Anthropocene: The Human Age. Monastersky, R. Nature, 519(7542):144–147, March, 2015.
doi  abstract   bibtex   
Momentum is building to establish a new geological epoch that recognizes humanity's impact on the planet. But there is fierce debate behind the scenes. [Excerpt] [...] Through mining activities alone, humans move more sediment than all the world's rivers combined. Homo sapiens has also warmed the planet, raised sea levels, eroded the ozone layer and acidified the oceans. [\n] Given the magnitude of these changes, many researchers propose that the Anthropocene represents a new division of geological time. The concept has gained traction, especially in the past few years – and not just among geoscientists. The word has been invoked by archaeologists, historians and even gender-studies researchers; several museums around the world have exhibited art inspired by the Anthropocene; and the media have heartily adopted the idea. '' Welcome to the Anthropocene,'' The Economist announced in 2011. [\n] The greeting was a tad premature. Although the term is trending, the Anthropocene is still an amorphous notion – an unofficial name that has yet to be accepted as part of the geological timescale. That may change soon. A committee of researchers is currently hashing out whether to codify the Anthropocene as a formal geological unit, and when to define its starting point. [\n] But critics worry that important arguments against the proposal have been drowned out by popular enthusiasm, driven in part by environmentally minded researchers who want to highlight how destructive humans have become. Some supporters of the Anthropocene idea have even been likened to zealots. '' There's a similarity to certain religious groups who are extremely keen on their religion – to the extent that they think everybody who doesn't practise their religion is some kind of barbarian,'' says one geologist who asked not to be named. [\n] The debate has shone a spotlight on the typically unnoticed process by which geologists carve up Earth's 4.5 billion years of history. Normally, decisions about the geological timescale are made solely on the basis of stratigraphy – the evidence contained in layers of rock, ocean sediments, ice cores and other geological deposits. But the issue of the Anthropocene '' is an order of magnitude more complicated than the stratigraphy'', says Jan Zalasiewicz, a geologist at the University of Leicester, UK, and the chair of the Anthropocene Working Group that is evaluating the issue for the International Commission on Stratigraphy (ICS). [...] [\n] When the Anthropocene Working Group started investigating, it compiled a much longer long list of the changes wrought by humans. Agriculture, construction and the damming of rivers is stripping away sediment at least ten times as fast as the natural forces of erosion. Along some coastlines, the flood of nutrients from fertilizers has created oxygen-poor 'dead zones', and the extra CO2 from fossil-fuel burning has acidified the surface waters of the ocean by 0.1 pH units. The fingerprint of humans is clear in global temperatures, the rate of species extinctions and the loss of Arctic ice. [\n] The group, which includes Crutzen, initially leaned towards his idea of choosing the Industrial Revolution as the beginning of the Anthropocene. But other options were on the table. [\n] Some researchers have argued for a starting time that coincides with an expansion of agriculture and livestock cultivation more than 5,000 years ago4, or a surge in mining more than 3,000 years ago (see 'Humans at the helm'). But neither the Industrial Revolution nor those earlier changes have left unambiguous geological signals of human activity that are synchronous around the globe (see 'Landscape architecture'). [\n] This week in Nature, two researchers propose that a potential marker for the start of the Anthropocene could be a noticeable drop in atmospheric CO2 concentrations between 1570 and 1620, which is recorded in ice cores (see page 171). They link this change to the deaths of some 50 million indigenous people in the Americas, triggered by the arrival of Europeans. In the aftermath, forests took over 65 million hectares of abandoned agricultural fields – a surge of regrowth that reduced global CO2. [\n] In the working group, Zalasiewicz and others have been talking increasingly about another option – using the geological marks left by the atomic age. Between 1945 and 1963, when the Limited Nuclear Test Ban Treaty took effect, nations conducted some 500 above-ground nuclear blasts. Debris from those explosions circled the globe and created an identifiable layer of radioactive elements in sediments. At the same time, humans were making geological impressions in a number of other ways – all part of what has been called the Great Acceleration of the modern world. Plastics started flooding the environment, along with aluminium, artificial fertilizers, concrete and leaded petrol, all of which have left signals in the sedimentary record. [...]
@article{monasterskyAnthropoceneHumanAge2015,
  title = {Anthropocene: The Human Age},
  author = {Monastersky, Richard},
  year = {2015},
  month = mar,
  volume = {519},
  pages = {144--147},
  issn = {0028-0836},
  doi = {10.1038/519144a},
  abstract = {Momentum is building to establish a new geological epoch that recognizes humanity's impact on the planet. But there is fierce debate behind the scenes.

