We’d love your opinion on this article!! Please head to https://www.surveymonkey.com/r/LTZ5HPP and choose your preferred definition of “The Anthropocene”.
If you choose the option of “other” then please email president@aqua.org.au with your other.Votes close at the end of September.
 
First published in Quaternary Australasia, July 2015. – PDF version
Helen C. Bostock1, David J. Lowe2, Richard Gillespie3, Rebecca Priestley4, Rewi M. Newnham5, Scott D. Mooney6
 

Introduction

As early as the late 19th Century, several scientists had suggested that humans were starting to influence the physical environment of planet Earth (e.g. Marsh, 1864; Stoppani, 1873; Arrhenius, 1896; Chamberlain, 1897). This idea was resurrected and expanded in 2000 by Paul Crutzen, a Nobel Prize-winning chemist, and the late Eugene Stoermer, a professor of biology specialising in diatoms, who suggested that we had left the Holocene and entered the “Anthropocene” (Crutzen and Stoermer, 2000). As summarised by Steffen et al. (2011) and Wolfe et al. (2013), these iconoclastic scientists were referring to the Anthropocene as the interval of demonstrable human alteration of global biogeochemical cycles, beginning subtly in the late 18th Century following James Watt’s invention of the coal-fired steam engine, and accelerating markedly in the mid-20th Century (termed “The Great Acceleration”). Thus Crutzen and Stoermer (2000) argued that the Anthropocene should be an epoch, and for a starting date at the beginning of the Industrial Revolution (Monastersky, 2015).

The term Anthropocene is now regularly used in the geological/environmental literature, appearing in nearly 200 peer-reviewed articles in 2012, and three new journals have been launched over the last few years specifically focussed on this topic, namely The Anthropocene Review, Anthropocene, and Elementa: Science of the Anthropocene. In 2014, the Geological Society, London, published A Stratigraphical Basis for the Anthropocene (Waters et al., 2014), a 321-page volume devoted to the subject. The problem is that the Anthropocene has not yet been formally defined and different disciplines (and even scientists within the same discipline) have different viewpoints as to when the Anthropocene began, if at all (Table 1). In addition, most perspectives on this issue are derived from the Northern Hemisphere, although Brown et al. (2013) and Ellis et al. (2013) and some others have taken a more global viewpoint.

Table 1: Dates or ages proposed in the literature for the start of the Anthropocene, arranged in chronological order.

  Event Age or date Geographical extent Reference
1 Use of fire Early Pleistocene Global but highly localised and diachronous Roebroeks and Villa (2011); Glikson (2013)
2 Megafaunal extinction 50,000-600 yrs BP Global but diachronous Barnosky (2014)
3 Origin of agriculture ~11,000 yrs BP to present SW Asia then global Smith and Zeder (2013)
4 Intensification of agriculture ~8,000 yrs BP to present Eurasian then global Ruddiman (2013) (see also Monastersky, 2015)
5 New-Old World collision AD 1492-1800 Eurasia- Americas Lewis and Maslin (2015)
6 Industrial Revolution AD 1760 to present NW Europe then global Crutzen and Stoermer (2000)
7 Tambora eruption (Indonesia) AD 1815 (April) Global: synchronous sulphate fallout at both poles Smith (2014)
8 Great Acceleration AD 1950 Many local events, global influence Waters et al. (2014); Steffen et al. (2015)
9 Nuclear weapon detonation AD 1945 to present (peak AD 1964) Global Steffen et al. (2007); Zalasiewicz et al. (2011; 2015); Wolfe et al. (2013)

Adapted from Lewis and Maslin (2015)

How to define the Anthropocene and when it should start

In 2016, members of the International Commission of Stratigraphy (ICS), as custodians of the formal Geologic Time Scale, will decide whether the Holocene epoch has given way to the Anthropocene and, if so, where the boundary between the two should be placed. As well as the issue of timing, the Anthropocene Working Group (AWG, chaired by Jan Zalasiewicz) of the Subcommission on Quaternary Stratigraphy, which advises ICS, is to recommend which hierarchical status the Anthropocene should attain if adopted. If it is to be a geological “epoch” (i.e. at the same hierarchical level as the Pleistocene and Holocene epochs) then it would lie within the Quaternary Period and follow the (terminated) Holocene Epoch. Alternatively, it could be considered at a lower hierarchical level such as “age”, implying it is a subdivision of the ongoing Holocene Epoch (Monastersky, 2015; see also http://quaternary.stratigraphy.org/workinggroups/anthropocene/).

At the same time the ICS will decide whether to formally adopt a proposal to subdivide the Holocene into three sub-epochs (Walker et al., 2012; Gibbard, 2015). This parallel effort to subdivide the Holocene is relevant to the Anthropocene question because it clearly characterises the Holocene as being based on natural climatic/environmental events, thus leaving open the possibility of a subsequent epoch defined entirely by the global signature of significant human impact on the environment.

The Holocene was formally ratified by the ICS in 2006. It is defined as the most recent epoch of the Quaternary Period, being broadly the time since the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase (11,700 calendar years before the year AD 2000) through to the present day (Walker et al., 2009). The official boundary of the Holocene is defined in the Greenland NGRIP ice core at 1492.45 m depth (marked by an abrupt shift in deuterium excess values), and selected auxiliary lacustrine and marine records, including sediments in Lake Maratoto in northern New Zealand representing the Australasian parastratotype. Holocene stratigraphic records, as well as providing evidence of climate and sea-level change, geomorphological and hydrological processes, vegetational changes, and faunal migrations, also contain archaeological data that attest to the development of society, and the evolving relationships between people and the environment (e.g. Walker et al., 2012; Roberts, 2014). A key problem in attempting to define the Anthropocene is to distinguish between the detection of human impacts and their distribution in time and space, and the point at which the magnitude of human impacts on the Earth system (key biogeochemical cycles) exceeds the influence of the natural systems and which can be recognised in the context of geological time (Steffen et al., 2011; Wolfe et al., 2013). In a nutshell, the Holocene might be seen as totally adequate to cover the former, and the Anthropocene should perhaps be used to cover the latter.

