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Are we now living in the Anthropocene? GSA Today


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The term Anthropocene, proposed and increasingly employed to denote the current interval of anthropogenic global environ- mental change, may be discussed on stratigraphic grounds. A case can be made for its consideration as a formal epoch in that, since the start of the Industrial Revolution, Earth has endured changes sufficient to leave a global stratigraphic signature dis- tinct from that of the Holocene or of previous Pleistocene inter- glacial phases, encompassing novel biotic, sedimentary, and geochemical change. These changes, although likely only in their initial phases, are sufficiently distinct and robustly estab- lished for suggestions of a Holocene-Anthropocene bound- ary in the recent historical past to be geologically reasonable. The boundary may be defined either via Global Stratigraphic Section and Point ("golden spike") locations or by adopting a numerical date. Formal adoption of this term in the near future will largely depend on its utility, particularly to earth scientists working on late Holocene successions. This datum, from the perspective of the far future, will most probably approximate a distinctive stratigraphic boundary.
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GSA Today: v. 18, no. 2, doi: 10.1130/GSAT01802A.1
Are we now living in the Anthropocene?
Jan Zalasiewicz, Mark Williams, Department of Geology,
University of Leicester, Leicester LE1 7RH, UK; Alan Smith,
Department of Earth Sciences, University of Cambridge,
Cambridge CB2 3EQ, UK; Tiffany L. Barry, Angela L. Coe,
Department of Earth Sciences, The Open University, Walton
Hall, Milton Keynes MK7 6AA, UK; Paul R. Bown, Department
of Earth Sciences, University College London, Gower Street,
London, WC1E 6BT, UK; Patrick Brenchley, Department of
Earth Sciences, University of Liverpool, Liverpool L69 3BX, UK;
David Cantrill, Royal Botanic Gardens, Birdwood Avenue,
South Yarra, Melbourne, Victoria, Australia; Andrew Gale,
School of Earth and Environmental Sciences, University of
Portsmouth, Portsmouth, Hampshire PO1 3QL, UK, and
Department of Palaeontology, Natural History Museum,
London SW7 5BD, UK; Philip Gibbard, Department of
Geography, University of Cambridge, Downing Place,
Cambridge CB2 3EN, UK; F. John Gregory, Petro-Strat Ltd, 33
Royston Road, St. Albans, Herts AL1 5NF, UK, and Department
of Palaeontology, Natural History Museum, London SW7 5BD,
UK; Mark W. Hounslow, Centre for Environmental Magnetism
and Palaeomagnetism, Geography Department, Lancaster
University, Lancaster LA1 4YB, UK; Andrew C. Kerr, Paul
Pearson, School of Earth, Ocean and Planetary Sciences,
Cardiff University, Main Building, Park Place, Cardiff CF10
3YE, UK; Robert Knox, John Powell, Colin Waters, British
Geological Survey, Keyworth, Nottinghamshire NG12 5GG,
UK; John Marshall, National Oceanography Centre, University
of Southampton, University Road, Southampton SO14 3ZH,
UK; Michael Oates, BG Group plc, 100 Thames Valley Park
Drive, Reading RG6 1PT, UK; Peter Rawson, Scarborough
Centre for Environmental and Marine Sciences, University of
Hull, Scarborough Campus, Filey Road, Scarborough YO11
3AZ, UK, and Department of Earth Sciences, University
College London, Gower Street, London WC1E 6BT, UK; and
Philip Stone, British Geological Survey, Murchison House,
Edinburgh EH9 3LA, UK
The term Anthropocene, proposed and increasingly employed
to denote the current interval of anthropogenic global environ-
mental change, may be discussed on stratigraphic grounds. A
case can be made for its consideration as a formal epoch in that,
since the start of the Industrial Revolution, Earth has endured
changes sufficient to leave a global stratigraphic signature dis-
tinct from that of the Holocene or of previous Pleistocene inter-
glacial phases, encompassing novel biotic, sedimentary, and
geochemical change. These changes, although likely only in
their initial phases, are sufficiently distinct and robustly estab-
lished for suggestions of a Holocene–Anthropocene bound-
ary in the recent historical past to be geologically reasonable.
The boundary may be defined either via Global Stratigraphic
Section and Point (“golden spike”) locations or by adopting a
numerical date. Formal adoption of this term in the near future
will largely depend on its utility, particularly to earth scientists
working on late Holocene successions. This datum, from the
perspective of the far future, will most probably approximate a
distinctive stratigraphic boundary.
In 2002, Paul Crutzen, the Nobel Prize–winning chemist, sug-
gested that we had left the Holocene and had entered a new
Epoch—the Anthropocene—because of the global environ-
mental effects of increased human population and economic
development. The term has entered the geological literature
informally (e.g., Steffen et al., 2004; Syvitski et al., 2005; Cross-
land, 2005; Andersson et al., 2005) to denote the contemporary
global environment dominated by human activity. Here, mem-
bers of the Stratigraphy Commission of the Geological Society
of London 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.
