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Anthropocene

Anthropocene

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Encyclopedia
The Anthropocene is a recent and informal geologic chronological
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

 term that serves to mark the evidence and extent of human activities that have had a significant global impact on the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

's ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

s. The term was coined by ecologist Eugene Stoermer but has been widely popularized by the Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

-winning atmospheric chemist
Atmospheric chemistry
Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and...

 Paul Crutzen, who regards the influence of human behavior on the Earth's atmosphere in recent centuries as so significant as to constitute a new geological era for its lithosphere
Lithosphere
The lithosphere is the rigid outermost shell of a rocky planet. On Earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.- Earth's lithosphere :...

.

In 2008 a proposal was presented to the Stratigraphy Commission of the Geological Society of London
Geological Society of London
The Geological Society of London is a learned society based in the United Kingdom with the aim of "investigating the mineral structure of the Earth"...

 to make the Anthropocene a formal unit of geological time. A large majority of that Stratigraphy Commission decided the proposal had merit and should therefore be examined further. Steps are being taken by independent working groups of scientists from various geological societies to determine if the Anthropocene will be formally accepted into the Geological Time Scale
Geologic time scale
The geologic time scale provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth...

.

Many scientists are now using the term and the Geological Society of America
Geological Society of America
The Geological Society of America is a nonprofit organization dedicated to the advancement of the geosciences. The society was founded in New York in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Proctor and Edward Orton and has been headquartered at 3300 Penrose...

 titled its 2011 annual meeting: Archean
Archean
The Archean , also spelled Archeozoic or Archæozoic) is a geologic eon before the Paleoproterozoic Era of the Proterozoic Eon, before 2.5 Ga ago. Instead of being based on stratigraphy, this date is defined chronometrically...

 to Anthropocene: The past is the key to the future
. The Anthropocene has no precise start date, but based on atmospheric evidence may be considered to start with the Industrial Revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...

 (late 18th century). Other scientists link it to earlier events, such as the rise of agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

. Evidence of relative human impact such as the growing human influence on land use, ecosystems, biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 and species extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 is controversial, some scientists believe the human impact has significantly changed (or halted) the growth of biodiversity. The Anthropocene may have begun as early as 14,000 to 15,000 years before present
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...

, based on lithospheric evidence; this has led other scientists to suggest that "the onset of the Anthropocene should be extended back many thousand years"; this would be closely synchronous with the current term, Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

.

Etymology


The ecologist Eugene Stoermer originally coined the term Anthropocene by analogy
Analogy
Analogy is a cognitive process of transferring information or meaning from a particular subject to another particular subject , and a linguistic expression corresponding to such a process...

 with the word "Holocene". Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

-winning scientist Paul Crutzen subsequently popularized the usage.

The term has Greek roots: anthropo- meaning "human" and -cene meaning "new". Crutzen has explained, "I was at a conference where someone said something about the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

. 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 first used it in print in a 2000 newsletter of the International Geosphere-Biosphere Programme
International Geosphere-Biosphere Programme
The International Geosphere-Biosphere Programme is a research programme that studies the phenomenon of global change.The International Council of Scientific Unions, a coordinating body of national science organizations, launched IGBP in 1986...

 (IGBP), No.41. In 2008, Zalasiewicz suggested in GSA Today that an anthropocene epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

 is now appropriate.

As early as 1873, the Italian geologist Antonio Stoppani
Antonio Stoppani
Antonio Stoppani was an Italian geologist and palaeontologist. He died in 1891 aged 67Born in Lecco, he became professor of geology in the Royal Technical Institute of Milan, and was distinguished for his researches on the Triassic and Liassic formations of northern Italy.Among his works...

 acknowledged the increasing power and impact of humanity on the Earth's systems and referred to the 'anthropozoic era'. A similar term, Homogenocene (from old Greek: homo-, same geno-, kind, kainos-, new and -cene, period) was first used by Michael Samways in his editorial article in the Journal of Insect Conservation (1999) titled, "Translocating fauna to foreign lands: here comes the Homogenocene". Samways used the term to define our current geological epoch, in which biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 is diminishing and ecosystems around the globe become more similar to one another. The term was used by John L. Curnutt in 2000 in Ecology, in a short list titled "A Guide to the Homogenocene."
Curnutt was reviewing Alien species in North America and Hawaii: impacts on natural ecosystems by George Cox. Andrew Revkin
Andrew Revkin
Andrew C. Revkin is a journalist and author who has spent a quarter of a century covering subjects ranging from the assault on the Amazon to the Asian tsunami, from the troubled relationship of science and politics to climate change at the North Pole. From 1995 through 2009, he covered the...

 coined the term Anthrocene in his book Global Warming: Understanding the Forecast (1992), 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 evolved into the Anthropocene, which is generally regarded as being a more suitable technical term.

