Of course all this hit the people. As Tom had said, even fifty years ago many of the locals in Siberia still lived as hunter-gatherers, following the reindeer around. Ironically the programs to relocate them out of there were paid for by the environment taxes paid by the big oil, gas, aluminium, and logging companies that had done so much damage to the area in the first place.

And then you had the methane.

Right around the poles huge quantities of methane, carbon dioxide, and other volatiles were locked up in hydrate deposits, kept stable by the low ocean temperatures and the pressure of the land and water above. The physics of it seemed simple enough. The peculiar geometry of water molecules makes them difficult to pack into a solid structure when they freeze. So “solid” ice contains a lot of empty space — room enough to trap other molecules, such as methane. And there is a lot of methane to be found on the seabed; there isn’t much oxygen down there, and anerobic decay processes release a lot of the gas.

When the temperature rose, that natural cage was broken open. The consequence was “methane burps” of the kind Tom was unlucky enough to have encountered.

But that was a localized event, I realized, lethal as it was if you happened to be in the way. The Warming, however, was nothing if not global. There was more methane down there in the hydrate layers than in all the world’s fossil fuel reserves, and methane, though it doesn’t last as long in the atmosphere, is in the short term twenty times as potent a greenhouse gas as our old buddy carbon dioxide.

So what would happen, I wondered vaguely, if this went on, if all that methane was released? I tabbed through pages on my softscreen, seeking answers. But my question chains petered out; my softscreen couldn’t answer. I sat back, tugging at a thread of speculation.

I admit I didn’t know much about the Warming, about climate change in the Arctic or anywhere else. Why should I? The planet was warming up, my body was growing older, it was all just part of the world I’d grown up in; you either obsessed about it, or accepted it and got on with your life. And besides, we had dumped the automobile, we had accepted the need to run the Stewardship. We were managing the pain, weren’t we?

But if those hydrate deposits all gave way, instead of the world just becoming slowly shabbier… I thought there was some bad news buried in here. Maybe very bad news. And on some level I just didn’t want to know.

Was there anything to be done about it? I cleared the softscreen, took a stylus, and began to doodle.

I kept being distracted by the environment of the flight.

If I miss driving, I miss flying more. When I was a kid my parents flew all the time. At the peak of their careers they had pretty much sewn up the Miami Beach market for corporate eventing, and scarcely a weekend went by without them managing a sales conference or marketing-strategy session at one resort hotel or another. All that was local, but to set up the deals they had to travel to where the customers were. When they got the chance, they would take us kids, John and me. Our teachers would kick up a stink, as in those days you were still expected to attend school for the regulation five days a week. But for better or worse my parents took the blows, and we flew.

We kids loved seeing the great centers of business across the country, from New York to San Francisco, Chicago down to Houston. A few times we traveled overseas, to Europe and Africa and even Japan once, though my mother worried about the effect of such long-haul trips. The whole thing was a great eye-opener that gave me a real sense of the planet I lived on.

But most of all I just loved to fly. I relished being in a vast machine that had the energy to hurl itself into the sky. I was always fascinated to come into a major airport, and to glimpse all those other sparks of light in the sky, and the mothlike shapes of more planes on the ground; you got a real sense of the millions of tons of metal suspended in the air over the continental United States, a great dome of dynamic engineering speckled with fragile humanity, every minute of every day. All gone now, of course. Now nobody flies — nobody but the very rich. It’s the same logic that took away the automobile: we’ve had to sacrifice some freedom to survive. I accept all that, and most of the time, like everybody else, I don’t think about it. But I still miss flying.

Jack Joy was leaning over to see what I was doing. Some instinct made me blank out the softscreen.

He leaned back with his pudgy hands up. “Sorry. Didn’t mean to pry.”

“It’s OK.”

“Work? Stuff about climate change? That’s your job?”

“No. It’s my son’s, in a way…”

I felt guilty about shutting him out like that. I told him a little about Tom’s work, and the accident.

He nodded. “Good kid. You must be proud.”

“I guess. More relieved he’s still around.”

“And now you’re boning up on global warming?”

“I kind of feel the world has targeted me, or anyhow my son.”

“I get it,” he said. He tapped his nose. “Know your enemy.”

“Not that I want the Earth to be my enemy.”

“Ah.” He waved a hand dismissively. “Neither enemy nor friend. It’s just a stage, right? A stage for us humans to strut our magnificent stuff.” He stuck out his belly as he said this.

I couldn’t help laughing at him. “I don’t know if I’d say that. The Die-back—”

“Who cares about that? You see, there I would take issue with your son. All that DNA cataloguing bullshit? Forget it! Let it happen. Let them all die off. So what?”

I couldn’t believe him. “Are you serious?”

“Of course I am.” He leaned closer, conspiratorially. “Listen to me. The Die-back has been going on for millennia. Ever since the Ice Age. First we wiped out the big mammals. In North America, the mammoths and the cave bears and the lions, pow, whole populations pop like soap bubbles when the first guy with a funny little spear wanders over from Asia. Australia the same. Asia and Africa it’s different, but there the animals evolved alongside us, and had time to get used to us.” He cackled. “I guess they learned to run fast. But now we’re working our way through them, too, and the smaller critters, the birds of the air and the fish of the sea, the plants and the bugs. Whatever.”

“And you don’t think that’s a bad thing?”

“Two words,” he said. “Morally neutral.It just happened. There have been mass extinctions before, worse than this mother will ever be. And every time, you know what? Life bounces back. An evolutionary rebound, the biologists call it.” He winked at me. “So you just have to let it fix itself, and in the meantime sit back and enjoy the view. They don’t report this stuff—”

“But it’s true,” I finished for him.

He glanced at me and grinned. “Lethe, you know me already.”

“I don’t often hear people curse like that. Lethe. ”

“You don’t? Actually there’s a scientific hypothesis called Lethe. You’ve heard of Gaia?”

“Sure.” Named for a Greek earth-goddess, Gaia was a model of the Earth’s unified systems and processes, from the rock cycle, to the exchange of gases between air and ocean, to the vast cycling of matter and energy which sustained life, and which life sustained in its turn. All this was the paradigm among biologists, and a staple in Eco 101 for everybody else.

Jack said, “ ‘Lethe’ is the opposite to Gaia. An anti-Gaia, if you will. The Warming isn’t a simple event. Everything is working together, different effects reinforcing — just like Gaia, but now the Earth has begun working to destroy itself, as opposed to sustaining itself. Ask a biologist; you’ll see.

“But you know what Lethe actually means? It’s from Greek myth. Lethe was a river in Hades, which if you drank from it, would wash away your memory. Later on it was used by Shakespeare, to mean ‘death.’ Lethal — you see. But the original meaning kind of makes sense, doesn’t it?”