Now, in the bright expanse of the hotel's lobby, Hammer gave an account of his trying journey from San Francisco, of a terrifying air pocket that dropped the plane two thousand feet, his neighbour's panic attack, of an inedible sandwich, until Beard's bladder could stand no more and he excused himself. When he came back he found his friend sitting in reception, rattling emails on his laptop.

'Scientific American are coming,' he said, without breaking stride. 'And that thin guy from the New York Times.'

'This had better work,' Beard said. The electric jackhammer had thrown a long shadow.

'Some local business has put together a giant neon sign that says Lordsburg, exclamation mark. They want to situate it a quarter-mile from us, and have it light up when we turn on.'

'As long as they supply the quarter-mile of cable.'

Hammer put his laptop away. He looked weary, even a little depressed. 'They want it on all night. And the Chamber of Commerce has lined up an army marching band from outside Las Cruces.'

'I thought we were having a girl country group.'

'In New Mexico, or this part of it, you have to have the army first. We also have a fly-past from the air-force base. The girls will play later, and of course, we'll be powering their amps.' In what looked like an effort to appear cheerful, he punched Beard's arm. 'Sunlight, water and money make electricity makes more money! My friend. It's going to happen.'

They agreed to have an early dinner and to stay the night and leave straight after Beard had seen his doctor.

'But listen, Chief,' Hammer said as they took their places in the deserted dining room. 'Don't let him make you ill. This is not the time.'

'That's my worry too. A diagnosis is a kind of modern curse. If you didn't go and see these people, you wouldn't get whatever it is they want you to have.'

With wine and water they raised a toast to magical thinking, then they continued a conversation they had been having by email for some months. To an eavesdropper it would have sounded like the essence of commercial tedium, but to the two men it was a matter of urgency. How many orders for panels were necessary to bring the unit cost down to the point at which they could feasibly claim that a mediumsized artificial-photosynthesis plant could generate electricity as cheaply as coal? The energy market was highly conservative. There was no premium for being virtuous, for not screwing up the climate system. Orders for seven thousand panels, this was their best calculation. Much would depend on whether they could reliably power Lordsburg and its environs night and day for a year, through all kinds of weather. And it also depended on the Chinese, how fast they could move, and how plausibly they could be threatened by the prospect of losing the business. In that respect, the recession helped, but it would also depress demand for panels, if not for energy. They went round this topic a few times, quoting figures, plucking others from the air, then Hammer leaned forward and said confidentially, as though the sole waiter on the far side of the restaurant might hear him, 'But, Chief, you can be straight with me. Tell me. Is it true, the planet's getting cooler?'

'What?'

'You keep telling me the arguments are over, but they're not. I'm hearing it everywhere. Last week some woman professor of atmosphere studies or something was saying so on public television.'

'Whoever she says she is, she's wrong.'

'And I'm hearing it everywhere from business people. It seems like it's building. They're saying the scientists have gotten it wrong but don't dare to admit it. Too many careers and reputations on the line.'

'What's their evidence?'

'They're saying a point-seven-degree rise since pre-industrial times, that's two hundred and fifty years, is negligible, well within usual fluctuations. And the last ten years have been below the average. We've had some bad winters here – that doesn't help our cause. And they're also saying that too many people are going to get rich on the Obama handouts and tax breaks to want to tell the truth. Then there are all these scientists, including the one I was talking about, who've signed up to the Senate Minority Report on Climate Change – you must have seen that stuff.'

Beard hesitated, then called for more wine. That was the trouble with some of these Californian reds, they were so smoothly accessible, they went down like lemonade. But they were sixteen per cent alcohol. He could not help feeling that this conversation was beneath him. It wearied him, like talking about or against religion, or crop circles and UFOs for that matter. He said, 'It's zero point eight now, it's not negligible in climate terms, and most of it has happened in the last thirty years. And ten years is not enough to establish a trend. You need at least twenty-five. Some years are hotter, some are cooler than the year before, and if you drew a graph of average yearly temperatures it would be a zigzag, but a rising zigzag. When you take an exceptionally hot year as your starting point, you can easily show a decline, at least for a few years. That's an old trick, called framing, or cherry-picking. As for these scientists who signed some contrarian document, they're in a minority of a thousand to one, Toby. Ornithologists, epidemiologists, oceanographers and glaciologists, salmon fishermen and ski-lift operators, the consensus is overwhelming. Some weak-brained journalists write against it because they think it's a sign of independent thinking. And there's plenty of attention out there for a professor who'll speak against it. There are bad scientists, just like there are rotten singers and terrible cooks.'

Hammer looked sceptical. 'If the place isn't hotting up, we're fucked.'

As he refilled his glass, Beard thought how strange it was, that after being associates for all these years, they had rarely discussed the larger issue. They had always concentrated on the business, the matter in hand. Beard also noticed that he himself was close to being drunk.

'Here's the good news. The UN estimates that already a third of a million people a year are dying from climate change. Bangladesh is going down because the oceans are warming and expanding and rising. There's drought in the Amazonian rainforest. Methane is pouring out of the Siberian permafrost. There's a meltdown under the Greenland ice sheet that no one really wants to talk about. Amateur yachtsmen have been sailing the North-West Passage. Two years ago we lost forty per cent of the Arctic summer ice. Now the eastern Antarctic is going. The future has arrived, Toby.'

'Yeah,' Hammer said. 'I guess.'

'You're not convinced. Here's the worst case. Suppose the near impossible – the thousand are wrong and the one is right, the data are all skewed, there's no warming. It's a mass delusion among scientists, or a plot. Then we still have the old stand-bys. Energy security, air pollution, peak oil.'

'No one's going to buy a fancy panel from us just because the oil's going to run out in thirty years.'

'What's wrong with you? Trouble at home?'

'Nothing like that. Just that I put in all this work, then guys in white coats come on TV to say the planet's not heating. I get spooked.'

Beard laid a hand on his friend's arm, a sure sign that he was well over his limit. 'Toby, listen. It's a catastrophe. Relax!'

By nine thirty, the two men, exhausted by travel, were ready for their beds and went up in the elevator together. Beard's floor was first. He said goodnight to Hammer, then set off with his luggage down many long corridors at right angles, murmuring to himself his room number to keep it fresh in his mind, and stopping occasionally to bend, swaying, in front of wall plaques with designations like '309-331', while his own, 399, was not mentioned or implied anywhere. So he kept going, eventually arriving from a different direction back by the elevator, or one like it, with a similar brown apple core reclining in a sand-filled ashtray. With a welling sense of victimhood he set off again, eventually passing the elevator once more. He was well into his third circuit before he understood that he was holding the room card upside down and his destination was 663, on another floor. He rode up, found his room, dumped his luggage just inside the door and made for the minibar, from which he took a brandy and an outsized bar of chocolate and sat with them on the edge of his bed.