The Holocene is the latest of many Quaternary interglacial
phases and the only one to be accorded the status of an epoch;
it is also the only unit in the whole of the Phanerozoic—the
past 542 m.y.—whose base is defined in terms of numbers
of years from the present, taken as 10,000 radiocarbon years
before 1950. The bases of all other periods, epochs, and ages
from the Cambrian onward are defined by—or shortly will be
defined by—“golden spikes” (Gradstein et al., 2004), in which
a suitable section is chosen as a Global Stratotype Section, the
“golden spike” being placed at an agreed point within it, giving
rise to a Global Stratigraphic Section and Point, or GSSP.
To bring the definition of the base of the Holocene into line
with all other Phanerozoic boundaries, there are intentions to cre-
ate a GSSP for the base of the Holocene in an ice core, specifically
in the North Greenland Ice Core Project (NGRIP) ice core, at the
beginning of an interval at which deuterium values (a proxy for
local air temperature) rise, an event rapidly followed by a marked
decrease in dust levels and an increase in ice layer thickness (ICS,
2006). This level lies very near the beginning of the changes that
ushered in interglacial conditions, but is some 1700 yr older than
the current definition for the base of the Holocene. One might
question whether ice is a suitably permanent material, but in this
instance it is important that the GSSP is a tangible horizon within
a stratigraphic sequence, a “time plane” marking an elapsed, dis-
tinctive, and correlatable geological event rather than an arbitrary
or “abstract” numerical age. We note here, though (and discuss
further below), that this logic need not necessarily be followed in
any putative definition of the beginning of the Anthropocene.
The early Holocene was a time of pronounced rises in global
temperature, stabilizing at ca. 11,000 cal. yr B.P., and sea level,
stabilizing at ca. 8000 cal. yr B.P. (Fig. 1). Temperatures and sea
level then reached a marked plateau where they have, until very
recently, remained. This climate plateau, though modulated by
millennial-scale global temperature oscillations of ~1 °C ampli-
tude, represents the longest interval of stability of climate and
sea level in at least the past 400,000 yr. This stability has been a
significant factor in the development of human civilization.
Prior to the Industrial Revolution, the global human population
was some 300 million at A.D. 1000, 500 million at A.D. 1500, and
790 million by A.D. 1750 (United Nations, 1999), and exploitation
of energy was limited mostly to firewood and muscle power. Evi-
dence recorded in Holocene strata indicates increasing levels of
human influence, though human remains and artifacts are mostly
rare. Stratigraphic signals from the mid-part of the epoch in areas
settled by humans are predominantly biotic (pollen of weeds
and cultivars following land clearance for agriculture) with more
ambiguous sedimentary signals (such as sediment pulses from
deforested regions). Atmospheric lead pollution is registered in
polar ice caps and peat bog deposits from Greco-Roman times
onward (Dunlap et al., 1999; Paula and Geraldes, 2003), and
it has been argued that the early to mid-Holocene increase in
atmospheric carbon dioxide from ~260–280 ppm, a factor in the
climatic warmth of this interval, resulted from forest clearance
by humans (Ruddiman, 2003). Human activity then may help
characterize Holocene strata, but it did not create new, global
environmental conditions that could translate into a fundamen-
tally different stratigraphic signal.
From the beginning of the Industrial Revolution to the pres-
ent day, global human population has climbed rapidly from
under a billion to its current 6.5 billion (Fig. 1), and it continues
to rise. The exploitation of coal, oil, and gas in particular has
enabled planet-wide industrialization, construction, and mass
transport, the ensuing changes encompassing a wide variety of
phenomena, summarized as follows.
Changes to Physical Sedimentation
Humans have caused a dramatic increase in erosion and the
denudation of the continents, both directly, through agriculture
and construction, and indirectly, by damming most major riv-
ers, that now exceeds natural sediment production by an order
of magnitude (Hooke, 2000; Wilkinson, 2005; Syvitski et al.,
2005; see Fig. 1). This equates to a distinct lithostratigraphic
signal, particularly when considered alongside the preservable
human artifacts (e.g., the “Made Ground” of British Geological
Survey maps) associated with accelerated industrialization.
Carbon Cycle Perturbation and Temperature
Carbon dioxide levels (379 ppm in 2005) are over a third higher
than in pre-industrial times and at any time in the past 0.9 m.y.
(IPCC, 2007; EPICA community members, 2004). Conservatively,
these levels are predicted to double by the end of the twenty-first
century (IPCC, 2007). Methane concentrations in the atmosphere
have already roughly doubled. These changes have been consid-
erably more rapid than those associated with glacial-interglacial
transitions (Fig. 1; cf. Monnin et al., 2001).
