Anthropocene: Shifting Paradigms in Geoscience, Philosophy, History and Geopolitics

Abstract:

The concept of the Anthropocene has created a profound paradigm shift within the scientific community that we argue will create equally important changes in philosophy, history and politics. There is general scientific agreement that human activity has been a geologically recent, yet profound, influence on the Earth System. The magnitude, variety and longevity of human-induced changes, to the lithosphere, hydrosphere, cryosphere, biosphere and atmosphere suggests that we should refer to the present, not as within the Holocene Epoch (as it is currently formally referred to), but instead as within the Anthropocene Epoch. Discussion is now centred on defining the start of the epoch using the fundamental principles of stratigraphy. These must include (i) a near permanent change to the Earth system that sets it on to a new trajectory and (ii) global changes to the Earth system recorded in a number of stratigraphic deposits worldwide to provide a correlative boundary event or marker called a Global Stratotype Section & Point (GSSP) or ‘golden spike’. Using this framework we conclude that just two time-periods are likely adhere to the criteria. These are 1) the irreversible cross-ocean exchange of species alongside the globally synchronous coolest part of the Little Ice Age in the 17^th century, marked by the 1610 minima of CO₂ (Orbis Spike), and 2) the accelerating atmospheric, oceanic and terrestrial changes in the second half of the 20^th century, referred to as the Great Acceleration and conveniently marked by the 1964 peak radionuclide fallout (Bomb Spike). We seek to clear up misconceptions and misunderstandings about geological criteria and relevant evidence that have crept into the literature. We also argue that there are multiple definitions of the Anthropocene and even if a formal definition of the Anthropocene Epoch is agreed by geoscientists, this would in no way invalidate other definitions or uses. It is the utility and wide appeal that makes the Anthropocene such an important concept.