Australasian perspective

In this article we present an Australasian perspective, and invite your feedback and comments, which will be compiled and sent to AWG to help advise the ICS. We do not suggest that Australasian evidence should necessarily be at the forefront of defining the onset or formal stratigraphic status of the Anthropocene, but that the evidence from our region should be compatible with, and should inform, any globally applicable definitions. Because Australia (and Papua New Guinea) and New Zealand (and other Pacific islands of Polynesia) have very different Quaternary histories, they are treated separately in the brief overviews below.

Australia and Papua New Guinea

Based on the dating of occupation and burial sites, humans arrived in Australia and Papua New Guinea around 45,000−50,000 years ago (e.g. Roberts and Jones, 2000; Turney et al., 2001a; Bowler et al., 2003; Allen and O’Connell 2014). Around this time there is also considerable evidence for significant changes in fluvial hydrology and lake levels (Magee et al., 2004; Cohen et al., 2015), evidence for charcoal and biological turnover (Turney et al., 2001b; Mooney et al., 2011), and for the extinction of the megafauna (Roberts et al., 2001; Gillespie, 2008). There is still considerable debate in Australia, partly due to the sparse distribution and often poor quality dating of megafaunal sites, whether human hunting and associated practices, including use of fire, or climate change, or some combination of both, caused the demise of the megafauna (e.g. Miller et al., 2005; Gillespie et al., 2006; Brook et al., 2007, 2013; Prideaux et al., 2010; Rule et al., 2012; Murphy et al., 2012; Price, 2012; Wroe et al., 2013; Cohen et al., 2015). During the early to mid-Holocene period there is evidence for plant domestication in the highlands of Papua New Guinea (Denham et al., 2003; Haberle, 2007), but Aboriginals on mainland Australia primarily remained hunter-gatherers.

The first Europeans landed on Australia in the 17th Century, but large-scale European colonisation did not occur until 1788 with the development of the penal colonies around Sydney and the satellite convict settlements on Norfolk Island (from 1789) and Hobart (1803) (e.g. King, 2003). For the next ~100 years there is considerable evidence from historical and palaeoenvironmental archives that the European settlers had a considerable impact on the landscape, with massive deforestation of the east coast forests especially, leading to changes in the vegetation, increased charcoal in the archives, and large increases in sedimentation in lakes, estuaries, and near-shore environments (Haberle et al., 2006). A significant acceleration of the impact of these and other land-use activities occurred in the 1950s (e.g. Douglas et al., 2010; Gehrels et al., 2012; Macreadie et al., 2012).

Pacific islands and New Zealand

In comparison with the early arrival of humans in Australia, many of the Pacific islands were only discovered and populated by seafaring Polynesians in the Late Holocene, with colonisation of West Polynesia from around 200 BC, central East Polynesia from around AD 900-1100, and Hawaii, Easter Island (Rapanui), and South Polynesia, from around AD 1200-1300 (Anderson, 2015a). The earliest arrival in New Zealand (part of South Polynesia) was not until the 13th Century, possibly around AD 1280 (Lowe and Pittari, 2014). Why New Zealand was settled so late in prehistory is debated, but, as well as being a remote archipelago, its discovery has been linked to the requirement of sophisticated sea craft and navigation and was possibly associated with a peak in El Nino frequencies (e.g. Anderson et al., 2006; Anderson, 2015a, 2015b), or just general changes in the wind systems during this period (Goodwin et al., 2014). The early Polynesians (who culturally became Maori in New Zealand) brought with them domesticated plants and animals (dogs and rats), although some of the tropical plants were not suitable for the New Zealand climate. Evidence from peat, lake, and marine-derived pollen records, lacustrine sedimentation records, and bones of the commensal Pacific rat Rattus exulans, rat-nibbled seed cases and snail-shells, fire records, ancient DNA, and archaeological studies show that Polynesians had a substantial impact on the landscape from around 700 years ago (e.g. Higham and Hogg, 1997; Wilmshurst, 1997; Ogden et al., 1998; Schmidt and Higham, 1998; Higham et al., 1999; McGlone and Wilmshurst, 1999; Brook, 2000; Anderson, 2002, 2005, 2013; Wilmshurst et al., 2008, 2011, 2014; Lowe, 2011; Perry et al., 2012; Jacomb et al., 2014; Anderson, 2015c). There is also considerable evidence that hunting of the local wildlife in New Zealand lead to the extinction of a species of sea lion and many birds (~ 40 species) (Collins et al., 2014), including several megafauna: all nine species of moa (extinct from AD 1440 ± 20; Perry et al., 2014) and Haast’s Eagle (extinct around AD 1400; Tennyson and Martinson, 2006).

Abel Tasman was the first known European to reach New Zealand in AD 1642 with evidence of possible contact by further Dutch explorers after AD 1705 ± 5 (Palmer et al., 2013). Following the arrival of Cook in 1769, there is ample evidence for explorers, missionaries, whalers, sailors and traders, with small whaling and sealing stations around the country from the early 19th Century (e.g. King, 2003). The Treaty of Waitangi was signed in 1840 and large pakeha (primarily British) settlements continued to develop during the 19th Century. Further dramatic changes in the vegetation occurred during this European era, as observed from historical as well as geological and palaeoenvironmental archives. Pollen records in particular indicate resurgence in forest clearances by early pakeha settlers and accompanying introduction of a wide range of exotic plants. The large-scale development of grasslands occurred in the late 19th and early 20th centuries with the so-called “grasslands revolution”, which lead to forest clearance on lowlands through to steeplands, and the widespread and efficacious drainage of wetlands (e.g. King, 2003; Brooking and Pawson, 2011; Cushman, 2013; Brooking and Wood, 2013; Park, 2013). Accelerating soil erosion and measurable environmental geochemical influences are recorded in landscapes and in lake and marine sediments from the 1920s onwards (e.g. Rawlence, 1984; Hume et al., 1989; Page et al., 2004; Augustinus et al., 2006; Gomez et al., 2007; Gehrels et al., 2012; Basher, 2013), with a markedly increased intensification of land use from the 1950s, including the advent of aerial topdressing (from 1948-49), leading eventually to widespread changes (degradation) in water quality (e.g. Pawson and Brooking, 2013).

