragic, and darkly funny. Michelle: I’ve heard of her, she wrote The Sixth Extinction, right? The book that made everyone feel existentially terrified but in a very well-researched way. The book was widely acclaimed, but some readers found it pretty bleak. Does this one follow that trend? Mark: It does, but with a twist. Instead of just documenting what we're losing, this book is about the wild, often absurd things we’re doing to fix what we’ve already broken. She doesn't just report from a library; she goes to these strange, engineered landscapes to see the consequences firsthand. And it all starts with this story of a river that was forced to run backwards. Michelle: Okay, a backwards river and flying fish. You have my full attention. Where on earth does this story begin?

Mark: It begins in late 19th-century Chicago. The city was booming, a hub of industry and innovation. But it had a very disgusting, very deadly problem. All of its sewage and factory waste was being dumped directly into the Chicago River. Michelle: That sounds... unpleasant. Mark: Deeply. And the Chicago River flowed directly into Lake Michigan, which was the city’s only source of drinking water. So they were, quite literally, drinking their own filth. This led to horrific outbreaks of waterborne diseases like typhoid and cholera. Thousands were dying. Michelle: Wow. So it was a public health catastrophe. What was their solution? Better water filters? Mark: Oh, they thought much, much bigger. The city’s engineers came up with a plan so audacious it sounds like a myth. They decided to permanently reverse the flow of the Chicago River. Michelle: Wait, what? You can’t just... reverse a river. That’s like telling gravity to take a day off. How is that even possible? Mark: With an incredible amount of dynamite, steam shovels, and seven years of back-breaking labor. They dug the 28-mile-long Chicago Sanitary and Ship Canal, a massive channel that connected the Chicago River to the Des Plaines River, which eventually flows into the Mississippi. By doing this, they created a new downward slope, forcing the Chicago River to flow away from Lake Michigan, carrying all that sewage south towards the Gulf of Mexico. Michelle: That is absolutely bonkers. They re-plumbed an entire region just to get rid of their sewage. Did it work? Mark: It worked spectacularly. The water in Lake Michigan became clean again, and the disease outbreaks stopped. There's a famous newspaper headline from the time that perfectly captures the mood. After the reversal, The New York Times ran a story with the headline: "WATER IN CHICAGO RIVER NOW RESEMBLES LIQUID." Michelle: That’s the most backhanded compliment I’ve ever heard. It must have been truly foul before. So, problem solved. A triumph of human ingenuity. End of story? Mark: Not even close. This is where the law of unintended consequences, a central theme of Kolbert's book, kicks in with a vengeance. In their brilliance, the engineers had done something no one had considered. They had blasted a permanent, artificial connection between two of the continent's largest, and previously separate, aquatic ecosystems: the Great Lakes basin and the Mississippi River basin. Michelle: Uh oh. That sounds like opening a door you can’t close. It’s like connecting two different planets with a hallway. Mark: Exactly. And through that hallway, things started to move. Invasive species could now travel freely between these two massive water worlds. For decades, it was a slow trickle. But then, in the 1970s, another well-intentioned human "fix" came into play. Michelle: Let me guess. This is where the flying fish come in? Mark: This is where the flying fish come in. Following the environmental movement sparked by Rachel Carson's Silent Spring, people were looking for natural alternatives to chemical pesticides. So, fish farmers in the South, with government encouragement, imported several species of Asian carp to control algae blooms in their ponds. Michelle: A biological solution. What could go wrong? Mark: Well, carp are escape artists. Floods came, and the carp got out of the ponds and into the Mississippi River system. And it turns out, they are, as one expert in the book puts it, "very good at being invasive." They’re voracious eaters, they reproduce at an incredible rate, and they outcompete native fish for food. They’ve been steadily moving north up the river system, a slow-motion invasion heading directly for that man-made highway into the Great Lakes. Michelle: And these are the jumping ones? Mark: These are the jumping ones. The silver carp, one of the species, has a bizarre reaction to the vibration of boat motors. They leap out of the water, sometimes ten feet in the air. Kolbert describes waterskiing in parts of the Illinois River as an extreme sport. People get hit, knocked out of boats, break bones. A ten-pound fish hitting you in the head at 30 miles per hour is no joke. Michelle: So we have these projectile fish, an ecological disaster in the making, all because Chicago didn't want to drink its own sewage a hundred years ago. It's a perfect, cascading failure. What is the fix for the fix for the fix? Mark: This is where the story gets even more surreal. To stop the carp from reaching Lake Michigan, the Army Corps of Engineers has built a series of electric barriers in the canal. Michelle: You’re kidding. We are now electrocuting a river. Mark: We are electrocuting a river. It’s a series of steel electrodes on the bottom of the canal that pulse a powerful electric field into the water. The idea is that it will stun or repel any fish that try to swim through, without stopping the massive barges that still use the canal for shipping. It’s a billion-dollar, high-tech, last line of defense. Michelle: This is incredible. We’ve gone from reversing a river to zapping it with electricity, all to stop a fish we introduced on purpose to solve a different problem. Kolbert must have had a field day with this. Mark: It’s the perfect illustration of her core argument. We wield this immense power to reshape the world, but we rarely understand the full consequences. Our solutions create new, often more complex problems, which then require even more elaborate, expensive, and risky interventions. We’re trapped in a cycle of control.

