Pelorat frowned. "You can tell all that?" He looked at the cloud layer as though he thought it would, or should, speak to him now, but, of course, it didn't.
"Not only that," said Trevize, "but if you'll look at the polar regions, you'll see that there are no breaks in the cloud layer as there are away from the poles. Actually, there are breaks, but through the breaks you see ice, so it's a matter of white on white."
"Ah," said Pelorat. "I suppose you expect that at the poles."
"Of habitable planets, certainly. Lifeless planets might be airless or waterless, or might have certain stigmata showing that the clouds are not water or** clouds, or that the ice is not water ice. This planet lacks those stigmata, so we know we are looking at water clouds and water ice.
"The next thing we notice is the size of the area of unbroken white on the day side of the terminator, and to the experienced eye it is at once seen as larger than average. Furthermore, you can detect a certain orange glint, a quite faint one, to the reflected light, and that means Comporellon's sun if rather cooler than Terminus's sun. Although Comporellon is closer to its sun than Terminus is to hers, it is not sufficiently closer to make up for its star's lower temperature. Therefore, Comporellon is a cold world as habitable worlds go."
"You read it like a film, old chap," said Pelorat admiringly.
"Don't be too impressed," said Trevize, smiling affectionately. "The computer has given me the applicable statistics of the world, including its slightly low average temperature. It is easy to deduce something you already know. In fact, Comporellon is at the edge of an ice age and would be having one, if the configuration of its continents were more suitable to such a condition."
Bliss bit at her lower lip. "I don't like a cold world."
"We've got warm clothing," said Trevize.
"That doesn't matter. Human beings aren't adapted to cold weather, really. We don't have thick coats of hair or feathers, or a subcutaneous layer of blubber. For a world to have cold weather seems to indicate a certain indifference to the welfare of its own parts."
Trevize said, "Is Gaia a uniformly mild world?"
"Most of it, yes. There are some cold areas for cold-adapted plants and animals, and some hot areas for heat-adapted plants and animals, but most parts are uniformly mild, never getting uncomfortably hot or uncomfortably cold, for those between, including human beings, of course."
"Human beings, of course. All parts of Gaia are alive and equal in that respect, but some, like human beings, are obviously more equal than other,"
"Don't be foolishly sarcastic," said Bliss, with a trace of waspishness. "The level and intensity of consciousness and awareness are important. A human being is a more useful portion of Gaia than a rock of the same weight would be, and the properties and functions of Gaia as a whole are necessarily weighted in the direction of the human being-not as much so as on your Isolate worlds, however. What's more, there are times when it is weighted in other directions, when that is needed for Gaia as a whole. It might even, at long intervals, be weighted in the direction of the rocky interior. That, too, demands attention or, in the lack of that attention all parts of Gaia might suffer. We wouldn't want an unnecessary volcanic eruption, would we?"
"No," said Trevize. "Not an unnecessary one."
"You're not impressed, are you?"
"Look," said Trevize. "We have worlds that are colder than average and worlds that are warmer; worlds that are tropical forests to a large extent, and worlds that are vast savannahs. No two worlds are alike, and every one of them is home to those who are used to it. I am used to the relative mildness of Terminus-we've tamed it to an almost Gaian moderation, actually-but I like to get away, at least temporarily, to something different. What we have, Bliss, that Gaia doesn't have, is variation. If Gaia expands into Galaxia, will every world in the Galaxy be forced into mildness? The sameness would be unbearable."
Bliss said, "If that is so, and if variety seems desirable, variety will be maintained."
"As a gift from the central committee, so to speak?" said Trevize dryly. "And as little of it as they can bear to part with? I'd rather leave it to nature."
"But you haven't left it to nature. Every habitable world in the Galaxy has been modified. Every single one was found in a state of nature that was uncomfortable for humanity, and every single one was modified until it was as mild as could be managed. If this world here is cold, I am certain that is because its inhabitants couldn't warm it any further without unacceptable expense. And even so, the portions they actually inhabit we can be sure are artificially warmed into mildness. So don't be so loftily virtuous about leaving it to nature."
Trevize said, "You speak for Gaia, I suppose."
"I always speak for Gaia. I am Gaia."