Page 823 - Enders_Game_Full_Book

"You haven't known us long enough," said Planter. "We haven't told you everything because we were afraid you'd think we were silly. Now you'll know that we aren't silly, we're just acting out what a virus tells us to do. We're slaves, not fools."
It startled Ender to realize that Planter had just confessed that the pequeninos still took some pains to try to impress human beings. "What behaviors of yours have anything to do with planetary regulation?"
"Trees," said Planter. "How many forests are there, all over the world? Transpiring constantly. Turning carbon dioxide into oxygen. Carbon dioxide is a greenhouse gas. When there's more of it in the atmosphere, the world gets warmer. So what would we do to make the world get cooler?"
"Plant more forests," said Ela. "To use up more CO2 so that more heat could escape into space." "Yes," said Planter. "But think about how we plant our trees."
The trees grow from the bodies of the dead, thought Ender. "War," he said.
"There are quarrels between tribes, and sometimes they make small wars," said Planter. "Those would be nothing on a planetary scale. But the great wars that sweep across the whole world-- millions and millions of brothers die in these wars, and all of them become trees. Within months the forests of the world could double in size and number. That would make a difference, wouldn't it?"
"Yes," said Ela.
"A lot more efficiently than anything that would happen through natural evolution," said Ender.
"And then the wars stop," said Planter. "We always think there are great causes for these wars, that they're struggles between good and evil. And now all the time they are nothing but planetary regulation."
"No," said Valentine. "The need to fight, the rage, that might come from the descolada, but it doesn't mean the causes you fought for are--"
"The cause we fight for is planetary regulation," said Planter. "Everything fits. How do you think we help with warming the planet?"
"I don't know," said Ela. "Even trees eventually die of old age."
"You don't know because you've come during a warm time, not a cold one. But when the winters get bad, we build houses. The brothertrees give themselves to us to make houses. All of us, not just the ones who live in cold places. We all build houses, and the forests are reduced by half, by three- quarters. We thought this was a great sacrifice the brothertrees made for the sake of the tribe, but now I see that it's the descolada, wanting more carbon dioxide in the atmosphere to warm the planet."