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L'Anthropocene Working Group (abbreviato AWG, tradotto dall'inglese come 'gruppo di ricerca sull'Antropocene') è un programma di ricerca dedito allo studio dell'Antropocene come unità geocronologica e cronostratigrafica. Il gruppo è stato stabilito nel 2009 come parte della Sottocommissione sulla Stratigrafia del Quaternario (in inglese 'Subcommission on Quaternary Stratigraphy'), un ente a sua volta membro della Commissione internazionale di Stratigrafia (in inglese 'International Commission on Stratigraphy'). Lo scopo dell'AWG, costituito da 35 membri di varia provenienza disciplinare, incluso Paul Crutzen, vincitore del Premio Nobel per la chimica nel 1995 e 'ideatore' del concetto di Antropocene, è di fornire evidenza scientifica all'Unione Internazionale di Scienze Geologiche (in inglese 'International Union of Geological Sciences') per riconoscere l'Antropocene come un'unità geologica discreta nella scala dei tempi geologici, ponendo fine all'epoca geologica attuale e formalmente riconosciuta, l'Olocene.[1]

Storia[modifica | modifica wikitesto]

Prima dell'istituzione dell'Anthropocene Working Group nel 2009, non esistevano programmi di ricerca dediti allo studio dell'Antropocene come possibile unità geologica formalmente riconosciuta nella scala dei tempi geologici. L'idea di introdurre il termine 'Antropocene' (in inglese 'Anthropocene') per identificare l'epoca geologica attuale, ponendo dunque fine all'Olocene, fu informalmente proposta per la prima volta da Paul Crutzen durante una conferenza dell'IGBP (International Geosphere-Biosphere Program), un programma di ricerca focalizzato sullo studio della Terra come sistema, tenutasi a Cuernavaca, in Messico, nel Febbrario del 2000.[2] Nel Maggio dello stesso anno, Crutzen pubblicò, assieme a Eugene Stoermer, un articolo dal titolo "The 'Anthropocene'" nella Newsletter dell'IGBP.[3]

Nel 2002, Crutzen pubblicò un commentario sulla rivista scientifica Nature intitolato "Geology of Mankind" (tradotto come 'Geologia dell'Umanità'). L'articolo riprende tematiche sviluppate precedentemente circa le caratteristiche dell'Antropocene come epoca distinta dall'Olocene, e sull'inizio di questa nuova epoca geologica.[4] Circa un anno dopo la pubblicazione dell'articolo, un dibattito ebbe inizio tra sostenitori della teoria dell'



[[[..............Later in 2002, Crutzen published a commentary on Nature titled "Geology of Mankind" where he further stressed the idea "to assign the term ‘Anthropocene’ to the present, in manyways human-dominated, geological epoch, supplementing the Holocene," with starting date in the late 18th century (at the onset of the Industrial Revolution). Soon after Paul Crutzen published his influential articles, a debate over the beginning of the Anthropocene took place between supporters of the Early Anthropocene Hypothesis, an thesis originally promoted in 2003 by the palaeoclimatologist William Ruddiman dating the beginning of the Anthropocene as far back as the neolithic revolution,[5] and supporters of more recent starting dates, from the late 18th century to the post-WWII Great Acceleration.[6][7]

The discussion over the beginning of the Anthropocene was crucial for the 'stratigraphic turn'[8] that the Anthropocene debate took in the following years. In February 2008, Jan Zalasiewicz and other members of the Stratigraphy Commission of the Geological Society of London published a paper that considered the possibility to "amplify and extend the discussion of the effects referred to by Crutzen and then apply the same criteria used to set up new epochs to ask whether there really is justification or need for a new term, and if so, where and how its boundary might be placed."[9] The article raised the possibility of studying the Anthropocene as a discrete geological unit—a possibility that later led to the establishment of the AWG.

In 2009, the Subcommission on Quaternary Stratigraphy established an Anthropocene Working Group to "examine the status, hierarchical level and definition of the Anthropocene as a potential new formal division of the Geological Time Scale."[10] Some authors have labelled this moment as 'stratigraphic turn'[11] or 'geological turn'[12], in that the establishment of the AWG acknowledged the Anthropocene as an object of geological interest in the scientific community. The AWG has been actively publishing ever since then.

Ricerca[modifica | modifica wikitesto]

The Anthropocene Working Group is one of four workings groups part of the Subcommission on Quaternary Stratigraphy (the other three being the Pleistocene–Holocene boundary working group, Middle/Late Pleistocene boundary working group, and Early/Middle Pleistocene boundary working group).[13] The AWG members (including Paul Crutzen, who was awarded the Nobel prize for chemistry in 1995 for his researcher on ozone depletion; John McNeill, a pioneering researcher in the field of environmental history; and Naomi Oreskes, author of the influential book Merchants of Doubt) have diverse disciplinary backgrounds, ranging from international law, archaeology, and history to philosophy, natural science, and geography. Since no direct funding supports the research program, communication among members happens mostly through email, whereas meetings are usually founded by hosting institutions.

