"We have markers for various important events in hominid history -- the origin of new species, the development of new tools," said Matt Grove, a professor of archaeology, classics and Egyptology at the University of Liverpool who has worked with Potts to model variability selection. "If those events line up with what the climate record tells us were the periods of instability, that would seem to support Rick's theory. And, in general, they do."
New and ominous test on the horizon
The origin of every hominid genus, including our own, appears to fall within one or another of these windows of climatic variability, he said.
"What we see is that it isn't just the origin of new [hominid] species that emerge during these periods, but also new ways of life, of living and interacting with the environment," Potts said.
The big irony, Grove explained, is that capacity to interact with our environment has put us back on a trajectory of climate instability. And this time, pumped by man-made greenhouse gases, global warming is happening much faster than previous shifts.
With the dawn of agriculture 10,000 years ago, humans embarked on a new experiment -- rather than adapting to our environment, we began adapting our environment to meet our needs, slashing and burning forests to create room for agriculture. That, in turn, allowed more leisure time, larger societies and a freer exchange of information. As cultural and technological knowledge improved, we were able to harness the energy of other animals and, in time, harness the dramatic power of fossil fuels as well.
Several times throughout human history, periods of climate instability sent shock waves through established empires, such as the Akkadian Empire of Mesopotamia or the Bronze Age empires of the Mediterranean (ClimateWire, Aug. 16). Each time, though, the species bounced back, more successful and adaptive than ever.
Now, with planetary warming occurring at a breakneck pace, human adaptability is likely to face its biggest test, Grove thinks.
"We've been dealing with climate change since we got here on Earth," he explained. "The problem, though, is that it's happening now over such a short time scale. And that makes it very hard to predict whether or not we'll be able to respond, or at what cost."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500