Articles | Volume 11, issue 12
https://doi.org/10.5194/cp-11-1621-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/cp-11-1621-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Early warnings and missed alarms for abrupt monsoon transitions
Climate Change Research Centre and School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
F. Kwasniok
College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK
C. A. Boulton
College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
P. M. Cox
College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK
R. T. Jones
College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
T. M. Lenton
College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
C. S. M. Turney
Climate Change Research Centre and School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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The Last Interglacial (129–116 ka) experienced global temperatures and sea levels higher than today. The direct contribution of warmer conditions to global sea level (thermosteric) are uncertain. We report a global network of sea surface temperatures. We find mean global annual temperature anomalies of 0.2 ± 0.1˚C and an early maximum peak of 0.9 ± 0.1˚C. Our reconstruction suggests warmer waters contributed on average 0.08 ± 0.1 m and a peak contribution of 0.39 ± 0.1 m to global sea level.
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Zoë A. Thomas, Richard T. Jones, Chris J. Fogwill, Jackie Hatton, Alan N. Williams, Alan Hogg, Scott Mooney, Philip Jones, David Lister, Paul Mayewski, and Chris S. M. Turney
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Nicholas R. Golledge, Zoë A. Thomas, Richard H. Levy, Edward G. W. Gasson, Timothy R. Naish, Robert M. McKay, Douglas E. Kowalewski, and Christopher J. Fogwill
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Chris S. M. Turney, Christopher J. Fogwill, Jonathan G. Palmer, Erik van Sebille, Zoë Thomas, Matt McGlone, Sarah Richardson, Janet M. Wilmshurst, Pavla Fenwick, Violette Zunz, Hugues Goosse, Kerry-Jayne Wilson, Lionel Carter, Mathew Lipson, Richard T. Jones, Melanie Harsch, Graeme Clark, Ezequiel Marzinelli, Tracey Rogers, Eleanor Rainsley, Laura Ciasto, Stephanie Waterman, Elizabeth R. Thomas, and Martin Visbeck
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C. S. M. Turney, R. T. Jones, C. Fogwill, J. Hatton, A. N. Williams, A. Hogg, Z. A. Thomas, J. Palmer, S. Mooney, and R. W. Reimer
Clim. Past, 12, 189–200, https://doi.org/10.5194/cp-12-189-2016, https://doi.org/10.5194/cp-12-189-2016, 2016
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Earth Syst. Dynam., 15, 1483–1508, https://doi.org/10.5194/esd-15-1483-2024, https://doi.org/10.5194/esd-15-1483-2024, 2024
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Colin G. Jones, Fanny Adloff, Ben B. B. Booth, Peter M. Cox, Veronika Eyring, Pierre Friedlingstein, Katja Frieler, Helene T. Hewitt, Hazel A. Jeffery, Sylvie Joussaume, Torben Koenigk, Bryan N. Lawrence, Eleanor O'Rourke, Malcolm J. Roberts, Benjamin M. Sanderson, Roland Séférian, Samuel Somot, Pier Luigi Vidale, Detlef van Vuuren, Mario Acosta, Mats Bentsen, Raffaele Bernardello, Richard Betts, Ed Blockley, Julien Boé, Tom Bracegirdle, Pascale Braconnot, Victor Brovkin, Carlo Buontempo, Francisco Doblas-Reyes, Markus Donat, Italo Epicoco, Pete Falloon, Sandro Fiore, Thomas Frölicher, Neven S. Fučkar, Matthew J. Gidden, Helge F. Goessling, Rune Grand Graversen, Silvio Gualdi, José M. Gutiérrez, Tatiana Ilyina, Daniela Jacob, Chris D. Jones, Martin Juckes, Elizabeth Kendon, Erik Kjellström, Reto Knutti, Jason Lowe, Matthew Mizielinski, Paola Nassisi, Michael Obersteiner, Pierre Regnier, Romain Roehrig, David Salas y Mélia, Carl-Friedrich Schleussner, Michael Schulz, Enrico Scoccimarro, Laurent Terray, Hannes Thiemann, Richard A. Wood, Shuting Yang, and Sönke Zaehle
Earth Syst. Dynam., 15, 1319–1351, https://doi.org/10.5194/esd-15-1319-2024, https://doi.org/10.5194/esd-15-1319-2024, 2024
