In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives.

In this study, we present a transparent and reproducible approach to model agricultural production with respect to environmental characteristics and available labour. Our research focuses on the city of Pergamon and its surroundings, with an emphasis on the transition between the Hellenistic and Roman Imperial Period, where widespread demographic changes took place. We investigated the degree of local self-sufficiency using different concepts of a city’s complementary region. Using simple topographic derivatives, we derive a measure of environmental suitability that we translate into a carrying capacity index. Our results show that workforce was not a limiting factor for local self-sufficiency. However, environmental carrying capacity may have been limiting in a scenario with a large population. An active investment into the environment, e.g., by the construction of terraces, could have helped to increase the degree of self-sufficiency. Future research should investigate the level of resilience of such a coupled socio-ecological system in relation to environmental and socio-cultural dynamics.

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