The Great Acceleration

It is clear that the 1950s was an important decade for both New Zealand and Australia, and it is also an important time globally, with a major expansion of human population after World War II, intensification of land use, and the development of many new technologies and materials (plastic, artificial fertilizers, advent of new breeds of crops such as rice, etc.). This period, as noted earlier, has been called the “Great Acceleration” (e.g. Wolfe et al., 2013; Monastersky, 2015; Steffen et al., 2015). These changes have had a major impact on our atmosphere and climate with atmospheric CO2 and methane rapidly increasing after the 1950s. It is now estimated that nearly half of the nitrogen in our bodies was produced in a factory using the Haber-Bosch process. In addition, ever-enduring plastic can now be found in all parts of the Earth – the current estimates suggest the ratio of plastic to marine life in the world’s major marine gyres is 6 to 1 by weight (Vince, 2014; Kidwell, 2015; Young, 2015). Steffen et al. (2015) emphasise that only beyond the mid-20th Century acceleration is there unequivocal evidence for fundamental shifts in the state and functioning of the Earth system that exceed the range of variability of the Holocene, and which are driven by human activities. Thus these authors consider that the beginning of the Great Acceleration is “by far the most convincing for a start date for the Anthropocene”.

The atom bomb effect

 The mid-20th Century was also the start of the nuclear age. The first nuclear bomb was detonated by the United States of America (USA) on 16 July 1945. In the subsequent nuclear arms race, first the USA and Soviet Union, and then the United Kingdom, France, and China, began developing and testing nuclear weapons of ever-increasing size. The first thermonuclear bomb (or hydrogen bomb) was detonated by the USA in 1952: this new type of bomb, which the Soviet Union first tested in 1953, produced much larger yields of fission products and blasted radioactive isotopes high into the stratosphere where they spread around the world and were deposited as nuclear (radioactive) fallout.

It was a New Zealand scientist, Athol Rafter, who first observed that nuclear weapon detonations – particularly the hydrogen bomb tests – were significantly increasing levels of radiocarbon in the atmosphere. In a 1957 paper he coined the phrase “the atom bomb effect” (Rafter and Fergusson, 1957) and outlined how nuclear weapons tests had doubled atmospheric radiocarbon in the Northern Hemisphere and increased Southern Hemisphere levels by 60%. These increases produced a sudden spike of “bomb carbon” in the 1960s (Figure 1).

Figure 1_bostock et al anthropocene

Figure 1: Atmospheric radiocarbon abundance, showing the fossil fuel effect and nuclear bomb effect (Gillespie, 1984).

 

During 1961-62, many high-yield weapons were tested by the USA and Soviet Union, after which both countries signed the 1963 Limited Test Ban Treaty (tests by France, and then China, continued). In both northern and southern hemispheres, peak strontium-90 (90Sr) and caesium-137 (137Cs) levels were reached in 1964. The two-year delay between peak testing and peak deposition was due to the long residence time of fallout in the stratosphere. In the Southern Hemisphere, peak 90Sr and 137Cs deposition averaged 40% of Northern Hemisphere levels, with higher levels of deposition in areas with higher rainfall (Matthews, 1993).

Golden spike (Global Stratotype Section and Point: GSSP) or global age (Global Standard Stratigraphic Age: GSSA), or both, for the Anthropocene?

For the Anthropocene to become a formal geological unit it needs to be recorded in the geological, sediment, or ice records (preferably all of these archives) as a stratigraphically significant single global event (or at least covering a significant proportion of the globe), and preferably not time-transgressive (i.e. not diachronous). If we accept that the Anthropocene onset must be (largely) globally discernible, the Australasian evidence outlined above precludes definitions 1-5 (Table 1). If we take definition 6 then the rise in CO2 in the ice cores is clear, but it is difficult to define precisely. The initial change in concentrations is gradual, reflecting the sluggish and variable spread in the use of coal, starting in northwest Europe and slowly spreading to North America and then globally. So there is no abrupt change in CO2 or other products associated with the burning of fossil fuels (Lewis and Maslin, 2015), but the marked rise in greenhouse gases nevertheless is evident from the early 1800s (Figure 2). One other suggestion for a golden spike (GSSP) for the early 19th Century (definition 7), relating chronostratigraphically to this greenhouse rise, has been fallout from the Tambora volcanic eruption (Indonesia), which occurred in April 1815, and resulted in a global cooling and “the year without a summer” in the Northern Hemisphere (e.g. Fischer et al., 2007; Smith, 2014). More importantly for generating a global marker, the eruption produced an instantaneous, synchronous, and recognisable aerosol-derived sulphate spike in the ice cores of both Greenland and Antarctica and in glacier ice in North and South America, and a distinct signal in dendrochronological records (Briffa et al., 1998; Oppenheimer, 2003; Smith, 2014). Probable fallout from Tambora in New Zealand was identified by Gehrels et al. (2008) from measurements of lead (Pb) concentrations and isotope values in salt-marsh sediments in southeast South Island. It is likely, on the basis of recent discoveries of cryptotephra deposits (sparse glass-shard concentrations not visible as layers: Lowe, 2011; Davies, 2015) at distances >7000 km from the eruption source (e.g. Lane et al., 2013; Jensen et al., 2014), that glass shards from the Tambora eruption are identifiable as cryptotephras in terrestrial and marine sediments over wide areas of the Earth’s surface, hence potentially providing a definitive isochron or marker ‘bed’ on a hemispheric scale. Thus it could be argued that the Tambora eruption deserves serious consideration as the golden spike because it is a demonstrably globally synchronous signal that ties in with associated evidence of increasing human impact, namely the atmospheric greenhouse gas rise from the early 1800s (Figure 2) (Smith, 2014). Another idea is that this eruption event could simply be seen as a global marker for the start of the ~150 year transition from the Holocene to Anthropocene.

Figure 2_bostock et al anthropocene

Figure 2: Changes in greenhouse gases recorded in ice cores in the last 1000 years with the date of the Tambora eruption (1815) indicated (vertical line). Coloured symbols represent data from Antarctic ice cores: red boxes = Law Dome, green circles = Siple, purple triangles = EPICA DML, blue boxes = South Pole; black boxes are data from GISP2, Greenland. Atmospheric CO2 measurements from Mauna Loa are also plotted (solid blue line) for the last ~50 years. Figure from Smith (2014), after Wolff (2011). Reproduced with acknowledgement and thanks to The Geological Society, London, and to Victoria C. Smith.