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Paul David Longden Ritchie, Chris Huntingford, and Peter Cox
EGUsphere, https://doi.org/10.5194/egusphere-2024-3023, https://doi.org/10.5194/egusphere-2024-3023, 2024
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Mark S. Williamson, Peter M. Cox, Chris Huntingford, and Femke J. M. M. Nijsse
Earth Syst. Dynam., 15, 829–852, https://doi.org/10.5194/esd-15-829-2024, https://doi.org/10.5194/esd-15-829-2024, 2024
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Antony Philip Emenyu, Thomas Pienkowski, Andrew M. Cunliffe, Timothy M. Lenton, and Tom Powell
EGUsphere, https://doi.org/10.5194/egusphere-2023-2531, https://doi.org/10.5194/egusphere-2023-2531, 2023
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Stephen P. Hesselbo, Aisha Al-Suwaidi, Sarah J. Baker, Giorgia Ballabio, Claire M. Belcher, Andrew Bond, Ian Boomer, Remco Bos, Christian J. Bjerrum, Kara Bogus, Richard Boyle, James V. Browning, Alan R. Butcher, Daniel J. Condon, Philip Copestake, Stuart Daines, Christopher Dalby, Magret Damaschke, Susana E. Damborenea, Jean-Francois Deconinck, Alexander J. Dickson, Isabel M. Fendley, Calum P. Fox, Angela Fraguas, Joost Frieling, Thomas A. Gibson, Tianchen He, Kat Hickey, Linda A. Hinnov, Teuntje P. Hollaar, Chunju Huang, Alexander J. L. Hudson, Hugh C. Jenkyns, Erdem Idiz, Mengjie Jiang, Wout Krijgsman, Christoph Korte, Melanie J. Leng, Timothy M. Lenton, Katharina Leu, Crispin T. S. Little, Conall MacNiocaill, Miguel O. Manceñido, Tamsin A. Mather, Emanuela Mattioli, Kenneth G. Miller, Robert J. Newton, Kevin N. Page, József Pálfy, Gregory Pieńkowski, Richard J. Porter, Simon W. Poulton, Alberto C. Riccardi, James B. Riding, Ailsa Roper, Micha Ruhl, Ricardo L. Silva, Marisa S. Storm, Guillaume Suan, Dominika Szűcs, Nicolas Thibault, Alfred Uchman, James N. Stanley, Clemens V. Ullmann, Bas van de Schootbrugge, Madeleine L. Vickers, Sonja Wadas, Jessica H. Whiteside, Paul B. Wignall, Thomas Wonik, Weimu Xu, Christian Zeeden, and Ke Zhao
Sci. Dril., 32, 1–25, https://doi.org/10.5194/sd-32-1-2023, https://doi.org/10.5194/sd-32-1-2023, 2023
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Mila Kim-Chau Fiona Ong, Fenna Blomsma, and Timothy Michael Lenton
EGUsphere, https://doi.org/10.5194/egusphere-2023-2361, https://doi.org/10.5194/egusphere-2023-2361, 2023
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Chris A. Boulton, Joshua E. Buxton, and Timothy M. Lenton
EGUsphere, https://doi.org/10.5194/egusphere-2023-2234, https://doi.org/10.5194/egusphere-2023-2234, 2023
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Early warning signals (EWS) of tipping points (TP), are used to detect resilience loss in the incumbent regime of ICEVs, towards an electric vehicle (EV) dominated state. View share of EV ads on a UK car selling platform shows evidence of approaching a TP, with results suggesting low-mid price ranges may have passed it, likely due to achieved price parity between EVs and non-EVs in sectors of the second-hand market, showing that EWS of positive TPs are possible in social-technological systems.
Rebecca M. Varney, Sarah E. Chadburn, Eleanor J. Burke, Simon Jones, Andy J. Wiltshire, and Peter M. Cox
Biogeosciences, 20, 3767–3790, https://doi.org/10.5194/bg-20-3767-2023, https://doi.org/10.5194/bg-20-3767-2023, 2023
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This study evaluates soil carbon projections during the 21st century in CMIP6 Earth system models. In general, we find a reduced spread of changes in global soil carbon in CMIP6 compared to the previous CMIP5 generation. The reduced CMIP6 spread arises from an emergent relationship between soil carbon changes due to change in plant productivity and soil carbon changes due to changes in turnover time. We show that this relationship is consistent with false priming under transient climate change.
