By Tamara Jager Stewart
Severe drought, mega fires, reservoirs evaporating, glaciers melting, sea levels rising, devastating hurricanes—these and other calamities are the consequences of climate change, which the British newspaper The Guardian proclaims is the biggest threat to humanity aside from nuclear war. The United Nations has released their latest Intergovernmental Panel on Climate Change (IPCC) report, and for the first time an archaeologist, Tim Kohler of Washington State University, served as a lead author of a chapter about how ancient people dealt with this problem. By documenting their responses to extreme weather over millennia, archaeology can inform us how humans adapted, or failed to adapt, to these challenges.
“Most archaeologists are not narrow specialists,” said Kohler. “We can’t be, because we are supposed to be thinking broadly about the causes for change in the distant past. So we have to know something about climates, economics, demography, political organization, and how people interact. Having to weigh those various sources of change in accounting for past social change ought to be useful for thinking about how global warming might affect current and future societies.”
Kohler works in the American Southwest, where he sees countless examples of past adaptations to climate variability since the last Ice Age around 12,000 years ago. Thirteenth century volcanic activity led to drops in global temperatures—referred to as the Little Ice Age—that affected all of North America. Severe droughts late in that century afflicted people in the Mississippian heartland and the Southwest. When a drought occurred in the Mesa Verde region of southwestern Colorado, Kohler said the residents built thousands of small, simple rock and dirt check dams that retained water and topsoil.