As for most of the epochs in the Phanerozoic (the current Eon, starting 541 million years ago), determining the beginning of the Anthropocene by locating and agreeing upon its lower boundary is a necessary step in its process of formalization. A lower boundary is defined by locating a GSSP (informally known as 'golden spike') in the stratigraphic section of a stage, the chronostratigraphic taxonomic equivalent of an Epoch. Alternativly, if a 'golden spike' cannot be located, a GSSA can be agreed upon, although this methodology is usually implemented for Precambrian boundaries.[14] There is a specific set of rules that a GSSP must fulfill in order to be recognized as a valid primary geologic marker.[15]

A central object of research for the AWG is establishing when, where, and how to locate the lower boundary of the Anthropocene. This means assigning a starting date to the Anthropocene (and an end to the Holocene), locating primary as well as auxilary markers defining Anthropocene geologic record, and determining the proper methodology to implement in the overall process of formalization (GSSP or GSSA, what proxies to use as markers, etc.). Although debates on the taxonomical level of the Anthropocene in the chronostratigraphic chart / geologic time scale (Stage/Age, Series/Epoch, or System/Period) have occurred, the AWG has been considering the Anthropocene to best fit the requirements to be taxonomically recognized as an Epoch.[16]

In January 2014, the Geological Society of London published A Stratigraphical Basis for the Anthropocene,[17] a collection of scientific essays dedicated to assessing and analyzing the anthropogenic signatures defining the Anthropocene, and its requirements to be recognized as a distinct chronostratigraphic unit from the Holocene. The volume constitutes a landmark publication for the AWG, collecting a preliminary body of scientific evidence for the Anthropocene, and establishing research areas and trajectories retraced in the following years.

In February 2019, the AWG published The Anthropocene as a Geological Time Unit: A Guide to the Scientific Evidence and Current Debate. It represents an extensive summary of evidence collected supporting the case of formalization of the Anthropocene as a geological time unit. The synthesis comprehends evidence ragning from stratigraphy, lithostratigraphy, mineralogy, biostratigraphy, chemostratigraphy, to climatology. The monograph also links the Anthropocene to the question concerning anthropogenic climate change, and the role of human technology and the technosphere in impacting on the function of the Earth system. In the first chapter, the authors also provide a genealogy of the term 'Anthropocene,' and a statement of the role of the AWG as a scientific research program.[18]

In May, 2019, the AWG completed a binding vote determining two major research questions:

  • "Should the Anthropocene be treated as a formal chrono-stratigraphic unit defined by a GSSP?"
  • "Should the primary guide for the base of the Anthropocene be one of the stratigraphic signals around the mid-twentieth century of the Common Era?"

Both questions received a positive response, with 29 votes in favour, 4 votes against, and no abstention (33 votes received out of 34 potential voting members).[19]

Temi Affiliati[modifica | modifica wikitesto]

Riferimenti[modifica | modifica wikitesto]

  1. ^ The Anthropocene as a Geological Time Unit: A Guide to the Scientific Evidence and Current Debate, Cambridge, UK, Cambridge University Press, 2019, ISBN 9781108621359.
  2. ^ Christian Schwägerl, The Anthropocene: The Human Era and How It Shapes Our Planet, Synergetic Press, 2014.
  3. ^ The "Anthropocene" (PDF), in IGBP Global Change newsletter, n. 41, May 2000, pp. 17-18.
  4. ^ Geology of Mankind, in Nature, vol. 415, January 3, 2002, p. 23.
  5. ^ The Anthropogenic Greenhouse Era Began Thousands of Years Ago (PDF), in Climatic Change, vol. 61, n. 3, December 2003, pp. 261-293.
  6. ^ How Long Have We Been in the Anthropocene Era?, in Climatic Change, vol. 61, n. 3, December 2003, pp. 251-257.
  7. ^ The Anthropocene: Are Humans Now Overwhelming the Great Forces of Nature? (PDF), in Ambio, vol. 36, n. 8, December 1, 2007, pp. 614-621.
  8. ^ Jeremy Davies, The Birth of the Anthropocene, Berkeley, California, United States, University of California press, February 2018, p. 248, ISBN 9780520289987.
  9. ^ Are we now living in the Anthropocene? (PDF), in GSA Today, vol. 18, n. 2, February 2008, pp. 4-8, DOI:10.1130/GSAT01802A.1.
  10. ^ Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy (International Commission on Stratigraphy) (PDF), in AWG Newsletter, n. 1, December 2009.
  11. ^ The Human Planet: How We Created the Anthropocene, London, Penguin, June 2018, ISBN 9780241280881.
  12. ^ Christophe Bonneuil, The Geological Turn: Narratives of the Antrhopocene, in "The anthropocene and the global environmental crisis: rethinking modernity in a new epoch" by Clive Hamilton, London, Routledge, 2015, ISBN 9781138821248.
  13. ^ Subcommission on Quaternary Stratigraphy: Working Groups, su quaternary.stratigraphy.org.
  14. ^ Defining the Anthropocene, in Nature, vol. 519, March 12, 2015, pp. 171-180.
  15. ^ Jürgen Remane, Guidelines for the establishment of global chronostratigraphic standards by the International Commission on Stratigraphy (ICS) (PDF), in Episodes, vol. 19, 1996, pp. 77–81.
  16. ^ Stratigraphy of the Anthropocene, in Philos Trans A Math Phys Eng Sci, vol. 369, n. 1938, March 13, 2011, pp. 1036-1055, DOI:10.1098/rsta.2010.0315.
  17. ^ A Stratigraphical Basis for the Anthropocene, London, The Geological Society, January 1, 2014, ISBN 9781862396289.
  18. ^ The Anthropocene as a Geological Time Unit: A Guide to the Scientific Evidence and Current Debate, Cambridge, UK, Cambridge University Press, 2019, ISBN 9781108621359.
  19. ^ Subcommission on Quaternary Stratigraphy: Working Group on the ‘Anthropocene’, su quaternary.stratigraphy.org.
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