Use of this concept as an official geological concept gained new support in early 2008, with publication of two new papers supporting this idea.
This period (10,000 years to present) is usually referred to as the Holocene by geologists, and for the majority of it human populations were relatively low and their activities considerably muted relative to that of the last few centuries. Nonetheless, many of the processes currently altering the Earth's environment were still taking place during this period.
One obvious geological signal of human activity is increasing atmospheric carbon dioxide (CO2) content. During the glacial-interglacial cycles of the past million years, natural processes have varied CO2 by approximately 100 ppm (from 180 ppm to 280 ppm). As of 2006, anthropogenic net emissions of CO2 have increased its atmospheric concentration by a comparable amount from 280 ppm (Holocene or pre-industrial "equilibrium") to more than 383 ppm. This signal in the Earth's climate system is especially significant because it is occurring much faster, and to an enormously greater extent, than previous, similar changes. Most of this increase is due to the combustion of fossil fuels such as coal, oil and gas, although smaller fractions are the result of cement production and land-use changes (e.g. deforestation).
William Ruddiman claims that the anthropocene as defined by significant human impact on greenhouse gas emissions began not in the industrial era, but 8,000 years ago, as ancient farmers cleared forests to grow crops, the early anthropocene hypothesis. Ruddiman's work has in turn been challenged on the grounds that comparison with an earlier interglaciation ("Stage 11", around 400,000 years ago) suggest that 16,000 more years must elapse before the current Holocene interglaciation comes to an end, and that thus the early anthropogenic hypothesis is invalid. But Ruddiman argues that this results from an invalid alignment of recent insolation maxima with insolation minima from the past, among other irregularities which invalidate the criticism.
A similar term was apparently coined by Andrew Revkin in his 1992 book Global Warming: Understanding the Forecast, in which he wrote:
We are entering an age that might someday be referred to as, say, the Anthrocene. After all, it is a geological age of our own making.
The word Anthropocene is generally regarded as being a more suitable technical term.
L'Etre humain et la connaissance naturelle qu'il a de Dieu: Essai sur la structure anthropo-theologique fondamentale de la revelation chretienne dans la pensee du P. Henri de Lubac.(SHORTER NOTICES)(Book Review)
Jun 01, 2005; L'ETRE HUMAIN ET LA CONNAISSANCE NATURELLE QU'IL A DE DIEU: ESSAI SUR LA STRUCTURE anthropo-THEOLOGIQUE FONDAMENTALE DE LA...