HUMAN RESPONSE TO HOLOCENE CLIMATE FLUCTUATIONS: HAVE WE BEEN HERE BEFORE?

Abstract

The central proposition of this project is that archaeology has relevance and utility for general contemporary society, rather than just for the select group of academics who have chosen it as a field of study. The National Historic Preservation Act (NHPA) ensures that federal actions taken on behalf of the public will take into account the potential impact those actions might have on archaeological resources. As such, the discipline has real consequences for the public in the form of public expenditures. Archaeological research is often labor intensive, time-consuming, and expensive, so it is reasonable to ask what public benefit will be realized as a result of those expenditures. This is certainly something that professional archaeologists working in the field of cultural resources management have wrestled with. Unlike the public benefit of other regulatory laws, such as those enforcing clean air and clean water standards, the public benefit of conducting archaeological research and protecting archaeological sites is not self-evident. However, recent contributions by archaeologists to paleoclimate studies have given the discipline a new currency, with the public benefit being insights into one of the most controversial and far-reaching issues of our time: climate change. Paleoclimate research has found that the Earth’s climate has undergone numerous oscillations during the current interglacial period (the Holocene). Until the modern era, these oscillations were, in all likelihood, caused by orbital forcing (eccentricity, axial tilt, and precession) working in conjunction with various feedback phenomena, such as volcanic emissions, surface reflectivity, atmospheric reflectivity, atmospheric chemistry, etc., with the net result being a somewhat predictable cycle of alternating cool and warm periods over the past 12,000 years. Archaeological research, augmented by historical documentation from Europe and Asia, has shown that these oscillations align with significant periods of culture change in both the Old and New Worlds. By comparing climate predictions for the future with the paleoclimate record and episodes of past culture change, this project offers the following qualified insights into what society might expect for the terminal 21st Century:The historic and archaeological records indicate the scale of climate events necessary to have a meaningful influence on human society is not very great. For the modern world, at-risk countries could face social collapse as a result of food stress brought on by increased aridification, while First World nations could have to deal with substantial population displacements from regions experiencing water shortages and an increased cost of living.By the end of the 21st Century, the predicted warming trajectory will probably push average global temperature past anything that has been experienced during the Holocene to date; there are no past conditions that are analogous to projected future conditions. The implication is that mankind should expect the need for significant cultural adaptation to future climate change.