Definition of epoch


While much of the environmental change occurring on Earth is a direct consequence of the industrial revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...

, William Ruddiman
William Ruddiman
William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the University of Virginia. Ruddiman earned an undergraduate degree in geology in 1964 at Williams College, and a Ph.D. in marine geology from Columbia University in 1969. Ruddiman worked at the US Naval Oceanographic Office...

 has argued that the Anthropocene began approximately 8,000 years ago with the growth of farming. At this point, humans were dispersed across all of the continents (bar Antarctica), and the Neolithic Revolution
Neolithic Revolution
The Neolithic Revolution was the first agricultural revolution. It was the transition from hunting and gathering to agriculture and settlement. Archaeological data indicates that various forms of plants and animal domestication evolved independently in 6 separate locations worldwide circa...

 was ongoing. During this period, humans developed agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

 and animal husbandry
Animal husbandry
Animal husbandry is the agricultural practice of breeding and raising livestock.- History :Animal husbandry has been practiced for thousands of years, since the first domestication of animals....

 to supplement or replace hunter-gatherer
Hunter-gatherer
A hunter-gatherer or forage society is one in which most or all food is obtained from wild plants and animals, in contrast to agricultural societies which rely mainly on domesticated species. Hunting and gathering was the ancestral subsistence mode of Homo, and all modern humans were...

 subsistence. Such innovations were followed by a wave of extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

s, beginning with large mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s and land bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s. This wave was driven by both the direct activity of humans (e.g. hunting) and the indirect consequences of land-use change for agriculture.

This period (10,000 years to present) is usually referred to as the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

 by geologists. For the majority of the Holocene, 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 already occurring during this period.

In terms of trace elements, there are distinct signatures left by modern societies. For example, in the Upper Fremont Glacier
Upper Fremont Glacier
Upper Fremont Glacier is located in the Fitzpatrick Wilderness of Shoshone National Forest in the U.S. state of Wyoming. This Wind River Range glacier is associated with the largest grouping of glaciers in the U.S. Rocky Mountains and lies on the north slope of Fremont Peak, the third tallest...

, there is a layer of chlorine from 1960s atomic weapon testing programs present in ice cores, as well as a layer of mercury associated with coal plants in the 1980s.

Nature of human effects



Biodiversity


Many species have gone extinct due to human impact. Most experts agree that human beings have accelerated the rate of species extinction, though the exact rate is controversial, perhaps 100 to 1000 times the normal background rate of extinction. In 2010 a study published in Nature found that "marine phytoplankton — the vast range of tiny algae species accounting for roughly half of Earth's total photosynthetic biomass - have declined substantially in the world's oceans over the past century. Since 1950 alone, algal biomass decreased by around 40%, probably in response to ocean warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 - and the decline has gathered pace in recent years. Some authors have postulated that without human interference the biodiversity of this planet would continue to grow at an exponential rate.

Climate


One obvious geological signal of human activity is increasing atmospheric
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 (CO2) content. During the glacial-interglacial
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

 cycles of the past million years, natural processes have varied CO2 by approximately 100 ppm (from 180 ppm to 280 ppm). As of 2011, anthropogenic net emissions of CO2 have increased its atmospheric concentration by a comparable amount from 280 ppm (Holocene or pre-industrial "equilibrium") to about 390 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
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...

 of fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...

s such as coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

, oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

, although smaller fractions are the result of cement
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

 production and land-use changes (e.g. deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....

).

Anthropocene temporal limit


Arguing the early Anthropocene hypothesis, William Ruddiman
William Ruddiman
William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the University of Virginia. Ruddiman earned an undergraduate degree in geology in 1964 at Williams College, and a Ph.D. in marine geology from Columbia University in 1969. Ruddiman worked at the US Naval Oceanographic Office...

 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. 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. Furthermore, the argument that "something" is needed to explain the differences in the Holocene is challenged by more recent research showing that all interglacials differ.

However, the fact remains that 8,000 years ago the planet sustained a few million people and was still fundamentally pristine, hence the early Anthropocene hypothesis does not account for a substantial human footprint on Earth. On the other hand, also the Industrial Revolution proposed by Crutzen does not seem to be the most suitable start of Anthropocene
Anthropocene
The Anthropocene is a recent and informal geologic chronological term that serves to mark the evidence and extent of human activities that have had a significant global impact on the Earth's ecosystems...

