LEICESTER, ENGLAND—An international group of scientists known as the Anthropocene Working Group argues the Earth entered a new geological epoch characterized by the spread of novel materials in the mid-twentieth century. These materials are measurable in geological strata and are different from the signals of the Holocene Epoch of the last 11,700 years. During the Holocene, humans gradually built urban settlements and increased food production while using water, mineral, and energy resources. The proposed Anthropocene Epoch, however, is marked by increased consumption and rapid environmental change brought on by a population surge. “Humans have long affected the environment, but recently there has been a rapid global spread of novel materials including aluminum, concrete, and plastics, which are leaving their mark in sediments. Fossil-fuel combustion has dispersed fly ash particles worldwide, pretty well coincident with the peak distribution of the ‘bomb spike’ of radionuclides generated by atmospheric testing of nuclear weapons,” Colin Waters of the British Geological Survey said in a University of Leicester press release. The Anthropocene Working Group will continue to gather evidence to define and characterize this proposed new epoch. To read about the archaeology of the Nuclear Age, go to "Dawn of a Thousand Suns."