Chris S. M. Turney

University of Technology Sydney | UTS

The role of natural selection in shaping biological diversity is an area of intense interest in modern biology. To date, studies of positive selection have primarily relied on genomic datasets from contemporary populations, which are susceptible to confounding factors associated with complex and often unknown aspects of population history. In parti...

Context. Populations of the threatened plant Acacia dangarensis at Mount Dangar (Hunter Valley, New South Wales) may best be managed by recognising centurial, rather than decadal, change in habitat. Aim. Multiple data sources have been used to explore the hypothesis that above-ground presence of A. dangarensis is driven by centurial-scale cycles in...

Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maxi...

The initial peopling of the remote Pacific islands was one of the greatest migrations in human history, beginning three millennia ago by Lapita cultural groups. The spread of Lapita out of an ancestral Asian homeland is a dominant narrative in the origins of Pacific peoples, and although Island New Guinea has long been recognized as a springboard f...

Proxy records from across the Southern Hemisphere show significant local to regional scale variability in climatic and environmental conditions during late Marine Isotope Stage 3 and early Marine Isotope Stage 2, prior to the global last glacial maximum (LGM; 26.5–19.0 kyr). Although not necessarily synchronous across the hemisphere, the regional s...

Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maxi...

Antarctic sea-ice forms a complex and dynamic system that drives many ecological processes in the Southern Ocean. Sea-ice microalgae and their associated microbial communities are understood to influence nutrient flow and allocation in marine polar environments. Sea-ice microalgae and their microbiota can have high seasonal and regional (>1000 km ²...

Wetland sediments are valuable archives of environmental change but can be challenging to date. Terrestrial macrofossils are often sparse, resulting in radiocarbon ( ¹⁴ C) dating of less desirable organic fractions. An alternative approach for capturing changes in atmospheric ¹⁴ C is the use of terrestrial microfossils. We ¹⁴ C date pollen microfos...

The authors regret that the printed version of the above article contained a transcription error in the m/z 1048 peak area column for the branched GDGTs (Table S2). This error affected the GDGT-inferred summer air temperature presented in Figs. 3, 4 and 5, and some of the calibrations presented Fig. S2. The GDGT-inferred temperatures have been reca...

Streamflow in Australia’s northern rivers has been steadily increasing since the 1970s, most likely due to increased intensity in the Indo‐Australian monsoon. However, because of limited data availability, it is hard to assess this recent trend and therefore contextualize potential future climatic changes. In this study, we used a network of 63 pre...

Much of our knowledge about the impacts of volcanic events on climate comes from proxy records. However, little is known about the impact of volcanoes on trees from the Southern Hemisphere. We investigated whether volcanic signals could be identified in ring widths from eight New Zealand dendrochronological species, using superposed epoch analysis....

This paper presents a compilation of atmospheric radiocarbon for the period 1950–2019, derived from atmospheric CO 2 sampling and tree rings from clean-air sites. Following the approach taken by Hua et al. (2013), our revised and extended compilation consists of zonal, hemispheric and global radiocarbon ( ¹⁴ C) data sets, with monthly data sets for...

Our paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks’ assertions of misrepresentation are...

Our study on the exact timing and the potential climatic, environmental, and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated the hypothesis that geomagnetism represents an unrecognized driver in environmental and evolutionary change. It is important for this hypothesis to be tested with new data, and encouragingly, no...

Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maxi...

Radiocarbon dating is the most widely applied and reliable dating technique for providing chronological control during Marine Isotope Stage 3 (MIS3; ∼60–27 cal kyr BP). Past variations in the atmospheric concentration of radiocarbon mean a calibration curve is required. IntCal20 and SHCal20 calibration curves covering MIS3 are presently largely bas...

Plain Language Summary Ice sheets can respond to climatic warming in complex ways, commonly only reaching a new state of balance many hundreds or even thousands of years after the initial change in climate has occurred. Here, we investigate how the Antarctic Ice Sheet (AIS) responded to a period of prolonged warmer‐than‐present climate that took pl...

The evolutionarily recent dispersal of Anatomically Modern Humans (AMH) out of Africa and across Eurasia provides an opportunity to study rapid genetic adaptation to multiple new environments. Genomic analyses of modern human populations have detected limited signals of strong selection such as hard sweeps, but genetic admixture between populations...

Cryptotephra deposits (microscopic volcanic ash) are important geochronological tools that can be used to synchronize records of past environmental change. Here we report a distal cryptotephra from a Holocene peat sequence (Canopus Hill) in the Falkland Islands, in the South Atlantic. Using geochemical analysis (major- and trace-element) of individ...

The alpine area of the Australian mainland is highly sensitive to climate and environmental change, and potentially vulnerable to ecosystem tipping points. Over the next two decades the Australian alpine region is predicted to experience temperature increases of at least 1 °C, coupled with a substantial decrease in snow cover. Extending the short i...

