Sunday, 19 October 2014

Climate change: Entering the Anthropocene

Earlier this week, the 'Working Group on the Anthropocene' met in Berlin:

ICS Subcommission on Quaternary Stratigraphy

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What is the 'Anthropocene'? - current definition and status

  • The 'Anthropocene' is a term widely used since its coining by Paul Crutzen and Eugene Stoermer in 2000 to denote the present time interval, in which many geologically significant conditions and processes are profoundly altered by human activities. These include changes in: erosion and sediment transport associated with a variety of anthropogenic processes, including colonisation, agriculture, urbanisation and global warming. the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements such as carbon, nitrogen, phosphorus and various metals. environmental conditions generated by these perturbations; these include global warming, ocean acidification and spreading oceanic 'dead zones'. the biosphere both on land and in the sea, as a result of habitat loss, predation, species invasions and the physical and chemical changes noted above.
  • The 'Anthropocene' is not a formally defined geological unit within the Geological Time Scale. A proposal to formalise the 'Anthropocene' is being developed by the 'Anthropocene' Working Group for consideration by the International Commission on Stratigraphy, with a current target date of 2016. Care should be taken to distinguish the concept of an 'Anthropocene' from the previously used termAnthropogene (cf. below**).
  • The 'Anthropocene' is currently being considered by the Working Group as a potential geological epoch, i.e. at the same hierarchical level as the Pleistocene and Holocene epochs, with the implication that it is within the Quaternary Period, but that the Holocene has terminated. It might, alternatively, also be considered at a lower (Age) hierarchical level; that would imply it is a subdivision of the ongoing Holocene Epoch.
  • Broadly, to be accepted as a formal term the 'Anthropocene' needs to be (a) scientifically justified (i.e. the 'geological signal' currently being produced in strata now forming must be sufficiently large, clear and distinctive) and (b) useful as a formal term to the scientific community. In terms of (b), the currently informal term 'Anthropocene' has already proven to be very useful to the global change research community and thus will continue to be used, but it remains to be determined whether formalisation within the Geological Time Scale would make it more useful or broaden its usefulness to other scientific communities, such as the geological community.
  • The beginning of the 'Anthropocene' is most generally considered to be at c. 1800 CE, around the beginning of the Industrial Revolution in Europe (Crutzen's original suggestion); other potential candidates for time boundaries have been suggested, at both earlier dates (within or even before the Holocene) or later (e.g. at the start of the nuclear age). A formal 'Anthropocene' might be defined either with reference to a particular point within a stratal section, that is, a Global Stratigraphic Section and Point (GSSP), colloquially known as a 'golden spike; or, by a designated time boundary (a Global Standard Stratigraphic Age).
  • The 'Anthropocene' has emerged as a popular scientific term used by scientists, the scientifically engaged public and the media to designate the period of Earth's history during which humans have a decisive influence on the state, dynamics and future of the Earth system. It is widely agreed that the Earth is currently in this state.

Subcomission on Quaternary Stratigraphy, ICS » Working Groups

This is from Thursday's Independent:

Anthropocene: We might be about to move from the Holocene to a new epoch

Experts meet to discuss humanity's devastating effect on our planet

CHRISTOPHER HOOTON  Thursday 16 October 2014

After 11,700 years, the Holocene epoch may be coming to an end, with a group of geologists, climate scientists and ecologists meeting in Berlin this week to decide whether humanity's impact on the planet has been big enough to deserve a new time period: the Anthropocene.

The term, coined in the 1980s by ecologist Eugene F. Stoermer, takes its prefix from the Ancient Greek word for human because its proponents believe the influence of humanity on the Earth's atmosphere and crust in the last few centuries is so significant as to constitute a new geological epoch.

The Anthropocene Working Group assembles in Berlin on Friday, an interdisciplinary body of scientists and humanists working under the umbrella of the International Commission on Stratigraphy and "tasked with developing a proposal for the formal ratification of the Anthropocene as an official unit amending the Geological Time Scale".

The AWG will examine the shift in the biophysical conditions of the Earth humans have brought about (Picture: Getty)

The 30-strong group, which includes a lawyer, has outlined two key questions which it will address during deliberations at the Haus der Kulturen der Welt:

"How does the recent cognition of the immense quantitative shift in the biophysical conditions of the Earth affect both scientific research and a political response to these changes?" and "Does the Anthropocene also pose a profound qualitative shift, a paradigm shift for the ways in which science, politics, and law advance accordingly?"

