Dr. Erle Ellis is Associate Professor of Geography and Environmental Systems at the University of Maryland, Baltimore County, where he teaches Environmental Science, Landscape Ecology and Biogeochemistry. His research focuses on ecological processes in anthropogenic landscapes at local, regional and global scales, and their transformation by population growth and industrially-based technologies.
The Anthropocene defines Earth’s most recent geologic time period as being human-influenced, or anthropogenic, based on overwhelming global evidence that atmospheric, geologic, hydrologic, biospheric and other earth system processes are now altered by humans. The word combines the root “anthropo”, meaning “human” with the root “-cene”, the standard suffix for “epoch” in geologic time.
The Anthropocene is distinguished as a new period either after or within the “Holocene”, the current epoch, which began approximately 10,000 years ago (about 8000 BC) with the end of the last glacial period.
Origins of the term
Anthropocene is a new term, proposed in 2000 by Nobel Prize winning scientist Paul Crutzen. A similar term, “Anthrocene”, was coined by Andrew Revkin in his 1992 book ”Global Warming: Understanding the
Forecast”, but was not adopted by scientists. Crutzen noted that the term originated in 2000 at “a conference where someone said something about the Holocene. I suddenly thought this was wrong. The world has changed too much. So I said: ‘No, we are in the Anthropocene.’ I just made up the word on the spur of the moment. Everyone was shocked. But it seems to have stuck.” Crutzen then proceeded to use the term in print in 2000. In 2008, Zalasiewicz and colleagues published the first proposal for the formal adoption of the Anthropocene epoch by geologists, and this adoption is now pending.
Evidence for the Anthropocene
Geologic epochs are distinguished from one another based on geological observations, such as the composition of sediment layers and other tools of paleoclimatology. To justify the identification of a new Anthropocene epoch, it must therefore be demonstrated that evidence of anthropogenic global change is present at such a level that it can be distinguished using geologic indicators despite natural variability in these across the Holocene.
The most commonly cited and readily measured global change associated with humans is the rise of greenhouse gases, especially carbon dioxide and methane, around the beginning of the Industrial Revolution, together with the associated rise in global temperatures and sea level caused by this global warming. Other key indicators include massive global increases in soil erosion caused by land clearing and soil tillage for agriculture and massive extinctions of species caused by hunting and the widespread destruction of natural habitats.