The Chronos ¹⁴ Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeologica...

The hominin fossil record of Island Southeast Asia (ISEA) indicates that at least two endemic ‘super-archaic’ species—Homo luzonensis and H. floresiensis—were present around the time anatomically modern humans arrived in the region >50,000 years ago. Intriguingly, contemporary human populations across ISEA carry distinct genomic traces of ancient i...

Emerging evidence suggests retreat of the Antarctic Ice Sheet (AIS) can persist considerably longer than the duration of the forcing. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and responses on century and longer timescales. New data from Iceberg Alley identifies eight retreat phases after the l...

Satellite observations offering detailed records of global environmental change are only available from 1979. Emerging studies combining high-quality instrumental and natural observations highlight that the Earth system experienced a substantial shift across the mid-20th century, one that appears to have taken place before the Great Acceleration of...

Reversing the field Do terrestrial geomagnetic field reversals have an effect on Earth's climate? Cooper et al. created a precisely dated radiocarbon record around the time of the Laschamps geomagnetic reversal about 41,000 years ago from the rings of New Zealand swamp kauri trees. This record reveals a substantial increase in the carbon-14 content...

Supplementary Material for 'A global environmental crisis 42,000 years ago' Geological archives record multiple reversals of Earth’s magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the...

The dynamics of the Late Glacial (LG) have been demonstrated by numerous records from the Northern Hemisphere (NH) and far fewer from the Southern Hemisphere (SH). SH paleoclimate records reveal a general warming trend, interrupted by a deglaciation pause (ACR: Antarctic Cold Reversal, ~14,700-13,000 cal BP). Here we present decadal tree-ring stabl...

A valuable analogue for assessing Earth's sensitivity to warming is the Last Interglacial (LIG; 129–116 ka), when global temperatures (0 to +2 ∘C) and mean sea level (+6 to 11 m) were higher than today. The direct contribution of warmer conditions to global sea level (thermosteric) is uncertain. We report here a global network of LIG sea surface te...

Plain Language Summary South Pacific island communities experience significant variability in their rainfall between seasons, across years, and between decades. This variability is due to changes in the average position and intensity of the South Pacific Convergence Zone (SPCZ), the largest rain belt in the Southern Hemisphere. The SPCZ tends to mo...

Previous studies have suggested that the Late Glacial period (LG; ∼14 600–11 700 cal BP) was characterised by abrupt and extreme climate variability over the European sector of the North Atlantic. The limited number of precisely dated, high-resolution proxy records, however, restricts our understanding of climate dynamics through the LG. Here, we p...

Early researchers of radiocarbon levels in Southern Hemisphere tree rings identified a variable North-South hemispheric offset, necessitating construction of a separate radiocarbon calibration curve for the South. We present here SHCal20, a revised calibration curve from 0-55,000 cal BP, based upon SHCal13 and fortified by the addition of 14 new tr...

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 11 m) relative to present day. LIG sea level...

The hominin fossil record of Island Southeast Asia (ISEA) indicates that at least two endemic super-archaic species, Homo luzonensis and H. floresiensis, were present around the time anatomically modern humans (AMH) arrived in the region >50,000 years ago. Contemporary human populations carry signals consistent with interbreeding events with Deniso...

The Southern Ocean occupies 14% of the Earth’s surface and plays a fundamental role in the global carbon cycle and climate. It provides a direct connection to the deep ocean carbon reservoir through biogeochemical processes that include surface primary productivity, remineralization at depth and the upwelling of carbon-rich water masses. However, t...

The role of selection in shaping genetic diversity in natural populations is an area of intense interest in modern biology, especially the characterization of adaptive loci. Within humans, the rapid increase in genomic information has produced surprisingly few well-defined adaptive loci, promoting the view that recent human adaptation involved nume...

This study investigates if Blue Intensity (BI) parameters are capable of capturing enhanced climatic signals from a key New Zealand dendrochronological species when compared to ring-width (RW) measurements. Three BI parameters (earlywood mean, latewood mean and maximum latewood) recorded generally superior correlations to temperature than conventio...

Irreversible shifts of large-scale components of the Earth system (so-called ‘tipping elements’) on policy-relevant timescales are a major source of uncertainty for projecting the impacts of future climate change. The high latitudes are particularly vulnerable to positive feedbacks that amplify change through atmosphere-ocean-ice interactions. Unfo...

Radiocarbon (C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric C concentration. Although calibration curves are constructed from independently dated archives, they inva...

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level...

Abstract. A valuable analogue for assessing Earth’s sensitivity to warming is the Last Interglacial (LIG; 129–116 kyr), when global temperatures (0−+2 °C) and mean sea level (+6–11 m) were higher than today. The direct contribution of warmer conditions to global sea level (thermosteric) are uncertain. We report here a global network of LIG sea surf...

