Anthropocene Epoch, unofficial interval of geologic time, making up the third worldwide division of the Quaternary Period (2.6 million years ago to the present), characterized as the time in which the collective activities of human beings (Homo sapiens) began to substantially alter Earth’s surface, atmosphere, oceans, and systems of nutrient cycling. A growing group of scientists argue that the Anthropocene Epoch should follow the Holocene Epoch (11,700 years ago to the present) and begin in the year 1950. The name Anthropocene is derived from Greek and means the “recent age of man.” Although American biologist Eugene Stoermer coined the term in the late 1980s, Dutch chemist and Nobelist Paul Crutzen is largely credited with bringing public attention to it at a conference in 2000 as well as in a newsletter printed the same year. In 2008 British geologist Jan Zalasiewicz and his colleagues put forth the first proposal to adopt the Anthropocene Epoch as a formal geological interval. In 2016 the Anthropocene Working Group of the International Union of Geologic Sciences (IUGS) voted to recommend the Anthropocene as a formal geologic epoch at the 35th International Geological Congress. In order for this interval to be made official, it first must be adopted by the IUGS and the International Commission on Stratigraphy. On August 29, 2016, the Anthropocene Working Group recommended that the Anthropocene Epoch be made an official geologic unit. Changes in rock strata and the makeup of the fossils they contain are used to mark the boundaries between formal intervals of geologic time. Throughout Earth’s history, periods of upheaval characterized by mass extinctions, changes in sea level and ocean chemistry, and relatively rapid changes in prevailing climate patterns are captured in the layers of rock. Often these periods mark the end of one interval and the beginning of another. The formalization of the Anthropocene hinges on whether the effects of humans on Earth are substantial enough to eventually appear in rock strata. Most scientists agree that the collective influence of humans was small before the dawn of the Industrial Revolution during the middle of the 18th century; however, advancements in technology occurring since then have made it possible for humans to undertake widespread, systematic changes that affect several facets of the Earth system. At present, human beings have a profound influence over Earth’s surface, atmosphere, oceans, and biogeochemical nutrient cycling. By 2005, humans had converted nearly two-fifths of Earth’s land area for agriculture. (Cultivated land accounted for one-tenth of the land surface, whereas roughly three-tenths were used for pasture.) An additional one-tenth of Earth’s land area was given over to urban areas by this time. According to some estimates, humans have harvested or controlled roughly one-quarter to one-third of the biomass produced by the world’s terrestrial plants (net primary production) on a yearly basis since the 1990s. Such sweeping control over Earth’s plant production has been attributed in large part to the development of a method of industrial nitrogen fixation called the Haber-Bosch process, which was created in the early 1900s by German chemist Fritz Haber and later refined by German chemist Carl Bosch. The Haber-Bosch process synthesizes ammonia from atmospheric nitrogen and hydrogen under high temperatures and pressures for use in artificial fertilizers and munitions. The industrialization of this process increased the amount of usable nitrogen in the world by 150 percent, which has greatly enhanced crop yields and, along with other technological developments, facilitated the exponential rise in the world’s human population from about 1.6 billion–1.7 billion in 1900 to 7.4 billion by 2016.