Yes, that's true. That's why I made reference in the article to the Vikings chopping down all the trees in Iceland. The Easter Islanders also spring to mind.

Humans have shaped the environment since before we were even the species we are today. But not like this. And it's not a question of intelligence. Nowhere did I claim that people were less smart 100,000 years ago. In fact, selection pressure being what it was, I suspect they were probably smarter on average.

But they couldn't do what we do because our discoveries and technologies are built on the discoveries of the past. They could chop down trees and burn them. But they couldn't frack for natural gas. They couldn't bulldoze 80,000 acres of a single forest every single day. Their power to do harm to the environment was limited by the technology they possessed. As is ours. But our power is far greater than theirs.