Some of the earliest clues scientists had that Earth's climate has changed over time were mismatches between the fossil record and a current ecosystem. How could this palm tree have grown in Wyoming? Why have fossils of the tropical breadfruit tree been found as far north as Greenland? These cold places must have once been warm and wet. The world is not as it has always been.

And somehow, despite the tumult, species adapted, moving thousands of miles to habitats where they could survive. Won't species today just do the same as temperatures rise in the years ahead?

It seems they may not have the chance. A new paper in the journal Science finds that climate change is now set to occur at a pace "orders of magnitude more rapid" than at any other time in the last 65 million years. That breakneck speed may mean extinction for species that cannot keep up.