Global temperature has lagged behind this increase in green-
house gas levels, perhaps as a result of industrially derived
sulfate aerosols (the “global dimming” effect; Coakley, 2005).
Figure 1. Comparison of some major stratigraphically significant trends
over the past 15,000 yr. Trends typical of the bulk of immediately pre-
Holocene and Holocene time are compared with those of the past two
centuries. Data compiled from sources including Hooke (1994), Monnin
et al. (2001), Wilkinson (2005), and Behre (2007).
Nevertheless, temperatures in the past century rose overall, the
rate of increase accelerating in the past two decades (Fig. 1).
There is now scientific consensus that anthropogenic carbon
emissions are the cause (King, 2004; IPCC, 2007). Temperature
is predicted to rise by 1.1 °C to 6.4 °C by the end of this century
(IPCC, 2007), leading to global temperatures not encountered
since the Tertiary. The predicted temperatures are similar to the
estimated 5 °C average global temperature rises in the Toarcian
(ca. 180 Ma) and at the Paleocene-Eocene thermal maximum
(PETM, ca. 56 Ma), which were most probably linked to natu-
ral carbon releases into the atmosphere (Thomas et al., 2002;
Kemp et al., 2005). While the likely societal effects are clear,
in our present analysis we focus on the stratigraphic conse-
quences of increased temperature.
Biotic Change
Humans have caused extinctions of animal and plant spe-
cies, possibly as early as the late Pleistocene, with the dis-
appearance of a large proportion of the terrestrial megafauna
(Barnosky et al., 2004). Accelerated extinctions and biotic pop-
ulation declines on land have spread into the shallow seas,
notably on coral reefs (Bellwood et al., 2004) and the oceans
(Baum et al., 2003; Myers and Worm, 2003). The rate of biotic
change may produce a major extinction event (Wilson, 2002)
analogous to those that took place at the K-T boundary and
elsewhere in the stratigraphic column.
The projected temperature rise will certainly cause changes in
habitat beyond environmental tolerance for many taxa (Thomas
et al., 2004). The effects will be more severe than in past glacial-
interglacial transitions because, with the anthropogenic fragmen-
tation of natural ecosystems, “escape” routes are fewer.
The combination of extinctions, global species migrations
(Cox, 2004), and the widespread replacement of natural vege-
tation with agricultural monocultures is producing a distinctive
contemporary biostratigraphic signal. These effects are perma-
nent, as future evolution will take place from surviving (and
frequently anthropogenically relocated) stocks.
Ocean Changes
Pre-industrial mid- to late Holocene sea-level stability has
followed an ~120 m rise from the late Pleistocene level (Fig. 1).
Slight rises in sea level have been noted over the past century,
ascribed to a combination of ice melt and thermal expansion of
the oceans (IPCC, 2007). The rate and extent of near-future sea-
level rise depends on a range of factors that affect snow pro-
duction and ice melt; the IPCC (2007) predicted a 0.19–0.58 m
rise by 2100. This prediction does not factor in recent evidence
of dynamic ice-sheet behavior and accelerating ice loss (Rignot
and Thomas, 2002; Overpeck et al., 2006; Hansen et al., 2007)
possibly analogous to those preceding “Heinrich events” of the
late Pleistocene and early Holocene, when repeated episodes
of ice-sheet collapse (Bond et al., 1992) caused concomitant
rapid sea-level rise (Blanchon and Shaw, 1995). Current pre-
dictions are short-term, while changes to the final equilibrium
state may be as large as a 10–30 m sea-level rise per 1 °C tem-
perature rise (Rahmstorf, 2007).
Relative to pre–Industrial Revolution oceans, surface ocean
waters are now 0.1 pH units more acidic due to anthropo-
genic carbon release (Caldeira and Wickett, 2003), a change
echoed in the stable carbon isotope composition of contem-
porary foraminiferal tests (Al-Rousan et al., 2004). The future
amount of this acidification, scaled to projected future carbon
emissions, its spread through the ocean water column, and its
eventual neutralization (over many millennia) has been mod-
eled (Barker et al., 2003). Projected effects will be physical
(neutralization of the excess acid by dissolution of ocean-floor
carbonate sediment, hence creating a widespread non sequence)
and biological (hindering carbonate-secreting organisms in
building their skeletons), with potentially severe effects in both
benthic (especially coral reef) and planktonic settings (Riebe-
sell et al., 2000; Orr et al., 2005). A similar acidification event
accompanied the PETM at ca. 56 Ma, and, indeed, its effect in
dissolving strata has hindered the precise deciphering of that
event (Zachos et al., 2005).