. In fact, although it is unquestionable that the Industrial Revolution ushered in an unprecedented global human impact on the planet, much of Earth’s landscape had been already profoundly modified by human activities. Anthropocene beginning should hence be anticipated to the moment when humankind has joined with the other environmental forces in shaping the planet. In doing so, it is difficult, perhaps even unrealistic, to identify a Year Zero of the Anthropocene. In fact, the human impact on Earth has grown progressively, with few substantial slowdowns. However, a plausible starting point of the Anthropocene could be at c. 2,000 BP, which roughly coincides with the start of the final phase of Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

, the Subatlantic.

At this time, the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 encompassed large portions of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, the Middle East and North Africa, in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 the classical dynasties were flowering, the Middle kingdoms of India had already the largest economy of the ancient and medieval world, the Napata/Meroitic kingdom extended over the current Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

 and Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

, the Olmec
Olmec
The Olmec were the first major Pre-Columbian civilization in Mexico. They lived in the tropical lowlands of south-central Mexico, in the modern-day states of Veracruz and Tabasco....

s controlled central Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 and Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

, and the pre-Incan Chavín people managed large areas of northern Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

. Although often apart from each other and intermixed with buffering ecosystems, the areas directly impacted by these civilizations and others were large. Additionally, some activities, such mining, implied much more widespread perturbation of natural conditions.

Anthropocene marker


A marker that accounts for a substantial global impact of humans on the total environment, comparable in scale to those associated with significant perturbations of the geological past, is needed in place of minor changes in atmosphere composition.

A useful candidate for this purpose is the pedosphere
Pedosphere
The pedosphere is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The sum total of all the organisms, soils, water and air is termed as the "pedosphere"...

, which can retain information of its climatic and geochemical history with features lasting for centuries or millennia. Human activity is now firmly established as the sixth factor of soil formation. It affects pedogenesis either directly, by, for example, land levelling, trenching and embankment building for various purposes, organic matter enrichment from additions of manure or other waste, organic matter impoverishment due to continued cultivation, compaction from overgrazing or, indirectly, by drift of eroded materials or pollutants. Anthropogenic soils are soils markedly affected by human activities, such as repeated ploughing, the addition of fertilizers, contamination, sealing, or enrichment with artefacts (in the World Reference Base for Soil Resources
World Reference Base for Soil Resources
The World Reference Base for Soil Resources is the international standard taxonomic soil classification system endorsed by the International Union of Soil Sciences . It was developed by an international collaboration coordinated by the International Soil Reference and Information Centre and...

 they are classified as Anthrosols
Anthrosols
An Anthrosol in the FAO World Reference Base for Soil Resources is a type of soil that has been formed or heavily modified due to long-term human activity, such as from irrigation, addition of organic waste or wet-field cultivation used to create paddy fields....

 and Technosols
Technosols
A Technosol in the FAO World Reference Base for Soil Resources is a new type of soil that combines soils whose properties and pedogenesis are dominated by their technical origin...

). They are recalcitrant repositories of artefacts and properties that testify to the dominance of the human impact, and hence appear to be reliable markers for the Anthropocene. Some anthropogenic soils should be hence viewed as the ‘golden spikes’ of geologists (Global Boundary Stratotype Section and Point
Global Boundary Stratotype Section and Point
A Global Boundary Stratotype Section and Point, abbreviated GSSP, is an internationally agreed upon stratigraphic section which serves as the reference section for a particular boundary on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on...

), which are locations where there are strata successions with clear evidences of a worldwide event, including the appearance of distinctive fossils.

See also

  • Anthropocentrism
    Anthropocentrism
    Anthropocentrism describes the tendency for human beings to regard themselves as the central and most significant entities in the universe, or the assessment of reality through an exclusively human perspective....

  • Anthropogenic biomes
    Anthropogenic biomes
    Anthropogenic biomes, also known as anthromes or human biomes, describe the terrestrial biosphere in its contemporary, human-altered form using global ecosystem units defined by global patterns of sustained direct human interaction with ecosystems....

  • Ecocriticism
    Ecocriticism
    Ecocriticism is the study of literature and environment from an interdisciplinary point of view where all sciences come together to analyze the environment and brainstorm possible solutions for the correction of the contemporary environmental situation...

  • Effects of global warming
    Effects of global warming
    This article is about the effects of global warming and climate change. The effects, or impacts, of climate change may be physical, ecological, social or economic. Evidence of observed climate change includes the instrumental temperature record, rising sea levels, and decreased snow cover in the...

  • Geoengineering
    Geoengineering
    The concept of Geoengineering refers to the deliberate large-scale engineering and manipulation of the planetary environment to combat or counteract anthropogenic changes in atmospheric chemistry The Intergovernmental Panel on Climate Change concluded in 2007 that geoengineering options, such...

  • Holocene extinction

External links