Abstract
Since Paul Crutzen introduced the term Anthropocene twenty-five years ago, it has become conflated with the concept of anthropogenic impact, which is globally diachronous. Crutzen introduced the term as a geological epoch to reflect the altered state of the Earth System, however, signifying an end to the Holocene Epoch whose relative stability fostered the evolution of human culture. The culmination of a fifteen-year effort to formally define the Anthropocene as an epoch was the proposal of a “golden spike” in sediments from a small Canadian lake in a conservation area near Toronto. Several episodes of anthropogenic impact are recorded in its annually laminated sediments in addition to the signature of the Great Acceleration of the mid-twentieth century. Evidence of the rapid increase in fossil fuel consumption, industrial production and human population can be precisely dated in the varved sediment of this unique lake, and the sharp increase in radionuclides with the introduction of the H-bomb allows the use of the anthropogenic isotope plutonium-239 as a globally synchronous marker of the base of the proposed Anthropocene epoch. The International Union of Geological Sciences rejected adding the Anthropocene to the Geological Time Scale, rejecting the idea that human activities have shifted the planetary system away from Holocene norms. Arguably, ignoring evidence that Anthropos has altered how the atmosphere, biosphere, and other components of the Earth System interact is at least as political as adding the Anthropocene to the Geologic Time Scale, impeding scientific communication efforts to deal with the climate crisis.