A tale of two planets: The Anthropocene revisited
Is the Anthropocene recent? Defined solely by the accelerating impacts of an industrial society that threatens the future of both humanity and the biosphere?
A closer look at the history of human use of land yields a very different story. Recently in PNAS, IVM professor Peter Verburg and international collegues present a new global history of land use suggesting that human transformation of the terrestrial biosphere was already globally significant more than 3000 years ago.
The evidence, detailed in the paper, is of three kinds. First, historical predictions from a new spatial model of global land use history developed by coauthor Jed Kaplan (the KK10 model), were compared against an earlier model that has become the accepted reference for most global change scientists: the HYDE model of coauthor Kees Klein Goldewijk. Unlike prior global models of early land use, Kaplan’s model was derived from nonlinear empirical relationships observed between per capita land use and population density over the long term- relationships that agree with widely accepted theories of land use intensification in traditional smallholder agricultural systems. When these two models are compared (see figure), their differences are so striking that they might as well come from two different planets: one with ancient and extensive human use of land (KK10), one with land use changing mostly in recent centuries (HYDE).
To explore whether existing theories of land use intensification could explain land use change processes across the entire span of the Holocene, from the late Pleistocene up to the present day, we reviewed the extensions of intensification theory found in archaeology, environmental history, geography and other disciplines that study human/environment relationships. From this, it became clear that intensification theory could readily be broadened to include a wide range of adaptive practices and land use systems that have enabled increasing human population densities to drive increasingly productive and efficient use of the same land over time to support growing populations over the long term. Finally, we examined the evidence from archaeology, paleoecology and agricultural history to assess the plausibility of the two different models of early land use history.
The most plausible history of our planet is one of early transformation of the terrestrial biosphere by human use of land, with land use intensification processes playing a central role in regulating long-term changes in human-environmental relationships.
Ellis EC, Kaplan JO, Fuller DQ, Vavrus S, Klein Goldewijk K, Verburg PH. (2013). "Used planet: A global history." Proceedings of the National Academy of Sciences. http://dx.doi.org/10.1073/pnas.1217241110
Contact: Peter Verburg