Nina Raoult, Tim Jupp, Ben Booth, and Peter Cox
Earth Syst. Dynam., 14, 723–731, https://doi.org/10.5194/esd-14-723-2023, https://doi.org/10.5194/esd-14-723-2023, 2023
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Climate models are used to predict the impact of climate change. However, poorly constrained parameters used in the physics of the models mean that we simulate a large spread of possible future outcomes. We can use real-world observations to reduce the uncertainty of parameter values, but we do not have observations to reduce the spread of possible future outcomes directly. We present a method for translating the reduction in parameter uncertainty into a reduction in possible model projections.
Jakob Emanuel Deutloff, Hermann Held, and Timothy Michael Lenton
EGUsphere, https://doi.org/10.5194/egusphere-2023-1469, https://doi.org/10.5194/egusphere-2023-1469, 2023
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We investigate the probabilities of triggering climate tipping points under various emission scenarios and how they are altered by additional carbon emissions from tipping points within the Earth's carbon cycle. We find that even “middle of the road” emission scenarios are highly unsafe with regard to triggering climate tipping points. Under such scenarios, probabilities of triggering are increased substantially by carbon emissions from tipping points within the Earth's carbon cycle.
Paul D. L. Ritchie, Hassan Alkhayuon, Peter M. Cox, and Sebastian Wieczorek
Earth Syst. Dynam., 14, 669–683, https://doi.org/10.5194/esd-14-669-2023, https://doi.org/10.5194/esd-14-669-2023, 2023
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Complex systems can undergo abrupt changes or tipping points when external forcing crosses a critical level and are of increasing concern because of their severe impacts. However, tipping points can also occur when the external forcing changes too quickly without crossing any critical levels, which is very relevant for Earth’s systems and contemporary climate. We give an intuitive explanation of such rate-induced tipping and provide illustrative examples from natural and human systems.
Chris Huntingford, Peter M. Cox, Mark S. Williamson, Joseph J. Clarke, and Paul D. L. Ritchie
Earth Syst. Dynam., 14, 433–442, https://doi.org/10.5194/esd-14-433-2023, https://doi.org/10.5194/esd-14-433-2023, 2023
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Emergent constraints (ECs) reduce the spread of projections between climate models. ECs estimate changes to climate features impacting adaptation policy, and with this high profile, the method is under scrutiny. Asking
What is an EC?, we suggest they are often the discovery of parameters that characterise hidden large-scale equations that climate models solve implicitly. We present this conceptually via two examples. Our analysis implies possible new paths to link ECs and physical processes.
Taylor Smith, Ruxandra-Maria Zotta, Chris A. Boulton, Timothy M. Lenton, Wouter Dorigo, and Niklas Boers
Earth Syst. Dynam., 14, 173–183, https://doi.org/10.5194/esd-14-173-2023, https://doi.org/10.5194/esd-14-173-2023, 2023
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Multi-instrument records with varying signal-to-noise ratios are becoming increasingly common as legacy sensors are upgraded, and data sets are modernized. Induced changes in higher-order statistics such as the autocorrelation and variance are not always well captured by cross-calibration schemes. Here we investigate using synthetic examples how strong resulting biases can be and how they can be avoided in order to make reliable statements about changes in the resilience of a system.
Morgan Sparey, Peter Cox, and Mark S. Williamson
Biogeosciences, 20, 451–488, https://doi.org/10.5194/bg-20-451-2023, https://doi.org/10.5194/bg-20-451-2023, 2023
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Accurate climate models are vital for mitigating climate change; however, projections often disagree. Using Köppen–Geiger bioclimate classifications we show that CMIP6 climate models agree well on the fraction of global land surface that will change classification per degree of global warming. We find that 13 % of land will change climate per degree of warming from 1 to 3 K; thus, stabilising warming at 1.5 rather than 2 K would save over 7.5 million square kilometres from bioclimatic change.
Isobel M. Parry, Paul D. L. Ritchie, and Peter M. Cox
Earth Syst. Dynam., 13, 1667–1675, https://doi.org/10.5194/esd-13-1667-2022, https://doi.org/10.5194/esd-13-1667-2022, 2022
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Despite little evidence of regional Amazon rainforest dieback, many localised abrupt dieback events are observed in the latest state-of-the-art global climate models under anthropogenic climate change. The detected dieback events would still cause severe consequences for local communities and ecosystems. This study suggests that 7 ± 5 % of the northern South America region would experience abrupt downward shifts in vegetation carbon for every degree of global warming past 1.5 °C.
