To avoid destroying itself, the human race would have to do something deeply unnatural, something no other species has ever done or could ever do: constrain its own growth (at least in some ways). Brown tree snakes in Guam, water hyacinth in African rivers, rabbits in Australia, Burmese pythons in Florida—all these successful species have overrun their environments, heedlessly wiping out other creatures. Not one has voluntarily turned back.