Michelle: That idea of being trapped in a cycle of control is really powerful. It feels like we’re constantly patching a ship that we keep putting new holes in. Do we see this pattern elsewhere? Mark: Everywhere. And Kolbert takes us from that grand, industrial scale of the Chicago River to something much smaller, but somehow even more profound and strange. She takes us to the Mojave Desert, to a place called Devils Hole. Michelle: Devils Hole. Sounds inviting. Mark: It’s a limestone cavern, a crack in the earth that opens into a deep, geothermal pool. The water is a constant 93 degrees Fahrenheit, and it’s incredibly low in oxygen. It’s one of the most extreme aquatic environments on Earth. And it is the only place in the entire world where a tiny, iridescent blue fish lives: the Devils Hole pupfish. Michelle: The only place? The entire species lives in one cave? Mark: The entire species. Their population sometimes drops to just a few dozen individuals. They are, without a doubt, one ofthe rarest fish on the planet. They live, breed, and die on a single shallow rock shelf in this one pool. That’s their entire universe. Michelle: Wow. That is so precarious. What’s threatening them? I assume it’s not other fish. Mark: It’s us, of course. In the 1960s, agricultural developers started pumping groundwater nearby, and the water level in Devils Hole began to drop. This exposed their crucial spawning shelf, and the population crashed. It led to a landmark Supreme Court case, Cappaert v. United States, where the court actually ruled that the pupfish’s right to water superseded the developer’s. Michelle: A Supreme Court case for a tiny fish! That’s amazing. So they were saved? Mark: They were saved from that threat. But their existence is so fragile. A few years ago, some drunk guys broke into the fenced-off area, went skinny-dipping, and left a dead pupfish floating in the water. The incident was caught on camera and they were charged with felonies. One dead fish was a federal crime because the population is that low. Michelle: That’s both infuriating and a testament to how much effort is going into protecting them. But how do you manage a species that’s always one drunken night or one slight water level drop away from extinction? Mark: You build a backup. This is where the story enters the realm of science fiction. Fearing the worst, the government spent four and a half million dollars to build a perfect replica of Devils Hole in a nearby facility. They call it the Ash Meadows Fish Conservation Facility, but Kolbert essentially describes it as Devils Hole Jr. Michelle: A four-and-a-half-million-dollar fish tank? Mark: It’s so much more than that. It’s a hundred-thousand-gallon concrete bunker designed to be a perfect simulacrum. They meticulously recreated the dimensions of the rock shelf, they use chillers and heaters to keep the water at exactly 93 degrees, they even have special lights that mimic the precise angle and intensity of sunlight that hits the real Devils Hole throughout the day. Michelle: They’re playing God for a fish. Mark: They have to. They even have a "larval rearing room" where they raise baby pupfish on special algae wafers because the food chain in the replica isn't quite right. Biologists are there 24/7. It is a species on full life support. Michelle: This is blowing my mind. It’s like a fish ICU. But it raises a huge question for me. If a species can only survive in a man-made bunker, fed by scientists, is it even a 'wild' animal anymore? It feels like we’ve turned it into a living museum piece. Mark: That is the exact philosophical knot Kolbert is untangling. The pupfish is what’s known as a "conservation-reliant" species. It has no hope of surviving without constant, intensive human intervention. The line between wild and captive, between nature and artifice, has completely dissolved. We broke its habitat, so now our only way to "save" it is to build it a new, artificial one.

Michelle: So whether it’s the Asian carp or the pupfish, the story is the same. We intervene, we mess things up, and our solution is to intervene even more, on a more granular, more controlling level. Mark: Exactly. The book is full of these stories. Creating "super corals" in a lab to withstand the ocean acidification we caused. Genetically engineering mice to be immune to the diseases they carry. The title, Under a White Sky, even refers to a geoengineering proposal to shoot reflective particles into the stratosphere to dim the sun and counteract global warming—literally changing the color of the sky to fix the climate we broke. Michelle: That’s terrifying. It feels like we’re kids who took apart a watch and now we’re trying to put it back together with a hammer and glue, just making it worse with every step. Mark: That’s a great way to put it. Kolbert quotes Rachel Carson, who wrote that the phrase "control of nature" was "conceived in arrogance." And what Kolbert shows is that we’ve inherited the consequences of that arrogance. The new job of humanity isn't just to control nature, but to control the out-of-control systems we built to control nature in the first place. It’s control of the control. Michelle: It’s a really humbling, and honestly, a little scary thought. The book has been praised for being so insightful, but I can see why some readers find it bleak. It doesn't offer easy answers. It just shows us the tangled mess we're in. Mark: There are no easy answers. The book forces you to sit with the complexity. We have this impulse to fix things, to engineer our way out of trouble. But what if the tools we're using are just bigger versions of the ones that got us into this mess? Michelle: It makes you wonder, what problem are we 'solving' today that will become the next generation's flying carp? It forces you to look at every grand technological 'fix' with a healthy dose of skepticism. We'd love to hear what you think. What's an example of an unintended consequence you've seen in your own world, big or small? Let us know your thoughts. Mark: It’s a conversation we all need to be having. The future is going to be a very hands-on affair. Michelle: For better or for worse. Mark: This is Aibrary, signing off.