Dating the Anthropocene: Towards an empirical global history of human transformation of the terrestrial biosphere

Abstract

Human use of land is a major cause of the global environmental changes that define the Anthropocene. Archaeological and paleoecological evidence confirm that human populations and their use of land transformed ecosystems at sites around the world by the late Pleistocene and historical models indicate this transformation may have reached globally significant levels more than 3000 years ago. Yet these data in themselves remain insufficient to conclusively date the emergence of land use as a global force transforming the biosphere, with plausible dates ranging from the late Pleistocene to AD 1800. Conclusive empirical dating of human transformation of the terrestrial biosphere will require unprecedented levels of investment in sustained interdisciplinary collaboration and the development of a geospatial cyberinfrastructure to collate and integrate the field observations of archaeologists, paleoecologists, paleoenvironmental scientists, environmental historians, geoscientists, geographers and other human and environmental scientists globally from the Pleistocene to the present. Existing field observations may yet prove insufficient in terms of their spatial and temporal coverage, but by assessing these observations within a spatially explicit statistically robust global framework, major observational gaps can be identified, stimulating data gathering in underrepresented regions and time periods. Like the Anthropocene itself, building scientific understanding of the human role in shaping the biosphere requires both sustained effort and leveraging the most powerful social systems and technologies ever developed on this planet.

Soil carbon debt of 12,000 years of human land use

“…Human population and economic growth has led to an exponential rise in use of soil resources. Roughly 50 million km 2 of soils are currently being managed to some degree by humans for food, fiber, and livestock production (4), leading to the declaration that we live on a "used planet" (5). The consequences of human domination of soil resources are far ranging (6,7): accelerated erosion, desertification, salinization, acidification, compaction, biodiversity loss, nutrient depletion, and loss of soil organic matter (SOM).…”

Ecology in an anthropogenic biosphere

“…Though the global extent and dynamics of this transformation remain poorly understood, hunter-gatherer societies used fire to clear land long before the emergence of agriculture, transforming wildlands into the open landscape mosaics of seminatural anthromes (Figs. 3B and 4C;Williams 2008, Ellis et al 2013a. With the rise of horticultural societies, the first cropland anthromes appear and then the scale, intensity, and sophistication of ecosystem engineering escalates from propagation and domestication to the sustained tillage, irrigation, manuring, and other practices required to support the ever-larger scales of agrarian societies and later, the first urban populations subsisting on trade and other exchange processes (Figs.…”

Archaeology in the age of the Anthropocene: A critical assessment of its scope and societal contributions

“…Leaving aside the question as to whether the ICS, who actually determine how and whether geological epochs can be named by scientists agree to formally recognize the Anthropocene as a new geological epoch (something they will not decide upon until 2016), opinion also seems to be shifting toward a two-phase definition of the Anthropocene. Namely, an early phase that began several thousands of years ago, although opinion differs on exactly how long ago (compare, for instance, Olofsson and Hickler 2008;Certini and Scalenghe 2011;Ellis et al 2013;Smith and Zeder 2013), initially at a fairly small scale but with impacts becoming far more significant by the start of the industrial era; and, a later, very rapid phase of accelerating and widespread impacts from ca. A.D. 1750 (Ruddiman 2013).…”