The sensitivity of climate to greenhouse gases, and the scale
of (historically) modern biotic change, makes it likely that we
have entered a stratigraphic interval without close parallel in
any previous Quaternary interglacial. The nearest parallels
seem to be earlier episodes of high atmospheric pCO2 and
global warming (e.g., Toarcian; the PETM), but the ice volumes
then were small, and melting caused only modest sea-level
rises (~20 m at the PETM, partly through thermal expansion;
Speijer and Marsi, 2002; Speijer and Wagner, 2002). The mid-
Pliocene, at 3 Ma, may be a closer analogue: atmospheric pCO2
levels may have reached 380 ppm, and the polar ice caps were
somewhat smaller than present, with global sea level higher by
10–20 m (Dowsett et al., 1999; Dowsett, 2007).
The present interval might evolve into the “super-interglacial”
envisaged by Broecker (1987), with Earth reverting to climates
and sea levels last seen in warmer phases of the Miocene or
Pliocene (Haywood et al., 2005), most likely achieved via a
geologically abrupt rearrangement of the ocean-atmosphere
system (Broecker, 1997; Schneider, 2004). Such a warm phase
will likely last considerably longer than normal Quaternary
interglacials. It is not clear that an equilibrium comparable to
that of pre-industrial Quaternary time will eventually resume.
Formal subdivision of the Phanerozoic timescale is not sim-
ply a numerical exercise of parceling up time into units of
equal length akin to the centuries and millennia of recent his-
tory. Rather, the geological timescale is based upon recogniz-
ing distinctive events within strata. Time may be divided into
specific, recognizable phases in Earth’s environmental history
(in particular as regards biota, climate, and sea level), akin to
the use of royal dynasties to denote periods of human history
(e.g., the Victorian period of the nineteenth and earliest twenti-
eth centuries). Such concepts of the “naturalness” of boundar-
ies underlie, for example, the current debates on the position-
ing of the boundary of the Quaternary period (Gibbard et al.,
2005) and on subdivision of the Precambrian (Bleeker, 2004).
Geologically, units of equivalent rank do not necessarily
have to be of equivalent time span, particularly as the present
is approached. Thus, the Quaternary, whether its beginning is
placed at 1.8 Ma or 2.6 Ma, is by an order of magnitude the
shortest period, while the Holocene, at a little under 12,000
calendar years (ICS, 2006) is, by at least two orders of magni-
tude, the shortest epoch. This inequality has not been seriously
disputed, partly because of its practical usefulness. The preced-
ing discussion makes clear that we have entered a distinctive
phase of Earth’s evolution that satisfies geologists’ criteria for
its recognition as a distinctive stratigraphic unit, to which the
name Anthropocene has already been informally given.
We consider it most reasonable for this new unit to be consid-
ered at epoch level. It is true that the long-term consequences
of anthropogenic change might be of sufficient magnitude to
precipitate the return of “Tertiary” levels of ice volume, sea
level, and global temperature that may then persist over several
eccentricity (100 k.y.) cycles (e.g., Tyrrell et al., 2007). This,
especially in combination with a major extinction event, would
effectively bring the Quaternary period to an end. However,
given the large uncertainties in the future trajectory of climate
and biodiversity, and the large and currently unpredictable
action of feedbacks in the earth system, we prefer to remain
conservative. Thus, while there is strong evidence to suggest
that we are no longer living in the Holocene (as regards the
processes affecting the production and character of contempo-
rary strata), it is too early to state whether or not the Quater-
nary has come to an end.
For a new epoch to be formally established, either a GSSP
needs to be selected or a date for its inception needs to be
accepted, which is then ratified by the International Commis-
sion on Stratigraphy (ICS). Because it should be possible to
select a stratigraphic unit whose age is known in years, the
Anthropocene can be defined simultaneously by both criteria,
without the uncertainty that bedevils attempts to date older
GSSPs. In theory, a point in a section, or a date, that coincides
with the end of the pre-industrial Holocene could be selected.
However, given that India and China are currently undergo-
ing their own industrial revolution, the selection of a horizon
marking the end of pre-industrial (western) history may be
inappropriate. Potential GSSPs and ages should allow strati-
graphic resolution to annual level, and may be best located in
ice cores or stagnant-lake basin cores.
One may consider using the rise of CO2 levels above back-
ground levels as a marker, roughly at the beginning of the Indus-
trial Revolution in the West (following Crutzen, 2002), or the sta-
ble carbon isotope changes reflecting the influx of anthropogenic
carbon (Al-Rousan et al., 2004). However, although abrupt on
centennial-millennial timescales, these changes are too gradual to
provide useful markers at an annual or decadal level (while the
CO2 record in ice cores, also, is offset from that of the enclosing
ice layers by the time taken to isolate the air bubbles from the
atmosphere during compaction of the snow).