 

We would argue, however, that the definition(s) that relate best overall to the evidence in the Australasian region are definitions 8 and 9, respectively the “Great Acceleration” combined with the “Nuclear Age” at around AD 1950 (i.e. between AD 1945 and 1965). It is clear that globally there have been many changes in land use and technology and other developments from the mid-20th Century that have led to fundamental shifts in the functioning of the Earth system to a point where many biophysical indicators now exceed limits of Holocene variability. There is now an unprecedented “emergent, planet-scale coupling, via globalisation, between the socio-economic system and the biophysical Earth System”, according to Steffen et al. (2015). The global fallout of bomb-test radioisotopes has the potential to create a truly global marker horizon for the Anthropocene (Zalasiewicz et al., 2011; 2015). The nuclear weapon detonations introduced a range of radioactive isotopes that can be traced in soil, sediment, ice, tree-ring, and coral archives. Caesium-137 and strontium-90 were first detected in soils in 1952, while there is evidence that bomb radiocarbon in geological archives peaked in 1965 in the Southern Hemisphere, slightly offset by a couple of years from the Northern Hemisphere peak in 1963 and that of the tropics in 1964 (Hua et al., 2013; Zalasiewicz et al., 2015). Unfortunately, not all of these bomb isotopes will be useful for the tracing this event in the geological future because 90Sr and 137Cs have very short half-lives (28 years and 30 years, respectively), while radiocarbon is slightly longer with a half-life of 5,730 years. However, several other isotopes, such as plutonium-239 and iodine-129, have longer half-lives of 24,110 years and 15.7 million years, respectively, and hence the latter should therefore be evident in the geological record effectively indefinitely (Hancock et al., 2014).

Others have argued that the date of around AD 1950 postdates the upward inflection of atmospheric CO2 from fossil fuel combustion in ice cores by more than a century (Fig. 2). However, it is clear from the records that there is also an acceleration in the increase of atmospheric CO2 at this time (Steffen et al., 2015), with evidence that this is the first interval when anthropogenic greenhouse gas forcings dominated over natural climate forcings (Hansen et al., 2008). Thus this ~AD 1950 date fits with the postulated definition of the advent of the Anthropocene as being the point at which the magnitude of human impacts on Earth system (key biogeochemical cycles) exceeds the influence of the natural systems (Wolfe et al., 2013). Taking a rather different, namely microbiological, viewpoint, Gillings and Paulsen (2014) suggested that the ‘Great Acceleration’ be assigned a formal starting date of 1953 (when the structure of DNA was first published) on the grounds that human manipulation of the biological information flows from DNA, to RNA, to protein, and thence to phenotype (a process known as the ‘Central Dogma’ of cell biology), is a major development in the course of evolutionary history. Because such manipulation “has the potential to expand the power of gene technology to whole-Earth scales”, Gillings and Paulsen (2014) concluded that “DNA technology will be a powerful force in our future, and for dealing with the Anthropocene.”

Finally, some have proposed that a GSSA alone may be more appropriate at this time to define the start of the Anthropocene because the community is still fleshing out the full range of physical, chemical, and biological phenomena associated with the postulated Holocene-Anthropocene transition (Zalasiewicz et al., 2011; 2015; Wolfe et al., 2013), and hence a GSSP can wait. However, other scientists completely disagree with all these proposals and believe that we are still in the Holocene and that the “anthropocene” should remain an informal unit (e.g. Autin and Holbrook, 2012; Gale and Hoare, 2012; Smith and Zeder, 2013; Gibbard and Walker, 2014; Ruddiman et al., 2015). In this case, the name would continue to be used in the same way as such archaeological terms as Neolithic and Bronze Age (Monastersky, 2015). Another view is that we are in the transition towards the Anthropocene and need a much longer perspective to assess “the character of the fully developed Anthropocene” and it should be left to future generations to decide (with hindsight) when the Anthropocene began (Wolff, 2014). For example, Ruddiman et al. (2105) suggested that future changes – such as species extinctions and ocean acidification (e.g. Drake et al., 2014) – are projected to be much larger than those already seen but are difficult to predict.

Issues to address include:

  • Should the Anthropocene be formalised as part of the Geological Time Scale?
  • If adopted, when should it start?
  • If adopted, what status should a formally defined Anthropocene have in the hierarchy of the Geological Time Scale: epoch, age, or something else?

Acknowledgement

Mike Walker (UK) is thanked for inspiring HCB to lead the writing of this article after a talk and discussion at the INTIMATE meeting, Zaragoza, Spain 2014.

Author affiliations

1 – National Institute of Water and Atmospheric Research, Private Bag 14901, Wellington 6021, New Zealand
2 – Earth Sciences, School of Science, Faculty of Science and Engineering, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
3 – Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Northfields Avenue, Wollongong NSW 2522, Australia, and Department of Archaeology and Natural History, School of Culture, History and Language, Australian National University, Acton 2601, Australia
4 – Science in Society group, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand
5 – School of Geography, Earth and Environmental Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand
6 – School of Biological and Earth and Environmental Sciences, UNSW, Kensington, Sydney, NSW 2052, Australia 

References

Allen, J, O’Connell, JF. 2014. Both half right: updating the evidence for dating first human arrivals in Sahul. Australian Archaeology 79: 86-108.

Anderson, A.J. 2002. Faunal collapse, landscape change and settlement history in Remote Oceania. World Archaeology 33: 375-390.

Anderson, A.J. 2005. Subpolar settlement in South Polynesia. Antiquity 79: 791-800.

Anderson, A.J. 2013. A fragile plenty: pre-European Maori and the New Zealand environment. In Pawson, E., Brooking, T. (eds), Making a New Land – Environmental Histories of New Zealand, new edition. Otago University Press, Dunedin, pp. 35-51.

Anderson, A. 2015. Ancient origins 3000 BC-AD 1300 [Chapter 1]. In: Anderson, A., Harris, A., Williams, B. (eds) Tangata Whenua – An Illustrated History. Bridget Williams Books, Auckland, pp. 16-41.

Anderson, A. 2015b. Speaking of migration AD 1150-1450 [Chapter 2]. In: Anderson, A., Harris, A., Williams, B. (eds) “Tangata Whenua – An Illustrated History”. Bridget Williams Books, Auckland, pp. 42-69.