Following the Pleistocene, we have for the last 11,700 years lived in the Holocene epoch, which is characterised by the warmer and wetter conditions that came after the end of the last ice age and has seen humans establish new territories and the Earth's population soar.

Experts aim to "develop a proposal for the formal ratification of the Anthropocene as an official unit amending the Geological Time Scale" (Félix Pharand-Deschênes/Globaïa)

Many scientists are happy with the Holocene as a term, but after Nobel Prize-winning atmospheric chemist popularised the "Anthropocene" at the turn of the millennium it refuses to go away and the ICS has deemed it in need of serious debate.

Based around a series of presentations by members of the AWG and statements from invited speakers from the humanities, the social sciences, and political fields, the forum will "discuss both the extraordinary changes to the Earth system as well as its consequences in setting new agendas for governing, researching, and disseminating crucial knowledge."
In pictures: Changing climate around the world1 of 15

Greenland: Calved icebergs from the nearby Twin Glaciers are seen floating on the water in Qaqortoq, Greenland: Joe Raedle/Getty Images

The group has given itself until 2016 to come up with a proposal to submit to the ISC, which ultimately determines what time period we live in - this might seem like a long way away, but when you consider the earliest epoch, the Paleozoic, began approximately 541 to 252 million years ago, it's just a speck in the Earth's history.

Anthropocene: We might be about to move from the Holocene to a new epoch - Science - News - The Independent

And this is from the NewYork Times from a participant in that Berlin meeting:

Does the Anthropocene, the Age of Humans, Deserve a Golden Spike?



Many boundaries in geological history are demarcated physically with a golden spike in a particular rock layer, as here near Pueblo, Colo. (GSSP is the acronym for Global Stratotype Section and Point .)Credit Brad Sageman, Northwestern University

BERLIN — I just participated in the first face-to-face meeting of the Anthropocene Working Group , a subset of a branch of the International Commission on Stratigraphy examining whether humanity’s growth spurt (in both numbers and resource appetites ) has caused sufficient change to Earth systems to leave a discernible trace in layered rocks that will build and endure far into the future.

Here’s another way to frame the question: Have we left the Holocene Epoch — the warm interval since the end of the last ice age some 10,000 years ago — and entered what is increasingly described as a geological epoch or age of our own making? (A 2011 paper, “The Anthropocene: conceptual and historical perspectives,” is the best scientific overview; also read this fine Paul Voosen story on the Anthropocene concept .)

As Ian Sample reported in The Guardian , some geologists frown on the idea:

Phil Gibbard, a geologist at Cambridge who set up the working group in the first place, is one. “ I’m not in favour of this being defined formally as a division of geological time. I think it’s an extraordinarily difficult thing to do,” he said. “We are living in an interglacial period and there’s no question we’re still within that period, and it’s called the holocene.”

But the consensus of those gathered on Thursday was clearly in support of the Anthropocene, although there are still plenty of questions to answer — like whether it’s an age within the Holocene or a new geological epoch in its own right, and when it started. (The consensus on Thursday appeared to be the mid twentieth century, reflecting various indicators of humanity’s surge, from exponential growth in resource extraction to radionuclides from nuclear weapon tests .)

Another question on the table at the meeting was whether the Anthropocene deserves a spike like this one near Pueblo, Colo. , which indicates the beginning of the Turonian Age , 93.5 million years ago.

Big transitions in the planet’s geological history get a “golden spike,” a bronze marker placed on a particular exposed rock layer that serves as a reference for a substantial global shift in conditions. The formal term is a Global Boundary Stratotype Section and Point (GSSP ). Other more murky transitions are demarcated by a date, or Global Standard Stratigraphic Age (GSSA ).

A formal decision won’t come for several years as this working group’s findings work their way up the earth sciences chain. (It will also be vital for the initial team — very white, Western and male — to shift to a composition more representative of the global population.)

On Friday and through the weekend, the host institution for the meeting, Berlin’s House of World Cultures , which has focused on the Anthropocene for two years, will hold a series of arts events and discussions surrounding the science.

Disclosure note | I’m a member of the Anthropocene Working Group because of my 1992 book on global warming , in which I proposed one of various framings of this era:

"Perhaps earth scientists of the future will name this new post-Holocene era for its causative element — for us. 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."

Does the Anthropocene, the Age of Humans, Deserve a Golden Spike? - NYTimes.com

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