Crocodiles and Palm Trees in the Artic?
In even the bleakest climate change scenarios for the end of this century, science has offered hope that global warming would eventually slow down. But a new study published Monday eliminates such hope, projecting temperatures that rise lockstep with carbon emissions until the last drops of oil and lumps of coal are used up. Global temperatures will increase on average by 8 degrees Celsius (14.4 degrees F) over preindustrial levels by 2300 if all of Earth’s fossil fuel resources are burned, In the Arctic, average temperatures would rise by 17 degrees C (30.6 degrees F). If these temperatures do become reality, greenhouse gases would transform Earth into a place where food is scarce, parts of the world are uninhabitable for humans, and many species of animals and plants are wiped out, experts say.
"It would be as unrecognizable to us as a fully glaciated world," says Mylles Allen, head of a climate dynamics group at the University of Oxford in the United Kingdom. Allen was not involved in the new study, but his research has focused on carbon’s cumulative impacts on climate. It also would heat the world to a level approaching that of the early Eocene period, 52 million to 56 million years ago, when palm trees grewas far North as Alaska and crocodiles swam in the Arctic.
Mammals survived Eocene temperatures; this is when early primates appeared. Some horses, however, shrank to the size of house cats, adjusting through evolution to a diet altered either by heat or carbon. Today's organisms and ecosystems may not be able to adapt to warming over the next 200 to 300 years—an instant on the geological time scale, says Scott Wing, the Smithsonian Institution’s curator of fossil plants.
Allen says not only could tropical rain forest systems collapse, but drought in southern Europe and the United States would be "completely catastrophic for agriculture." Wealthy nations might maintain food supply, but not places like southern Africa. "A lot of people would have to leave, or a lot of people would die," Allen says.