At that time, global average temperatures were 3 or 4C higher than today's and 8C warmer at the poles. Reef corals suffered a major extinction while forests grew up to the northern edge of the Arctic Ocean, a region which is today bare tundra.In short, contra the Koch Bros., eXXXonMobil, Peabody Coal, et al, trying to tell us that "carbon dioxide is good," our genus, not just the particular species, Homo sapiens, will face a brave new world, indeed.
Oh, sure, atmospheric CO2 has been even higher, even much higher. And that was when dinosaurs and similar reptilians ruled the planet, facing the first shrewlike mammals.
And, even then, CO2 levels weren't changing nearly as rapidly. (Sidebar: While I'm not a "Frankenfooder," this "degree of change" issue is one thing I raise repeatedly against those who issue a blank check to the world of genetically modified organisms.)
What's it mean?
"We are creating a prehistoric climate in which human societies will face huge and potentially catastrophic risks," said Bob Ward, policy director at the Grantham Research Institute on Climate Change at the London School of Economics. "Only by urgently reducing global emissions will we be able to avoid the full consequences of turning back the climate clock by 3 million years."Unfortunately, fat chance, Bob.
We've likely got a 2 ppm per year change cooked in the books for 25 years or so, at a minimum.
In other words, onward to 450 by 2040.
And, unlike Peak Oil, where US technology mixed with the fungibility of crude means we might be no worse off, the US, with its favorable geographic location for industrialized agriculture, and its ever-growing dependence on air conditioning, is in special danger vis-a-vis many other countries.
But, not enough farmers and ranchers of the Midwest and Plains States will yet connect the dots, and those that do can't drown out the professionally funded deniers.