To?understand earthquakes in Oklahoma, the Earth¡¯s sixth mass extinction, or the?rapid melting of the?Greenland Ice Sheet, we need the Anthropocene¡ªan epoch that acknowledges?humans as a global, geologic force. The Holocene, a?cozier geologic epoch that began 11,700 years ago with climatic warming (giving?us conditions that, among other things, led to farming),?doesn¡¯t cut it anymore.?The Holocene is outdated because it cannot explain the recent changes to the?planet: the now 400 parts per million of carbon dioxide in the atmosphere from?burning fossil?fuels, the radioactive elements present in the Earth¡¯s strata?from detonating nuclear weapons, or that one in five species in large?ecosystems is considered invasive. Humans caused?nearly all of the?907 earthquakes?in Oklahoma in 2015 as a result of the extraction process for oil and gas, part?of which involves injecting saltwater, a byproduct, into rock layers.?The?Anthropocene?is defined by a combination of large-scale human impacts and gives us a concept?that provides us with a sense of both our power as well as responsibility.

In?2016, the Anthropocene Working Group, made of 35 individuals, mostly?scientists, voted that the?Anthropocene should be formalized. This?means a proposal should be taken to the?overlords of geologic epochs,?the?International Commission on Stratigraphy, which will decide on whether to?formally adopt the Anthropocene into the official geological time scale.

Any?epoch needs a starting point, and the Anthropocene Working Group?favors a mid-20th?century start date, which corresponds to the?advent of nuclear technology and a global reach of?industrialization, but it?won¡¯t be that simple. Two geologists, one of whom is the Chair of the?International Commission on Stratigraphy,?pointed out that?units of geologic time?are not defined only by their start date, but also by?their content.?They argue that the Anthropocene is more a?prediction about what could appear in the future rather than what is currently?here?because, in geologic terms, it is ¡°difficult to distinguish the upper few?centimeters of sediment from the underlying Holocene.¡±?At the same time that hardcore geologists are pushing?back?against formalizing the Anthropocene, a recent article in?Nature?argued that social scientists should be?involved helping determine?the start-date of the Anthropocene. Social scientists¡¯?involvement in?delineating the geologic time scale would be unprecedented, but then again, so?is this new human-led era.

Whether?the geologic experts anoint it as an official epoch, enough of society has?already decided the Anthropocene is here. Humans are a planetary force.?Not since cyanobacteria has a?single?taxonomic group been so in charge. Humans have proven we are capable of seismic?influence, of depleting the ozone layer, of changing the biology of every?continent, but not, at least so?far, that we are capable of living on any other?planet.?The?more interesting questions may not be about whether the Anthropocene exists or when it began, but about?whether we are prepared for this kind of control.