From a practical viewpoint, a globally identifiable level is
provided by the global spread of radioactive isotopes created
by the atomic bomb tests of the 1960s; however, this post-
dates the major inflection in global human activity. Perhaps the
best stratigraphic marker near the beginning of the nineteenth
century has a natural cause: the eruption of Mount Tambora
in April 1815, which produced the “year without a summer”
in the Northern Hemisphere and left a marked aerosol sul-
fate “spike” in ice layers in both Greenland and Antarctica and
a distinct signal in the dendrochronological record (Oppen-
heimer, 2003).
In the case of the Anthropocene, however, it is not clear
that—for current practical purposes—a GSSP is immediately
necessary. At the level of resolution sought, and at this tem-
poral distance, it may be that simply selecting a numerical age
(say the beginning of 1800) may be an equally effective practi-
cal measure. This would allow (for the present and near future)
simple and unambiguous correlation of the stratigraphical and
historical records and give consistent utility and meaning to
this as yet informal (but increasingly used) term.
Sufficient evidence has emerged of stratigraphically signifi-
cant change (both elapsed and imminent) for recognition of
the Anthropocene—currently a vivid yet informal metaphor
of global environmental change—as a new geological epoch
to be considered for formalization by international discussion.
The base of the Anthropocene may be defined by a GSSP in
sediments or ice cores or simply by a numerical date.
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Manuscript received 17 October 2007; accepted 6 November
2007. -
... Ecología Austral 32: I����������� La actividad antrópica global se manifiesta como una influencia geológica reciente. Debido a su efecto acumulativo en la magnitud, la variedad y la durabilidad de los cambios inducidos en la composición atmosférica, en la superficie terrestre y en los ecosistemas marinos o de agua dulce, se propuso denominar a esta época Antropoceno (Crutzen et al. 2000;Crutzen 2002;Steffen et al. 2007;Zalasiewicz et al. 2008;Puig et al. 2016). En este sentido, la presión antrópica sobre la dinámica natural de los ecosistemas de agua dulce, en cualquier escala que ocurra (local, regional o global), no sólo altera sus procesos y patrones ecológicos, sino también conduce a un debilitamiento gradual y drástico de la calidad y cantidad de agua. ...
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En este trabajo se plantean las bases metodológicas para evaluar los cambios antrópicos que afectan las condiciones ecohidrológicas a una escala regional en la Argentina. La diversidad climática, morfológica y geológica del territorio se manifiesta en diferentes ecorregiones y en una diversidad elevada de ambientes lóticos y lénticos ligados a los sistemas hídricos. Los caudales diarios, los niveles freáticos, las superficies anegadas o las alturas hidrométricas tienen distinta influencia según la ecorregión considerada en cada sistema hídrico. La información hidrológica histórica con continuidad y los registros con una extensión suficiente para analizar las alteraciones del régimen hidrológico son relativamente escasos y se restringen a 163 estaciones de medición. Se plantea aplicar un modelo conceptual para analizar las alteraciones hidrológicas, seguido del estudio de las variaciones temporales en las condiciones hidrológicas y morfológicas previas a la actividad antrópica (preimpacto), para luego considerar la nueva situación hidrológica-ecológica (post-impacto), a partir de las que se deberán adoptar las medidas apropiadas para mitigar los daños ecológicos cuando se produzcan. Aunque existen diversas metodologías para realizar dicho análisis, considerando la disponibilidad de datos actuales en la Argentina, se propone emplear el marco metodológico fundamentado en el concepto ELOHA (Ecological Limit of Hydrological Alteration) para analizar las alteraciones hidrológicas. Si bien el método holístico brinda mejores resultados y menor incertidumbre, considerando la heterogeneidad, la escasez y la falta de continuidad de registros hidrológicos a nivel general, la técnica propuesta podría resultar una buena aproximación a escala regional. Se concluye que será necesario adaptar las bases metodológicas y las técnicas de análisis a tal condición para crear una base de datos para planificar estratégicamente los recursos hídricos en la Argentina.
... The term 'Anthropocene' is now firmly embedded in earth science literature, following its introduction by Paul Crutzen to refer to a new geological epoch/period characterized by the increasing human impact on Earth's geological, biological and climatic systems (Crutzen and Stoermer, 2000;Crutzen, 2002Crutzen, , 2009. The concept of the Anthropocene as a new epoch following the Holocene was explored further by the Stratigraphy Commission of the Geological Society of London (Zalasiewicz et al., 2008(Zalasiewicz et al., ) leading, in 2009, to the establishment of the Anthropocene Working Group (AWG) within the Subcommission on Quaternary Stratigraphy (SQS) of the International Commission on Stratigraphy (ICS). The AWG is evaluating the Anthropocene as a potential unit of series/epoch status in the International Chronostratigraphic Chart upon which the Geological Timescale (GTS) is based (Waters et al., 2014). ...
