Starting dates

Starting dates of the Anthropocene

When has the Anthropocene begun?

Starting dates of the Anthropocene induced an extremely diverse discussion across academic disciplines, from the natural sciences to history, sociology and politics. This discussion centres on the questions of when the human impact on the Earth system, and especially on geological processes, started to be significant and fundamental to substantiate the definition of a new geological time unit that terminates or even replaces the Holocene. Originally, Paul Crutzen suggested the start of the Industrial Revolution, i.e. the invention of the steam engine in 1783, as a possible start date for the Anthropocene. Members of the stratigraphic Anthropocene Working Group suggested in a first paper the use of the world's first nuclear bomb explosion, on July 16th 1945 at Alamogordo, New Mexico, USA. This event spread globally a sequence of significant artificial radionuclides which may be used as the primary stratigraphic marker for the base of the Anthropocene. Later on, the working group introduced a potential and pragmatic base in the 1950s with the first appearance of plutonium 239/240 from radiogenic bomb test fallout. The mid-20th century placement is related to the 'Great Acceleration' concept, the exponential increase in rates of changes in various human-influenced Earth system trends leading to critical tipping points, the planetary boundaries, into a new state of the Earth system. Slightly earlier potential definitions and markers for the base of the Anthropocene include the rise of greenhouse gases during the Industrial Revolution and the Columbian Exchange, the widespread transfer of animals, culture, diseases, human populations, ideas, plants and technology between the Americas and the Old World.

This relatively young historic placement of the start date of the Anthropocene concurs with mainly archaeological and geo-ecological arguments about a long lasting, significant and steadily increasing human influence on the Earth since thousands of years, the Early Anthropocene hypothesis. Within such a gradual increasing influence, no real point of start can be defined, thus a transitional phase into the Anthropocene is favoured by some scientists. Major events in this Early Anthropocene provide diachronous steps in human cultural evolution and interaction with the Earth system such as the advent of agriculture or first widespread environmental pollution due to metal mining and smelting. However, these early event provide so far no synchronous Anthropocene starting date. -- Michael Wagreich

Experts: Michael Wagreich, Erich Draganits, Eva Horn, Marta Luciani