Joan laughed. “Oh, Alyce—”

“On your feet.”

Joan imagined Alyce jollying some timid student of chimps or baboons into the dark dangers of the bush, but she complied. She kicked off her shoes. And, with Alyce’s help, she clambered on to a coffee table.

She was overwhelmed by a self-conscious absurdity. With her conference literally under attack, how could she think she could get up on her hind legs and lecture an audience of her peers about how to save the planet? But here she was, and people were already staring. She clapped her hands until a quorum was turned her way.

“Guys, I apologize,” Joan began, hesitantly, “but I need your attention. We’ve worked hard all day, but I’m afraid I’m not going to let up on you now.

“We’re here to discuss mankind’s impact on the world against the background of our evolutionary emergence. We’ve assembled here a unique group, cross-disciplinary, international, influential. Probably nobody alive knows more about how and why we got into this mess than we do, here tonight. And so we have an opportunity — maybe unique, probably unrepeatable — to do something more than just talk about it.

“I’ve had an additional purpose, a covert purpose, in calling you together. I want to use this evening as an extra session — an unusual session — if it goes the way I hope, a session that may spark off an entirely new thread. A new hope.” She felt embarrassed at this unscientific language, and there were plenty of pursed lips and raised eyebrows. “So charge your glasses and vials and tubes, find somewhere to sit, and we’ll begin.”

And so, in this nondescript hotel bar, as the conference attendees settled on dragged-over chairs, stools, and tabletops, she began to talk about mass extinction.

Joan smiled. “Even paleontologists, like me, understand cooperation and complexity. Papa Darwin himself, toward the end of Origin of Species, came up with a metaphor that sums up the whole thing.” Feeling awkward, she read from a scrap of paper. “It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by the laws acting around us…”

She put down the paper. “But right now that entangled bank is in trouble. You don’t need me to spell it out for you.

“We are undoubtedly in the middle of a mass extinction. The specifics are heartbreaking. In my lifetime the last wild elephants have disappeared from the savannahs and forests. No more elephants! How will we ever be able to justify that to our grandchildren? In my lifetime, we have already lost a quarter of all the species extant in the year 2000. If we keep going at the current rate, we will destroy some two-thirds of the species extant in 1900 by the end of this century. The event’s severity already puts it up there with the previous big five of Earth’s battered history.

“Meanwhile human-induced climate change has already turned out to be much more severe than any but a few scientists predicted. Africa’s major coastal cities, from Cairo to Lagos, have been partially or completely flooded, displacing tens of millions of people. Bangladesh is almost totally inundated. If it wasn’t for billion-dollar flood defenses, even Florida would be an archipelago. And so on.

“The fault is all ours. We have become overwhelming. About one in twenty of all the people who have ever existed is alive today, compared to just one in a thousand of other species. As a result we are depleting the Earth.

“But even now the question is still asked: Does it really matter? So we lose a few cute mammals, and a lot of bugs nobody ever heard of. So what? We’re still here.

“Yes, we are. But the ecosystem is like a vast life-support machine. It is built on the interactions of species on all scales of life, from the humblest fungi filaments that sustain the roots of plants to the tremendous global cycles of water, oxygen, and carbon dioxide. Darwin’s entangled bank, indeed. How does the machine stay stable? We don’t know. Which are its most important components? We don’t know. How much of it can we take out safely? We don’t know that either. Even if we could identify and save the species that are critical for our survival, we wouldn’t know which species they depend on in turn. But if we keep on our present course, we will soon find out the limits of robustness.

“I may be biased, but I believe it will matter a great deal if we were to die by our own foolishness. Because we bring to the world something that no other creature in all its long history has had, and that is conscious purpose. We can think our way out of this.

“So my question is — consciously, purposefully, what are we going to do?”

She ground to a halt, impassioned, uncertain, standing on her coffee table.

Some people were nodding. Others were looking bored.

Alison Scott was the first to stand up, long legs unfolding languidly. Joan held her breath.

“You aren’t telling us anything new, Joan. The slow death of the biosphere is — ah — banal. A cliché. And I have to point out that what we have done is in fact inevitable. We are animals, we continue to behave like animals, and we always will.” There was a grumble of dissent. Scott plowed on, “Other animals have been known to eat themselves to extinction. In the twentieth century reindeer were introduced to a small island in the Bering Sea. An initial population of twenty-nine ballooned to six thousand in twenty years. But their food was slow-growing lichens, which had no time to recover from their intensive grazing.”

“But,” somebody shouted out, “reindeer don’t know anything about ecology.”

Scott said smoothly, “We’ve done this throughout history. The example of the Polynesian islands is well known. The Mideast city of Petra—”

As Joan had hoped, the group broke up into arguing clusters.

“…those people of the past who failed to manage their resources were guilty simply of failing to solve a difficult ecological problem…”

“We are already handling energy and mass flows on a scale that rivals natural processes. Now we have to use those powers consciously…”

“But the risks of tinkering with the fundamentals of an overcrowded planet…”

“All these technological measures would themselves cost energy, and so would actually add to the planetary burden of waste heat…”

“Our civilization has no common agenda. How would you propose to resolve the political, legal, ethical, cultural, and financial issues implicit in your proposals?…”

“I’ve been listening to this kind of technocratic horseshit all my adult life! What is this, a NASA funding pitch?”

“I say fuck the ecosystem. Who needs horny-backed toads anyhow? Let’s go for a drastic simplification. All you’ve got to do is soak up cee oh two, pump out oxygen, and regulate the heat. How hard can it be?”

“So, madam, you really want to live in Blade Runner world?”

Joan had to intervene again to pull the group back together. “We need a unity of will, a mobilization we haven’t seen before. But maybe we haven’t yet hit on the solution we should be reaching for.”

“Precisely,” said Alison Scott, and she stood up again. She rested her hands on the shining hair, blue and green, of her two daughters. “Big engineering is a defunct dream of the twentieth century. The solution is not out there; it will be found in us.”

More hostility greeted these pronouncements. “She means engineering babies, like her own two little freaks.”

“I’m talking about evolution,” Scott snapped. “That’s what happens to a species when the environment changes. Throughout our history we have proved to be a remarkably adaptable species.”