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Over the course of the last decade the concept of the Anthropocene has become widely established within and beyond the geoscientific literature but its boundaries remain undefined. Formal definition of the Anthropocene as a chronostratigraphical series and geochronological epoch following the Holocene, at a fixed horizon and with a precise global start date, has been proposed, but fails to account for the diachronic nature of human impacts on global environmental systems during the late Quaternary. By contrast, defining the Anthropocene as an ongoing geological event more closely reflects the reality of both historical and ongoing human–environment interactions, encapsulating spatial and temporal heterogeneity, as well as diverse social and environmental processes that characterize anthropogenic global changes. Thus, an Anthropocene Event incorporates a substantially wider range of anthropogenic environmental and cultural effects, while at the same time applying more readily in different academic contexts than would be the case with a rigidly defined Anthropocene Series/Epoch.
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El presente volumen recoge las aportaciones que, con motivo de la celebración del XXI Coloquio de Historia de la Educación de la Sociedad Española de Historia de la Educación (SEDHE) en la Universitat de València del 6 al 8 de julio de 2022, se debatieron en el mismo. Los trabajos académicos analizan en perspectiva histórico-educativa las llamadas Pedagogías alternativas y la educación en los márgenes a lo largo de todo el siglo XX, atendiendo a la llamada al estudio de teorías, políticas y prácticas, pensamiento pedagógico y experiencias educativas, que fueron diseñadas, realizadas o que emergieron en los márgenes o como alternativas a los sistemas educativos o a los estándares pedagógicos de los diferentes status quo de cada momento histórico. Las iniciativas educativas al margen o en la frontera de los sistemas educativos, culturales, sociales y políticos establecidos pueden haber supuesto cambios y puntos de inflexión en la historia, rupturas, discontinuidades o bien haber fracasado, quedado en el olvido o simplemente no haber tenido pretensiones universalistas ni de cambio sistémico. Todas estas experiencias pedagógicas son interesantes para el estudio, la reflexión, el debate y el análisis sobre las transformaciones o conservaciones sociales y políticas y su impacto o indiferencia en el curso de la historia de la educación.
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Aim: Field study of the Ekulu River in the coal mining and industrialized part of the Enugu Metropolis was done in order to evaluate the impacts of industrial and technological waste mismanagement on the present and future geology of the Earth. Methodology: The study includes field observation, sampling and description of nature and composition of the sediments from the ancient/abandoned and present/active river channels. Result: The findings of the study shows incorporation of non- decomposable particles such as nylon, plastics, leather, chicken feather, pieces of broken bottles, electrical wire, coal chips, aluminum foil, cloth materials, metallic containers, coal tar and chippings scraped off from failed road etc as part of the present river channel sediments in an active areas such as Onyeama Mine and surroundings and Abakpa Bridge. Conclusion: Occurrence of these debris referred to as “Technofossils” in the sediments and sedimentary rocks that is or will be preserved in these fluvial settings now and in the near future will serve as one of the evidences of human impacts on the Earth System through the use of technological inventions and industrial revolution. These anthropogenic materials in the present river channel sediments are markers which support the argument on a clear shift in geologic time from Holocene to Anthropocene, a proposed human influenced geologic epoch.
The era in which we live is known geologically as the anthropocene . Conceptualizing it as a psychological phenomenon is rare; this article contributes to that effort. The anthropocene is a potent symbol of destruction, active in psyches of both individuals and the collective. Jung’s Answer to Job examined apocalyptic tragedy in one man’s life. A feature of that tragedy was distinct roles: perpetrator and victim. Considering the apocalyptic possibilities of the anthropocene requires less-distinct separation of those roles. In these times, people’s responses to threat illustrate how the anthropocene is psychologically burdensome, for some people more than others. As do other symbols, the anthropocene places both interior demands and external responsibilities on the psyche. Some are presented, to illustrate a Jungian perspective on the psychological problems and healing imperatives of the era in which we live.
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É inegável que a interferência humana vem trazendo consequências catastróficas para o meio ambiente. Tendo em vista este cenário, a Educação Ambiental busca formar indivíduos críticos e ambientalmente responsáveis, que se preocupem com o meio ambiente e ajam visando a preservação do mesmo. O objetivo deste estudo foi utilizar as ferramentas de mídias digitais para favorecer a divulgação científica e verificar sua efetividade para esclarecer a população. Para isso, realizou-se um estudo de caso com alunos de cursos técnicos integrados ao ensino médio, em um município da região noroeste do Paraná, utilizando como instrumento de investigação os aplicativos Google docs e Nuvem de Palavras. Os resultados foram analisados por meio do método indutivo e de Análise de Conteúdo. A utilização de tecnologia digital audiovisual facilitou a construção do conceito de Antropoceno pelos alunos. Assim, entende-se que a utilização de mídias e ferramentas digitais pode mediar o processo de ensino-aprendizagem e induzir a reflexão dos indivíduos participantes.
