Humans’ greenhouse gas emissions throw next ice age off schedule

In The World Without Us, writer Alan Weisman speculates on what might happen to the Earth if people disappeared tomorrow. Much of the change is predictable: Cities crumble, plants proliferate and nobody has to worry about election-year politics anymore.

But what would happen to the heat-trapping gases people have pumped into the air with their machines? Would carbon dioxide get sucked down into newborn forests, quickly cleansing the air (if not the airwaves) back to a pristine state?

Well, no.