Anthropogenic burning and the Anthropocene in late-Holocene California

This paper examines the hypothesis that human landscape modifications involving early agriculture contributed to greenhouse gas emissions in preindustrial times, a proposal that has significant implications for the timing of the Anthropocene era. In synthesizing recent papers that both advocate and challenge this hypothesis, we identify a major bias in the ongoing debate, which focuses on the land clearance practices of agrarian people, with insufficient consideration of a diverse range of hunter-gatherer societies who regularly utilized landscape-scale burning for various purposes. Employing California as a case study, we examine how the exclusion of hunter-gatherers from this debate may have shortchanged estimates of human biomass burning in preindustrial times. We also suggest that human population size may be a poor proxy for the degree of land clearance and anthropogenic burning, and we describe how previous approaches to these questions may have underplayed the importance of variation in the timing and magnitude of depopulation in different regions of the Americas.