Anderson, A. 2015c. Pieces of the past AD 1200-1800 [Chapter 3]. In: Anderson, A., Harris, A., Williams, B. (eds) “Tangata Whenua – An Illustrated History”. Bridget Williams Books, Auckland, pp. 70-101.

Anderson, A., Chappell, J., Gagan, M., Grove, R. 2006. Prehistoric migration in the Pacific islands: an hypothesis of ENSO forcing. The Holocene 16: 1-6.

Arrhenius, S. 1896. On the influence of carbonic acid in the air upon the temperature of the ground. London, Edinburgh Dublin Philosophical Magazine, Journal of Science 41: 237-275.

Augustinus, P., Reid, M., Andersson, S., Deng, Y., Horrocks, M. 2006. Biological and geochemical record of anthropogenic impacts in recent sediments from Lake Pupuke, Auckland City, New Zealand. Journal of Paleolimnology 35: 789-805.

Autin, W.J., Holbrook, J.M. 2012. Is the Anthropocene and issue of stratigraphy or pop culture? Geological Society of America Today 22: 60-61.

Barnosky, A.D. 2014. Palaeontological evidence for defining the Anthropocene. Geological Society, London, Special Publication 395: 149-165.

Basher, L.R. 2013. Erosion processes and their control in New Zealand. In: Dymond, J.R. (ed), Ecosystem Services in New Zealand − Conditions and Trends. Manaaki Whenua Press, Lincoln, pp. 363-374.

Bowler, J.M., Johnston, H., Olley, J.M., Prescott, J.R., Roberts, R.G., Shawcross, W., Spooner, N.A. 2003. New ages for human occupation and climatic change at Lake Mungo, Australia. Nature 421: 837-840.

Briffa, K. R., Jones, P. D., Schweingruber, F. H., Osborn, T. J. 1998. Influence of volcanic eruptions on Northern Hemisphere summer temperature over the past 600 years. Nature 393: 450-455.

Brook, F.J. 2000. Prehistoric predation of the landsnail Placostylus ambagiosus Suter (Stylommatophora: Bulimulidae), and evidence for the timing of establishment of rats in northernmost New Zealand. Journal of the Royal Society of New Zealand 30: 227-241.

Brook, B.W., Bowman, D.M.J.S., Burney, D.A., Flannery, T.F., Gagan, M.K., Gillespie, R., Johnson, C.N., Kershaw, P., Magee, J.W., Martin, P.S., Miller, G.H., Peiser, B., Roberts, R.G. 2007. Would the Australian megafauna have become extinct if humans had never colonised the continent? Quaternary Science Reviews 26: 560-564.

Brook, B.W., Bradshaw, C.J.A., Cooper, A., Johnson, C.N., Worthy, T.H., Bird, M., Gillespie, R., Roberts, R.G. 2013. Lack of chronological support for stepwise prehuman extinctions of Australian megafauna. Proceedings of the National Academy of Sciences of the USA 110: E3368.

Brooking, T., Pawson, E. 2011. Seeds of Empire – the Environmental Transformation of New Zealand. I.B. Tauris, London, 296 pp.

Brooking, T., Wood, V. 2013. The grasslands revolution revisited. In: Pawson, E., Brooking, T. (eds), Making a New Land – Environmental Histories of New Zealand, new edition. Otago University Press, Dunedin, pp. 193-208.

Brown, A.G., Tooth, S., Chiverrell, R.C., Rose, J., Thomas, D.S.G., Wainwright, J., Bullard, J.E., Thorndycraft, V.R., Aaltos, R., Down, P. 2013. The Anthropocene: is there a geomorphological case? Earth Surface Processes and Landforms 38: 431-434.

Chamberlain, T.C. 1897. A group of hypotheses bearing on climatic changes. Journal of Geology 5: 653-683.

Cohen, T.J., Jansen, J.D., Gliganic, L.A., Larson, J.R., Nanson, G.C., May, J-H., Jones, B.G., Price, D.M. 2015. Hydrological transformation coincided with megafaunal extinction in central Australia. Geology: doi:10.1130/G36346.1

Collins, C.J., Rawlence, N.J., Prost, S., Anderson, C.N.K., Knapp, M., Scofield, R.P., Robertson, B.C., Smith, I., Matisoo-Smith, E.A., Chilvers, B.L., Waters, J.M. 2014. Extinction and recolonization of coastal megafauna following human arrival in New Zealand. Proceedings of the Royal Society B: Biological Sciences, 281: 20140097. http://dx.doi.org/10.1098/rspb.2014.0097.

Crutzen, P.J., Stoermer, E.F. 2000. The “Anthropocene”. Global Change Newsletter 41: 17-18.

Cushman, G.T. 2013. Guano and the Opening of the Pacific World – a Global Ecological History. Cambridge University Press, New York, 392pp.

Davies, S.M. 2015. Cryptotephras: the revolution in correlation and precision dating. Journal of Quaternary Science 30: 114-130.

Denham, TP, Haberle, SG, Lentfer, C, Fullagar, R, Field, J, Therin, M, Porch, N, Winsborough, B. 2003. Origins of Agriculture at Kuk Swamp in the Highlands of New Guinea. Science 301: 189-193.

Douglas, G.B., Kuhnen, M., Radke, L.C., Hancock, G. Brooke, B., Palmer, M.J., Pietsch, T., Ford, P.W. Trefry, M.G., Packett, R. 2010. Delineation of sediment sources to a coastal wetland in the Great Barrier Reef catchment: influence of climate variability and land clearing since European arrival. Environmental Chemistry 7: 190-206.

Drake, J.L., Mass, T., Falkowski, P.G. 2014. The evolution and future of carbonate precipitation in marine invertebrates: witnessing extinction or documenting resilience in the Anthropocene? Elementa, doi: 10.12952/journal.elementa.000026.

Ellis, E.C., Fuller, D.Q., Kaplan, J.O., Lutters, W.G. 2013. Dating the Anthropocene: towards an empirical global history of human transformation of the terrestrial biosphere. Elementa, doi: 10.12952/journal.elementa.000018.

Fischer, E.M., Luterbacher, J., Zorita, E., Tett, S.F.B., Casty, C., Wanner, H. 2007. European climate response to tropical volcanic eruptions over the last half millennium. Geophysical Research Letters 34: L05707, doi: 10.1029/2006GL027992.