The sub-Antarctic islands of New Zealand are biodiversity hotspots in the Southern Ocean, containing numerous endemic species and providing breeding grounds for seabirds and marine mammals. However, due to their remoteness and harsh environments, many of their marine ecosystems are relatively unexplored and potentially at risk from alien invasive s...

Campbell Island, which is 600 km south of New Zealand, has the southernmost tree line in this ocean sector. Directly under the maximum of the westerlies, the island is sensitive to changes in wind strength and direction. Pollen records from three peat cores spanning the tree line ecotone provide a 17,000-year history of vegetation change, temperatu...

The Taupo eruption deposit is an isochronous marker bed that spans much of New Zealand’s North Island and pre-dates human arrival. Holdaway et al. (2018, Nature Comms 9, 4110) propose that the current Taupo eruption date is inaccurate and that the eruption occurred “…decades to two centuries…” after the published wiggle-match estimate of 232 ± 10 C...

Reconstructing past sea levels can help constrain uncertainties surrounding the rate of change, magnitude, and impacts of the projected increase through the 21 st century. Of significance is the mid-Holocene relative sea-level highstand in tectonically stable and remote (far-field) locations from major ice sheets. The east coast of Australia provid...

Precise radiocarbon ( ¹⁴ C) dating of sedimentary sequences is important for developing robust chronologies of environmental change, but sampling of suitable components can be challenging in highly dynamic landscapes. Here we investigate radiocarbon determinations of different peat size fractions from six peat sites, representing a range of geomorp...

Chris Turney applauds a book on carbon-14 and its key applications in archaeology, climatology and oceanography. Chris Turney applauds a book on carbon-14 and its key applications in archaeology, climatology and oceanography. Sample being removed from bone for carbon dating using accelerator mass spectrometry

Determining the feedbacks that modulate Southern Ocean carbon dynamics is key to understanding past and future climate. The global pause in rising atmospheric CO2 during the period of mid- to high-latitude southern surface cooling known as the Antarctic Cold Reversal (ACR, 14,700-12,700 years ago) provides an opportunity to disentangle competing in...

This research investigates two factors influencing the ability of tree-ring data to provide accurate ¹⁴ C calibration information: the fitness and rigor of the statistical model used to combine the data into a curve; and the accuracy, precision and reproducibility of the component ¹⁴ C data sets. It presents a new Bayesian spline method for calibra...

New research at the Keele University ICELAB is uncovering plankton in Antarctic ice. Innovative use of both fluorescent organic matter (fOM) spectroscopy and imaging flow cytometry (IFC) links ice-bound plankton and fluorescing tryptophan-like substances (TRYLIS) with sea ice dynamics in the Weddell and Ross Seas. This technique offers a means to g...

The formation of Antarctic Bottom Water (AABW) within the Weddell Sea Embayment (WSE) plays a major role in the Southern Ocean circulation and its interaction with the global climate system. Increasing importance is attributed to AABW in moderating the Earth's heat and carbon flux. However, historic trends in AABW formation are not well understood...

This PAGES (Past Global Changes) 2k (climate of the past 2000 years working group) special issue of Climate of the Past brings together the latest understanding of regional change and impacts from PAGES 2k groups across a range of proxies and regions. The special issue has emerged from a need to determine the magnitude and rate of change of regiona...

The New Zealand subantarctic islands of Auckland and Campbell, situated between the subtropical front and the Antarctic Convergence in the Pacific sector of the Southern Ocean, provide valuable terrestrial records from a globally important climatic region. Whilst the islands show clear evidence of past glaciation, the timing and mechanisms behind P...

Records of past sea levels, storms, and their impacts on coastlines are crucial for forecasting and managing future changes resulting from anthropogenic global warming. Coastal barriers that have prograded over the Holocene preserve within their accreting sands a history of storm erosion and changes in sea level. High-resolution geophysics, geochro...

Botryococcus braunii is a colonial microalga that appears early in the fossil record and is a sensitive proxy of environmental and hydroclimatic conditions. Palaeozoic Botryococcus fossils which contribute up to 90% of oil shales and approximately 1% of crude oil, co-localise with diagnostic geolipids from the degradation of source-signature hydroc...

Understanding extinction events requires an unbiased record of the chronology and ecology of victims and survivors. The rhinoceros Elasmotherium sibiricum, known as the ‘Siberian unicorn’, was believed to have gone extinct around 200,000 years ago—well before the late Quaternary megafaunal extinction event. However, no absolute dating, genetic anal...

The Southern Ocean plays a fundamental role in regulating global atmospheric CO2 levels, yet the underlying processes and feedbacks that control the carbon cycle during climate transitions remain unclear. Following the Last Glacial Termination (LGT), the rapid rise in atmospheric CO2 was interrupted by an enigmatic 1,900-year plateau during a perio...