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Il volume nasce da un lavoro di ricerca empirica sullo smart working, avviato nel 2018 e pubblicato nel 2020 con il titolo "Il tempo dello smart working. La PA tra conciliazione, valorizzazione del lavoro e dell’ambiente". La crisi pandemica, esplosa in quello stesso anno, ha messo il mondo del lavoro di fronte alla necessità di fare massiccio ricorso al lavoro da remoto, accelerando anche il processo di alfabetizzazione sulle tecnologie digitali che stentava a decollare soprattutto nel settore pubblico. Il periodo di emergenza ha determinato, nei fatti, una trasformazione culturale e organizzativa la cui portata va ancora attentamente valutata. In queste pagine si tenta di smontare la vecchia narrazione sulla intoccabilità dei luoghi di lavoro – attorno a cui tradizionalmente ruota l’esistenza di chi lavora e del suo nucleo familiare – e da cui prende forma il territorio nella sua articolazione infrastrutturale e dei servizi che mette a disposizione. L’analisi propone il confronto di quattro diversi contesti della provincia italiana, con l’obiettivo di pervenire a un quadro conoscitivo delle interconnessioni complesse che operano, all’interno di una comunità, fra individui, gruppi, aziende e istituzioni che, nel loro insieme, costituiscono i vincoli e le opportunità per lo sviluppo del territorio stesso. Dall’analisi delle esperienze e dei comportamenti di chi ha sperimentato il nuovo modello di organizzazione del lavoro più agile e flessibile, dal punto di vista temporale e logistico, si perviene alla conclusione che lo Smart working può essere considerato come importante strumento di supporto alle politiche sulla mobilità urbana. Ripensare la mobilità urbana in tale ottica consente di ripensare la nuova relazione tra territorio, comunità e mondo del lavoro, alleggerendo la pressione ambientale e migliorando la qualità dei territori e la vita dei suoi abitanti.
In the 1940s, the American ecologist Aldo Leopold (see Chapter 2) coined the concept of land ethics (Leopold, A.: A sand county almanac: And sketches here and there. Oxford University Press, 1949), which expresses the need to establish a new relationship between human communities and nature on a moral basis, identifying ‘conservation’ as the ethical criterion on which to base this relationship. Conserving ecological systems makes it possible to recover the state of harmony between human beings and the natural environment.
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This article deals with the identification of some general guidelines for teaching aimed at developing futures thinking about themes of the Anthropocene. For that, we estimate such teaching activities at the intersection of socioscientific issues, environmental education, and futures education. We describe two teaching contexts designed on this principle, and centered on pupils’ writing fictional narratives, and analyze the effects on their futures thinking. The results show that it is important to design teaching activities that make it possible to think about the temporalities of processes and phenomena, and to invest in relational responsibilities. In order for the pedagogical activity to take temporalities into account, we propose that the backgrounds of the futures on which the stories take place be built using the scenario method. Writing short stories can also allow for a deeper understanding of relational responsibilities, based more on the framework of capabilities. One perspective is to integrate fictional short stories writing into the repertoire of possible activities to be conducted in an inquiry-based pedagogy about the Anthropocene.
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The behavior of the ocean carbon cycle has been, and will continue to be, modified by the increase in atmospheric CO2 due to fossil fuel combustion and land-use emissions of this gas. The consequences of a high-CO2 world and increasing riverine transport of organic matter and nutrients arising from human activities were investigated by means of two biogeochemical box models. Model numerical simulations ranging from the year 1700 to 2300 show that the global coastal ocean changes from a net source to a net sink of atmospheric CO2 over time; in the 18th and 19th centuries, the direction of the CO2 flux was from coastal surface waters to the atmosphere, whereas at present or in the near future the net CO2 flux is into coastal surface waters. These results agree well with recent syntheses of measurements of air-sea CO2 exchange fluxes from various coastal ocean environments. The model calculations also show that coastal ocean surface water carbonate saturation state would decrease 46 percent by the year 2100 and 73 percent by 2300. Observational evidence from the Pacific and Atlantic Oceans shows that the carbonate saturation state of surface ocean waters has already declined during recent decades. For atolls and other semi-enclosed carbonate systems, the rate of decline depends strongly on the residence time of the water in the system. Based on the experimentally observed positive relationship between saturation state and calcification rate for many calcifying organisms, biogenic production of CaCO3 may decrease by 42 percent by the year 2100 and by 85 to 90 percent by 2300 relative to its value of about 24 × 1012 moles C/yr in the year 2000. If the predicted change in carbonate production were to occur along with rising temperatures, it would make it difficult for coral reef and other carbonate systems, to exist as we know them now into future centuries. Because high-latitude, cold-water carbonates presently occur in waters closer to saturation with respect to carbonate minerals than the more strongly supersaturated waters of the lower latitudes, it might be anticipated that the cool-water carbonate systems might feel the effects of rising atmospheric CO2 (and temperature) before those at lower latitudes. In addition, modeling results show that the carbonate saturation state of coastal sediment pore water will decrease in the future owing to a decreasing pore water pH and increasing CO2 concentrations attributable to greater deposition and remineralization of land-derived and in situ produced organic matter in sediments. The lowered carbonate saturation state drives selective dissolution of metastable carbonate minerals while a metastable equilibrium is maintained between the pore water and the most soluble carbonate phase present in the sediments. In the future, the average composition of carbonate sediments and cements may change as the more soluble Mg-calcites and aragonite are preferentially dissolved and phases of lower solubility, such as calcites with lower magnesium content, increase in percentage abundance in the sediments.