Gale, S.J., Hoare P.G. 2012. The stratigraphic status of the Anthropocene. The Holocene 22: 1491-1494.

Gehrels, W.R., Hayward, B.W., Newnham, R.M., Southall, K.E. 2008. A 20th century acceleration of sea-level rise in New Zealand. Geophysical Research Letters 35: L02717, 1-5, doi: 10.1029/2007GL032632.

Gehrels, W.R., Callard, S.L., Moss, P.T., Marshall, W.A., Blaauw, M., Hunter, J., Milton, J.A., Garnett, M.H. 2012. Nineteenth and twentieth century sea-level changes in Tasmania and New Zealand. Earth and Planetary Science Letters 315-316: 94-102.

Gibbard, P.L. 2015. The Quaternary System/Period and its major subdivisions. Russian Geology and Geophysics 56: 686-688.

Gibbard, P.L., Walker, M.J.C. 2014. The term ‘Anthropocene’ in the context of formal geological classification. Geological Society, London, Special Publication 395: 29-37.

Gillespie, R. 1984. Radiocarbon Users Handbook. Oxbow Books, Oxford, 36 pp..

Gillespie, R., Brook, B.W., Baynes, A., 2006. Short overlap of people and megafauna in Pleistocene Australia. Alcheringa, Special Issue 1: 163-185.

Gillespie, R., 2008. Updating Martin’s global extinction model. Quaternary Science Reviews 27: 2522-2529.

Gillings, M.R., Paulsen, I.T. 2014. Microbiology of the Anthropocene. Anthropocene 5: 1-8.

Glikson, A. 2013. Fire and human evolution: the deep-time blueprints of the Anthropocene. Anthropocene 3: 89-92.

Goodwin, I.D., Browning, S., Anderson, A. 2014. Climate windows for Polynesian colonisation of Easter Island and New Zealand during the Medieval Climate Anomaly. Proceedings of the National Academy of Science of the USA 111: 14716–14721, doi: 10.1073/pnas.1408918111.

Gomez, B., Carter, L., Trustrum, N.A. 2007. A 2400 yr record of natural events and anthropogenic impacts in intercorrelated terrestrial and marine sediment cores: Waipaoa sedimentary system, New Zealand. Geological Society of America Bulletin 119: 1415-1432.

Haberle, S. G. 2007. Prehistoric human impact on rainforest biodiversity in highland New Guinea. Philosophical Transactions of the Royal Society of London B 362: 219-228.

Haberle, S.G., Tibby, J., Dimitriadis, S., Heijnis, H. 2006. The impact of European occupation on terrestrial and aquatic ecosystem dynamics in an Australian tropical rain forest. Journal of Ecology 94: 987-1002.

Hancock, G.F., Tims, S.G., Fifield, L.K., Webster, I.T., 2014. The release and persistence of radioactive anthropogenic nuclides. Geological Society, London, Special Publication 395, 265-281.

Hansen, J., Sato, M., Kharecha, P., Beerling, D., Berner, R., Masson-Delmotte, V., Pagani, M., Raymo, M., Royer, D.L., Zachos, J.C. 2008. Target atmospheric CO2: where should humanity aim? The Open Atmospheric Science Journal 2: 217-231.

Higham, T.F.G., Hogg, A.G. 1997. Evidence for late Polynesian colonisation of New Zealand: University of Waikato radiocarbon measurements. Radiocarbon 39: 149-192.

Higham, T.F.G., Anderson, A.J., Jacomb, C. 1999. Dating the first New Zealanders: the chronology of Wairau Bar. Antiquity 73: 420-427.

Hua, Q., Barbetti, M., Rakowski, A.Z. 2013. Atmospheric radiocarbon for the period 1950-2010. Radiocarbon 55: 2059-2072.

Hume, T.M., Fox, M.E., Wilcock, R.J. 1989. Use of organochlorine contaminants to measure sedimentation rates in estuaries: a case study from the Manukau Harbour. Journal of the Royal Society of New Zealand 19: 305-317.

Jacomb, A., Holdaway, R.N., Allentoft, M.E., Bunce, M., Oskam, C.L., Walter, R., Brooks, E. 2014. High-precision dating and ancient DNA profiling of moa (Aves: Dinornithiformes) eggshell documents a complex feature at Wairau Bar and refines the chronology of New Zealand settlement by Polynesians. Journal of Archaeological Science 50: 24-30.

Jensen, B.J.L., Pyne-O’Donnell, S., Plunkett, G., Froese, D.G., Hughes, P.D.M., Sigl, M., McConnell, J.R., Amesbury, M. J., Blackwell, P.G., van den Bogaard, C., Buck, C.E., Charman, D.J., Clague, J.J., Hall, V.A., Koch, J., Mackay, H., Mallon, G., McColl, L., Pilcher, J.R. 2014. Transatlantic distribution of the Alaskan White River Ash. Geology 42: 875-878.

Kidwell, S.M. 2015. Biology in the Anthropocene: challenges and insights from young fossil records. Proceedings of the National Academy of Sciences of the USA 112: 4922-4929.

King, M. 2003. The Penguin History of New Zealand. Penguin Books, Auckland, 570 pp.

Lane, C.S., Chorn, B.T., Johnson, T.C. 2013. Ash from the Toba supereruption in Lake Malawi shows no volcanic winter in East Africa at 75 ka. Proceedings of the National Academy of Sciences of the USA 110: 8025-8029.

Lewis S.L., Maslin, M.A. 2015. Defining the Anthropocene. Nature 519: 171-180.

Lowe, D.J. 2011. Tephrochronology and its application: a review. Quaternary Geochronology 6: 107-153.

Lowe, D.J., Pittari, A. 2014. An ashy septingentenarian: the Kaharoa tephra turns 700 (with notes on its volcanological, archaeological, and historical importance). Geoscience Society of New Zealand Newsletter 13: 35-46.

Macreadie, P.I., Allen, K., Kelaher, B.P., Ralph, P.J., Skilbeck, C.G. 2012. Paleoreconstruction of estuarine sediments reveal human-induced weakening of coastal carbon sinks. Global Change Biology 18: 891-901.

Magee, J.W., Miller, G.H., Spooner, N.G., Questiaux, D. 2004. A continuous 150,000 yr monsoon record from Lake Eyre, Australia: Insolation-forcing implications and unexpected Holocene failure. Geology 32: 885-888.

