Adapting to climate change may have been easier 13,500 years ago

Adapting to climate change may have been easier in the past, according to a new study.

Samuel Munoz, now a doctoral student at the University of Wisconsin-Madison, and geologist Konrad Gajewski at the University of Ottawa measured the effects of five major climate change events in North America.

They looked at samples of sedimentary pollen and charcoal collected between Maine and Pennsylvania.

This gave them a historical record of temperatures, vegetation patterns and fire history in the area, which was then matched with data from the Canadian Archaeological Radiocarbon Database, containing more than 35,000 radiocarbon dates.

The period they examined ranged from the time humans first settled the region 13,500 years ago to the first European-settled colonies 500 years ago.

The researchers compared the known changes in climate to the cultural time periods defined as Paleoindian, Archaic and Woodland.

Every change in the climate, they discovered, occurred at the same time as a change in the culture. The tools the natives used, the crops they grew, the animals they hunted all changed with the circumstances.

“Even the subgroups within the periods lined up with environmental changes,” Past Horizons quoted Gajewski as saying.

Some of the changes were abrupt, some more gradual, but largely ‘every cultural transition corresponds to a major transition in the climate and vegetation of the region’, observed the researchers.

When climate change altered food resources for pre-agricultural American Indians, they shifted strategy, and sometimes population size.

Similar climate changes are now happening in Alaska and the Yukon, where the present day indigenous people are still living.

Summers are getting drier and lightning-caused forest fires are getting more intense. The boreal forest, mostly spruce, is on the verge of a major transformation and will gradually be replaced by lodgepole pines. 

Besides changing the look of the forest, the transition will be good news for moose, which find lots to eat in deciduous forests, and bad news for caribou now living the area, which do not.

“People who are dependent on caribou will have to change," said Gajewski.

But they will find adaptation more difficult than the people of the past, according to Craig Gerlach of the Center for Cross Cultural Studies at the University of Alaska Fairbanks as modern indigenous people can no longer pick up and move or change their food sources as easily.

"Five hundred years, a thousand years ago people would have been able to respond to changes in distribution and abundance whether driven by natural cycles or by changes in the climate or weather," said Gerlach. "People are no longer as flexible because they live in permanent villages, so they can’t respond appropriately."

“In the past, people would have been able to respond to changes in distribution and abundance whether driven by natural cycles or by changes in the climate or weather,” said Gerlach. 

Human ingenuity being what it is, they may, of course, prevail without losing their culture, although it will probably not be easy.

The study is published in the Proceedings of the National Academy of Sciences.