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Traditional reconstructions of sea-surface temperatures (SSTs) produced by the PRISM Group (Pliocene Research Interpretations and Synoptic Mapping) indicate that mid Pliocene surface ocean temperatures were unchanged relative to modern at the tropics and low-latitudes and significantly warmer at higher latitudes, particularly in the North Atlantic. This change in the latitudinal pattern of SSTs has been attributed to enhanced meridional ocean heat transport generated by more vigorous surface ocean gyres and/or thermohaline circulation. This study assesses established SST reconstructions for the mid Pliocene through the application of combined data/modeling techniques. New SST estimates were derived using alkenone paleothermometry at three tropical/subtropical Pacific sites. Published alkenone SST estimates for the Atlantic Ocean were also utilized. The new SST data were combined with predicted SSTs derived from a fully-coupled mid Pliocene ocean-atmosphere general circulation model. Significant differences are noted between absolute PRISM, alkenone and model-predicted SSTs. These differences are generated by errors in the PRISM and alkenone paleothermometry estimates as well as limitations of the climate model itself. However, alkenone and model-based SST estimates are consistent in that both predict a pattern of SST warming during the mid Pliocene in tropical and low-latitude regions, which contrasts with PRISM's estimates of unchanged SST in these regions. The latitudinal pattern of SSTs, produced by alkenone estimates and modeling, is not characteristic of that produced by enhanced meridional ocean heat transport or thermohaline circulation. Instead the pattern is similar to that which might be expected as a result of higher concentrations of atmospheric CO2, which would act to warm the oceans globally.
Fossil fuels will have large impacts on ocean chemistry and climate during the period while they are being burnt (and carbon dioxide emitted) in large amounts. It is frequently assumed that these impacts will fade away soon thereafter. Recent model results, by contrast, suggest that significant impacts will persist for hundreds of thousands of years after emissions cease. We present a new analysis that supports these model findings by elucidating the cause of this ‘fossil fuel hangover’ phenomenon. We explain why the carbonate compensation feedback is atypical, compared to other feedbacks, in the sense that convergence is back towards a new steady-state that is distinct from the starting state. We also calculate in greater detail the predicted implications for the future ocean and atmosphere. The post-fossil fuel long-term equilibrium state could differ from the pre-anthropogenic state by as much as 50% for total dissolved inorganic carbon and alkalinity and 100% for atmospheric pCO2, depending on the total amount of future emissions.
Summary Globally we face serious challenges from the effects of climate change. The causal link between global warming and increased greenhouse gas emissions is well established. Carbon dioxide levels are at a higher level than at any time in the past 750 000 years at least, and it is too late to stop further warming and consequent impacts on UK and global societies. Here I summarize the latest scientific evidence for anthropogenic global warming and outline strategies for adapting to its impacts and mitigating the effects in the longer term.Journal of Applied Ecology (2005) doi: 10.1111/j.1365-2664.2005.01089.x
Dramatic warming and upheaval of the carbon system at the end of the Paleocene Epoch have been linked to massive dissociation of sedimentary methane hydrate. However, testing the Paleocene-Eocene thermal maximum hydrate dissociation hypothesis has been hindered by the inability of available proxy records to resolve the initial sequence of events. The cause of the Paleocene-Eocene thermal maximum carbon isotope excursion remains speculative, primarily due to uncertainties in the timing and duration of the Paleocene-Eocene thermal maximum. We present new high-resolution stable isotope records based on analyses of single planktonic and benthic foraminiferal shells from Ocean Drilling Program Site 690 (Weddell Sea, Southern Ocean), demonstrating that the initial carbon isotope excursion was geologically instantaneous and was preceded by a brief period of gradual surface-water warming. Both of these findings support the thermal dissociation of methane hydrate as the cause of the Paleocene-Eocene thermal maximum carbon isotope excursion. Furthermore, the data reveal that the methane-derived carbon was mixed from the surface ocean downward, suggesting that a significant fraction of the initial dissociated hydrate methane reached the atmosphere prior to oxidation.