Marsh, G.P. 1864. Man and nature: or, physical geography as modified by human action. C. Scribner, New York.

Matthews, K.M. 1993. Radioactive Fallout in the South Pacific: A History. Part 3: Strontium-90 and Caesium-137 Deposition in New Zealand and Resulting Contamination of Milk. National Radiation Laboratory, Christchurch

McGlone, M.S. Wilmshurst, J.M. 1999. Dating initial Maori environmental impact in New Zealand. Quaternary International 59: 5-16.

Miller, G.H., Fogel, M.L., Magee, J.W., Gagan, M.K., Clarke, S.J., Johnson, B.J. 2005. Ecosystem collapse in Pleistocene Australia and a human role in megafaunal extinction. Science 309: 287-290.

Monastersky, R. 2015. The human age. Nature 519: 144-147.

Mooney, S.D., Harrison, S.P., Barlein, P.J., Daniau, A.-L, Stevenson, J., Brownlie, K.C., Buckman, S., Cupper, M., Luly, J., Black, M., Colhoun, E., D’Costa, D., Dodson, J., Haberle, S., Hope, G.S., Kershaw, P., Kenyon, C., McKenzie, M., Williams, N. 2011. Late Quaternary fire regimes of Australasia. Quaternary Science Reviews 30: 28-46.

Murphy, B.P., Williamson, G.J., Bowman, D.M.J.S. 2012. Did central Australian megafaunal extinction coincide with abrupt ecosystem collapse or gradual climate change? Global Ecology and Biogeography 21: 142-151.

Ogden, J., Basher, L., McGlone, M. 1998. Fire, forest regeneration and links with early human habitation: evidence from New Zealand. Annals of Botany 81: 687-696.

Oppenheimer, C. 2003. Climatic, environmental and human consequences of the largest known historical eruption: Tambora volcano (Indonesia) 1815. Progress in Physical Geography 27: 230-259.

Page, M.J., Trustrum, N.A., Brackley, H.L., Baisden, W.T. 2004. Erosion-related soil carbon fluxes in a pastoral steepland catchment, New Zealand. Agriculture, Ecosystems and Environment 103: 561–579.

Palmer, J., Turney, C., Hogg, A., Hilliam, N., Watson, M., van Sebille, E., Cowie, W., Jones, R., Petchey, F. 2013. The discovery of New Zealand’s oldest shipwreck – possible evidence of further Dutch exploration of the South Pacific. Journal of Archaeological Science 42: 435-441.

Park, G. 2013. ‘Swamps which might doubtless easily be drained’: swamp drainage and its impact on the indigenous. In: Pawson, E., Brooking, T. (eds), Making a New Land – Environmental Histories of New Zealand, new edition. Otago University Press, Dunedin, pp. 174-189.

Pawson, E., Brooking, T. (eds) 2013. Making a New Land – Environmental Histories of New Zealand, new edition. Otago University Press, Dunedin, 391 pp.

Perry, G.L.W., Wilmshurst, J.M., McGlone, M.S., McWethy, D.B., Whitlock, C. 2012. Explaining fire-driven landscape transformation during the Initial Burning Period of New Zealand’s prehistory. Global Change Biology 18: 1609-1621.

Perry, G.L.W., Wheeler, A.B., Wood, J.R., Wilmshurst, J.M. 2014. A high-precision chronology for the rapid extinction of New Zealand moa (Aves, Dinornithiformes). Quaternary Science Reviews 105: 126-135.

Price, G. J. 2012. Plio-Pleistocene climate and faunal change in central eastern Australia. Episodes-Newsmagazine of the International Union of Geological Sciences 35: 160-165.

Prideaux, G.J., Gully, G.A., Couzens, A.M.C., Ayliffe, L.K., Jankowski, N.R., Jacobs, Z. 2010. Timing and dynamics of Late Pleistocene mammal extinctions in southwestern Australia. Proceedings of the National Academy of Sciences of the USA 107: 22157-22162.

Rafter, T.A., Fergusson, G.J. 1957. “Atom Bomb Effect” – recent increase of carbon-14 content of the atmosphere and biosphere. Science 126: 557-558.

Rawlence D.J. 1984. A study of pigment and diatoms in a core from Lake Rotorua, North Island, New Zealand, with emphasis on recent history. Journal of the Royal Society of New Zealand 14: 119-132

Roberts, R.G., Jones, R. 2000. Chronologies of carbon and silica: evidence concerning the dating of the earliest human presence in northern Australia. In: Tobias, PV, Moggie-Cecchi, J, Raas, M.A., Doyle, G.A. (eds), Humanity from African Naissance to Coming Millennia, Colloquia in Human Biology and Palaeoanthropology, Firenze University Press, pp. 239-248.

Roberts, R.G., Flannery, T.F., Ayliffe, L.K., Yoshida, H., Olley, J.M., Prideaux, G.J., Laslett, G.M., Baynes, A., Smith, M.A., Jones, R., Smith, B.L. 2001. New ages for the last Australian megafauna: continent-wide extinction about 46,000 years ago. Science 292: 1888-1892.

Roberts, N. 2014. The Holocene: An Evironmental History, 3rd edition. Wiley-Blackwell, 376 pp.

Roebroeks, W., Villa, P. 2011. On the earliest evidence for habitual use of fire in Europe. Proceedings of the National Academy of Sciences of the USA 108: 5209-5214.

Ruddiman, W.F. 2013. Anthropocene. Annual Review of Earth and Planetary Sciences 41: 45-68.

Ruddiman W.F., Ellis, E.C., Kaplan, J.O., Fuller, D.Q. 2015. Defining the epoch we live in: is a formally designated “Anthropocene” a good idea? Science 348: 38-39.

Rule, S., Brook, B.W., Haberle, S.G., Turney, C.S.M., Kershaw, A.P., Johnson, C.N. 2012. The aftermath of megafaunal extinction: ecosystem transformation in Pleistocene Australia. Science 335: 1483-1486.

Schmidt, M., Higham, T.F.G. 1998. Sources of New Zealand’s East Polynesian culture revisited: the radiocarbon chronology of the Tairua archaeological site, New Zealand. The Journal of the Polynesian Society 107: 395-404.

Smith, B.D., Zeder, M.A. 2013. The onset of the Anthropocene. Anthropocene 4: 8-13.

