Presenter
Jan Zalasiewicz
Emeritus Professor of Palaeobiology
University of Leicester, UK
Description
In 2000, the atmospheric chemist and Nobel laureate Paul Crutzen proposed the relatively stable conditions of the Holocene had ended, and that we now live in the Anthropocene Epoch, marked by overwhelming human impact on natural systems. Since, 2009, the Anthropocene Working Group of the International Commission on Stratigraphy has been gathering evidence on potential formalization of the Anthropocene in the Geological Time Scale. A wide, distinctive and long-lasting array of lithostratigraphic, chemostratigraphic and biostratigraphic signals has been recognized, and Anthropocene strata may be characterized by such lithostratigraphic signals as widespread to near-ubiquitous plastics and fuel ash particulates, chemostratigraphic signals such as sharp changes to carbon and nitrogen isotope ratios and a globally distributed ‘bomb spike’ of artificial radionuclides, and biostratigraphic signals such as a rise in fossilizeable invasive species. The most pronounced change (and hence optimal position for the base of the Anthropocene) aligns with the ‘Great Acceleration’ of population, industrialization and globalization in the mid-20th century. Candidate stratotypes are currently being studied, and one will be selected as basis for a forthcoming proposal for formalizing the Anthropocene. The Anthropocene concept has generated controversy, though, and the success of this proposal is not guaranteed.