[Excerpt] [...] Through mining activities alone, humans move more sediment than all the world's rivers combined. Homo sapiens has also warmed the planet, raised sea levels, eroded the ozone layer and acidified the oceans.

[\textbackslash n] Given the magnitude of these changes, many researchers propose that the Anthropocene represents a new division of geological time. The concept has gained traction, especially in the past few years -- and not just among geoscientists. The word has been invoked by archaeologists, historians and even gender-studies researchers; several museums around the world have exhibited art inspired by the Anthropocene; and the media have heartily adopted the idea. '' Welcome to the Anthropocene,'' The Economist announced in 2011.

[\textbackslash n] The greeting was a tad premature. Although the term is trending, the Anthropocene is still an amorphous notion -- an unofficial name that has yet to be accepted as part of the geological timescale. That may change soon. A committee of researchers is currently hashing out whether to codify the Anthropocene as a formal geological unit, and when to define its starting point.

[\textbackslash n] But critics worry that important arguments against the proposal have been drowned out by popular enthusiasm, driven in part by environmentally minded researchers who want to highlight how destructive humans have become. Some supporters of the Anthropocene idea have even been likened to zealots. '' There's a similarity to certain religious groups who are extremely keen on their religion -- to the extent that they think everybody who doesn't practise their religion is some kind of barbarian,'' says one geologist who asked not to be named.

[\textbackslash n] The debate has shone a spotlight on the typically unnoticed process by which geologists carve up Earth's 4.5 billion years of history. Normally, decisions about the geological timescale are made solely on the basis of stratigraphy -- the evidence contained in layers of rock, ocean sediments, ice cores and other geological deposits. But the issue of the Anthropocene '' is an order of magnitude more complicated than the stratigraphy'', says Jan Zalasiewicz, a geologist at the University of Leicester, UK, and the chair of the Anthropocene Working Group that is evaluating the issue for the International Commission on Stratigraphy (ICS). [...]

[\textbackslash n] When the Anthropocene Working Group started investigating, it compiled a much longer long list of the changes wrought by humans. Agriculture, construction and the damming of rivers is stripping away sediment at least ten times as fast as the natural forces of erosion. Along some coastlines, the flood of nutrients from fertilizers has created oxygen-poor 'dead zones', and the extra CO2 from fossil-fuel burning has acidified the surface waters of the ocean by 0.1 pH units. The fingerprint of humans is clear in global temperatures, the rate of species extinctions and the loss of Arctic ice.

[\textbackslash n] The group, which includes Crutzen, initially leaned towards his idea of choosing the Industrial Revolution as the beginning of the Anthropocene. But other options were on the table.

[\textbackslash n] Some researchers have argued for a starting time that coincides with an expansion of agriculture and livestock cultivation more than 5,000 years ago4, or a surge in mining more than 3,000 years ago (see 'Humans at the helm'). But neither the Industrial Revolution nor those earlier changes have left unambiguous geological signals of human activity that are synchronous around the globe (see 'Landscape architecture').

[\textbackslash n] This week in Nature, two researchers propose that a potential marker for the start of the Anthropocene could be a noticeable drop in atmospheric CO2 concentrations between 1570 and 1620, which is recorded in ice cores (see page 171). They link this change to the deaths of some 50 million indigenous people in the Americas, triggered by the arrival of Europeans. In the aftermath, forests took over 65 million hectares of abandoned agricultural fields -- a surge of regrowth that reduced global CO2.

[\textbackslash n] In the working group, Zalasiewicz and others have been talking increasingly about another option -- using the geological marks left by the atomic age. Between 1945 and 1963, when the Limited Nuclear Test Ban Treaty took effect, nations conducted some 500 above-ground nuclear blasts. Debris from those explosions circled the globe and created an identifiable layer of radioactive elements in sediments. At the same time, humans were making geological impressions in a number of other ways -- all part of what has been called the Great Acceleration of the modern world. Plastics started flooding the environment, along with aluminium, artificial fertilizers, concrete and leaded petrol, all of which have left signals in the sedimentary record. [...]},
  journal = {Nature},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-13547930,anthropic-feedback,anthropocene,anthropogenic-changes,anthropogenic-impacts,climate,ecology,evolution,featured-publication,long-distance-dispersal,species-distribution},
  lccn = {INRMM-MiD:c-13547930},
  number = {7542}
}
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