“I took the job in the first place,” Walter said, “because I couldn’t sleep at night. I couldn’t stand what was happening to the country. Clinton had done less than zero for the environment. Net fucking negative. Clinton just wanted everybody to party to Fleetwood Mac. ‘Don’t stop thinking about tomorrow?’ Bullshit. Not thinking about tomorrow was exactly what he did environmentally. And then Gore was too much of a wimp to let his green flag fly, and too nice a guy to fight dirty in Florida. I was still halfway OK as long as I was in St. Paul, but I kept having to drive all over the state for the Conservancy, and it was like having acid thrown in my face every time I passed the city limits. Not just the industrial farming but the sprawl, the sprawl, the sprawl. Low-density development is the worst. And SUVs everywhere, snowmobiles everywhere, Jet Skis everywhere, ATVs everywhere, two-acre lawns everywhere. The goddamned green monospecific chemical-drenched lawns.”

“Here are the maps,” Lalitha said.

“Yeah, these show the fragmentation,” Walter said, handing Katz two laminated maps. “This one is undisturbed habitat in 1900, this one’s undisturbed habitat in 2000.”

“Prosperity will do that,” Katz said.

“The development was so stupidly done, though,” Walter said. “We still might have enough land for other species to survive if it wasn’t all so fragmented.”

“Nice fantasy, I agree,” Katz said. In hindsight, he supposed it was inevitable that his friend would become one of those people who carried around laminated literature. But he was still surprised by what an angry crank Walter had become in the last two years.

“This was what was keeping me awake at night,” Walter said. “This fragmentation. Because it’s the same problem everywhere. It’s like the internet, or cable TV-there’s never any center, there’s no communal agreement, there’s just a trillion little bits of distracting noise. We can never sit down and have any kind of sustained conversation, it’s all just cheap trash and shitty development. All the real things, the authentic things, the honest things are dying off. Intellectually and culturally, we just bounce around like random billiard balls, reacting to the latest random stimuli.”

“There’s some pretty good porn on the internet,” Katz said. “Or so I’m told.”

“I wasn’t accomplishing anything systemic in Minnesota. We were just gathering little bits of disconnected prettiness. There are approximately six hundred breeding bird species in North America, and maybe a third of them are getting clobbered by fragmentation. Vin’s idea was that if two hundred really rich people would each pick one species, and try to stop the fragmentation of their strongholds, we might be able to save them all.”

“The cerulean warbler is a very choosy little bird,” Lalitha said.

“It breeds in treetops in mature deciduous forest,” Walter said. “And then, as soon as the babies can fly, the family moves down into the understory for safety. But the original forests were all cut down for timber and charcoal, and the second-growth forests don’t have the right kind of understory, and they’re all fragmented with roads and farms and subdivisions and coal-mining sites, which makes the warbler vulnerable to cats and raccoons and crows.”

“And so, before you know it, no more cerulean warblers,” Lalitha said.

“That does sound tough,” Katz said. “Although it is just one bird.”

“Every species has an inalienable right to keep existing,” Walter said.

“Sure. Of course. I’m just trying to figure out where this is coming from. I don’t remember you caring about birds when we were in college. Back then, as I recall, it was more about overpopulation and the limits to growth.”

Walter and Lalitha again exchanged glances.

“Overpopulation is exactly what we want you to help us with,” Lalitha said.

Katz laughed. “Doing my best with that already.”

Walter was shuffling through some laminated charts. “I started walking it back,” he said, “because I still wasn’t sleeping. You remember Aristotle and the different kinds of causes? Efficient and formal and final? Well, nest-predation by crows and feral cats is an efficient cause of the warbler’s decline. And fragmentation of the habitat is a formal cause of that. But what’s the final cause? The final cause is the root of pretty much every problem we have. The final cause is too many damn people on the planet. It’s especially clear when we go to South America. Yes, per capita consumption is rising. Yes, the Chinese are illegally vacuuming up resources down there. But the real problem is population pressure. Six kids per family versus one point five. People are desperate to feed the children that the pope in his infinite wisdom makes them have, and so they trash the environment.”

“You should come with us to South America,” Lalitha said. “We drive along these little roads, there’s terrible exhaust from bad engines and too-cheap gasoline, the hillsides are all denuded, and the families all have eight or ten children, it’s really sickening. You should come along with us sometime and see if you like what you see down there. Because it’s coming soon to a theater near you.”

Crackpot, Katz thought. Hot little crackpot.

Walter handed him a laminated bar chart. “In America alone,” he said, “the population’s going to rise by fifty percent in the next four decades. Think about how crowded the exurbs are already, think about the traffic and the sprawl and the environmental degradation and the dependence on foreign oil. And then add fifty percent. And that’s just America, which can theoretically sustain a larger population. And then think about global carbon emissions, and genocide and famine in Africa, and the radicalized dead-end underclass in the Arab world, and overfishing of the oceans, illegal Israeli settlements, the Han Chinese overrunning Tibet, a hundred million poor people in nuclear Pakistan: there’s hardly a problem in the world that wouldn’t be solved or at least tremendously alleviated by having fewer people. And yet”-he gave Katz another chart-“we’re going to add another three billion by 2050. In other words, we’re going to add the equivalent of the world’s entire population when you and I were putting our pennies in UNICEF boxes. Any little things we might do now to try to save some nature and preserve some kind of quality of life are going to get overwhelmed by the sheer numbers, because people can change their consumption habits-it takes time and effort, but it can be done-but if the population keeps increasing, nothing else we do is going to matter. And yet nobody is talking about the problem publicly. It’s the elephant in the room, and it’s killing us.”

“This is all sounding more familiar,” Katz said. “I’m remembering some rather lengthy discussions.”

“I was definitely into it in college. But then, you know, I did some breeding myself.”

Katz raised his eyebrows. Breeding was an interesting way of speaking of one’s wife and children.

“In my own way,” Walter said, “I guess I was part of a larger cultural shift that was happening in the eighties and nineties. Overpopulation was definitely part of the public conversation in the seventies, with Paul Ehrlich, and the Club of Rome, and ZPG. And then suddenly it was gone. Became just unmentionable. Part of it was the Green Revolution-you know, still plenty of famines, but not apocalyptic ones. And then population control got a terrible name politically. Totalitarian China with its one-child policy, Indira Gandhi doing forced sterilizations, American ZPG getting painted as nativist and racist. The liberals got all scared and silent. Even the Sierra Club got scared. And the conservatives, of course, never gave a shit in the first place, because their entire ideology is selfish short-term interest and God’s plan and so forth. And so the problem became this cancer that you know is growing inside you but you decide you’re just not going to think about.”