Smith, V.C. 2014. Volcanic markers for dating the onset of the Anthropocene. Geological Society, London, Special Publication 395: 283-299.

Steffen, W., Crutzen, P.J., McNeill, J.R. 2007. The Anthropocene: are humans now overwhelming the great forces of Nature? Ambio 36: 614-621.

Steffen, W., Grinevald, J., Crutzen, P., McNeill, J. 2011. The Anthropocene: conceptual and historical perspectives. Philosophical Transactions of the Royal Society A 369: 842-867.

Steffen, W., Broadgate, W., Deutsch, L., Gaffney, O., Ludwig, C. 2015. The trajectory of the Anthropocene: the Great Acceleration. The Anthropocene Review 2: 81-98.

Stoppani A., 1873. Corso de Geologia Vol II. Milan. Bernardoni and Brigola. Italy.

Tennyson, A., Martinson, P. 2006. Extinct Birds of New Zealand. Te Papa Press, Wellington. ISBN: 9780909010-218.

Turney, C.S.M., Bird, M.I., Fifield, L.K., Roberts, R.G., Smith, M.A., Dortch, C.E., Grün, R., Lawson, E., Ayliffe, L.K., Miller, G.H., Dortch, J., Cresswell, R.G. 2001. Early human occupation at Devil’s Lair, southwestern Australia 50,000 years ago. Quaternary Research 55: 3-13.

Turney, C.S.M., Bird, M.I., Fifield, L.K., Kershaw, A.P., Cresswell, R.G., Santos, G.M., di Tada, M.L., Hausladen, P.A., Youping, Z., 2001b. Development of a robust 14C chronology for Lynch’s Crater (North Queensland, Australia) using different pretreatment strategies. Radiocarbon 43: 45-54.

Vince, G. 2014. Adventures in the Anthropocene: A Journey to the Heart of the Planet we Made. Milkweed editions, 465 pp., ISBN: 9780701187354.

Walker, M., Johnsen, S., Rasmussen, S.O., Popp, T., Steffensen, J.-P., Gibbard, P., Hoek, W., Lowe, J.J., Andrews, J., Björck, S.; Cwynar, L., Hughen, K., Kershaw, P., Kromer, B., Litt, T., Lowe, D.J., Nakagawa, T., Newnham, R.M., Schwander, J. 2009. Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records. Journal of Quaternary Science 24: 3-17.

Walker, M.J.C., Berkelhammer, M., Bjorck, S., Cwynar, L.C., Fisher, D.A., Long, A.J., Lowe, J.J., Newnham, R.M., Rasmussen, S.O., Weiss, H. 2012. Formal subdivision of the Holocene Series/Epoch: a discussion paper by a Working Group of INTIMATE (Integration of ice-core, marine and terrestrial records) and the Subcommission on Quaternary Stratigraphy (International Commission on Stratigraphy). Journal of Quaternary Science 27: 649-659.

Waters, C.N., Zalasiewicz, J.A., Williams, M., Ellis, M.A., Snelling, A.M. (eds) 2014. A stratigraphical basis for the Anthropocene. Geological Society, London, Special Publication 395: 1-321.

Wilmshurst, J.M. 1997. The impact of human settlement on vegetation and soil stability in Hawke’s Bay, New Zealand. New Zealand Journal of Botany 35: 97-111.

Wilmshurst, J.M., Higham T.F.G. 2004. Using rat-gnawed seeds to independently date the arrival of Pacific rats and humans to New Zealand. The Holocene 14: 801-806.

Wilmshurst, J.M., Anderson, A.J., Higham, T.F.G., Worthy, T.H. 2008. Dating the late prehistoric dispersal of Polynesians to New Zealand using the commmensal Pacific rat. Proceedings of the National Academy of Sciences of the USA 105: 7676-7680.

Wilmshurst, J.M., Hunt, T.L., Lipo, C.P. Anderson, A.J. 2011. High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia. Proceedings of the National Academy of Sciences of the USA 108: 1815-1820.

Wilmshurst, J.M., Moar, N.T., Wood, J.R., Bellingham, P.J., Findlater, A.M., Robinson, J.J., Stone, C. 2014. Use of pollen and ancient DNA as conservation baselines for offshore islands in New Zealand. Conservation Biology 28: 202-212.

Wolfe, A.P., Hobbs, W.O., Birks, H.H., Briner, J.P., Holmgren, S.U., Ingólfsson, Ó., Kaushal, S.S., Miller, G.H., Pagani, M., Saros, Jasmine E., Vinebrooke, R.D. 2013. Stratigraphic expressions of the Holocene-Anthropocene transition revealed in sediments from remote lakes. Earth Science Reviews 116: 17-34.

Wolff, E.W. 2011. Greenhouse gases in the Earth system: a palaeoclimate perspective. Philosophical Transactions of the Royal Society A 369: 2133-2147.

Wolff, E.W. 2014. Ice sheets and the Anthropocene. Geological Society, London, Special Publication 395: 255-263.

Wroe, S., Field, J.H., Archer, M., Grayson, D.K., Price, G.J., Louys, J., Faith, J.T, Webb, G.E., Davison, I., Mooney, S.D. 2013. Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea). Proceedings of the National Academy of Sciences of the USA 110: 8777-8781

Young H. 2015. The hitchiker’s guide to the Anthropocene: finding our place in the world we created. Science 347: 955.

Zalasiewicz, J., Williams, M., Haywood, A., Ellis, M. 2011. The Anthropocene: a new epoch of geological time? Philosophical Transactions of the Royal Society A 369: 835-841.

Zalasiewicz, J., Waters, C.N., Williams, M., Barnosky, A.D., Cearreta, A., Crutzen, P., Ellis, E., Ellis, M.A., Fairchild, I.J., Grinevald J., Haff, P.K., Hajdas, I., Leinfelder, R., McNeill, J., Odada, E.O., Poirier, C., Richter, D., Steffen, W., Summerhayes, C., Syvitski, J.P.M., Vidas, D., Wagreich, M., Wing, S.L., Wolfe, A.P., Zhisheng, A., Oreskes, N., 2015. When did the Anthropocene begin? A mid-twentieth century boundary level is stratigraphically optimal. Quaternary International, http://dx.doi.org/10.1016/j.quaint.2014.11.045.