Rebecca M. Varney, Sarah E. Chadburn, Eleanor J. Burke, and Peter M. Cox
Biogeosciences, 19, 4671–4704, https://doi.org/10.5194/bg-19-4671-2022, https://doi.org/10.5194/bg-19-4671-2022, 2022
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Soil carbon is the Earth’s largest terrestrial carbon store, and the response to climate change represents one of the key uncertainties in obtaining accurate global carbon budgets required to successfully militate against climate change. The ability of climate models to simulate present-day soil carbon is therefore vital. This study assesses soil carbon simulation in the latest ensemble of models which allows key areas for future model development to be identified.
Philippa A. Higgins, Jonathan G. Palmer, Chris S. M. Turney, Martin S. Andersen, and Fiona Johnson
Clim. Past, 18, 1169–1188, https://doi.org/10.5194/cp-18-1169-2022, https://doi.org/10.5194/cp-18-1169-2022, 2022
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We studied eight New Zealand tree species and identified differences in their responses to large volcanic eruptions. The response is dependent on the species and how well it can tolerate stress, but substantial within-species differences are also observed depending on site factors, including altitude and exposure. This has important implications for tree-ring temperature reconstructions because site selection and compositing methods can change the magnitude of observed volcanic cooling.
Thomas S. Ball, Naomi E. Vaughan, Thomas W. Powell, Andrew Lovett, and Timothy M. Lenton
Geosci. Model Dev., 15, 929–949, https://doi.org/10.5194/gmd-15-929-2022, https://doi.org/10.5194/gmd-15-929-2022, 2022
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C-LLAMA is a simple model of the global food system operating at a country level from 2013 to 2050. The model begins with projections of diet composition and populations for each country, producing a demand for each food commodity and finally an agricultural land use in each country. The model can be used to explore the sensitivity of agricultural land use to various drivers within the food system at country, regional, and continental spatial aggregations.
Garry D. Hayman, Edward Comyn-Platt, Chris Huntingford, Anna B. Harper, Tom Powell, Peter M. Cox, William Collins, Christopher Webber, Jason Lowe, Stephen Sitch, Joanna I. House, Jonathan C. Doelman, Detlef P. van Vuuren, Sarah E. Chadburn, Eleanor Burke, and Nicola Gedney
Earth Syst. Dynam., 12, 513–544, https://doi.org/10.5194/esd-12-513-2021, https://doi.org/10.5194/esd-12-513-2021, 2021
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We model greenhouse gas emission scenarios consistent with limiting global warming to either 1.5 or 2 °C above pre-industrial levels. We quantify the effectiveness of methane emission control and land-based mitigation options regionally. Our results highlight the importance of reducing methane emissions for realistic emission pathways that meet the global warming targets. For land-based mitigation, growing bioenergy crops on existing agricultural land is preferable to replacing forests.
Andrew J. Wiltshire, Eleanor J. Burke, Sarah E. Chadburn, Chris D. Jones, Peter M. Cox, Taraka Davies-Barnard, Pierre Friedlingstein, Anna B. Harper, Spencer Liddicoat, Stephen Sitch, and Sönke Zaehle
Geosci. Model Dev., 14, 2161–2186, https://doi.org/10.5194/gmd-14-2161-2021, https://doi.org/10.5194/gmd-14-2161-2021, 2021
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Limited nitrogen availbility can restrict the growth of plants and their ability to assimilate carbon. It is important to include the impact of this process on the global land carbon cycle. This paper presents a model of the coupled land carbon and nitrogen cycle, which is included within the UK Earth System model to improve projections of climate change and impacts on ecosystems.
Chris S. M. Turney, Richard T. Jones, Nicholas P. McKay, Erik van Sebille, Zoë A. Thomas, Claus-Dieter Hillenbrand, and Christopher J. Fogwill
Earth Syst. Sci. Data, 12, 3341–3356, https://doi.org/10.5194/essd-12-3341-2020, https://doi.org/10.5194/essd-12-3341-2020, 2020
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The Last Interglacial (129–116 ka) experienced global temperatures and sea levels higher than today. The direct contribution of warmer conditions to global sea level (thermosteric) are uncertain. We report a global network of sea surface temperatures. We find mean global annual temperature anomalies of 0.2 ± 0.1˚C and an early maximum peak of 0.9 ± 0.1˚C. Our reconstruction suggests warmer waters contributed on average 0.08 ± 0.1 m and a peak contribution of 0.39 ± 0.1 m to global sea level.
Bettina K. Gier, Michael Buchwitz, Maximilian Reuter, Peter M. Cox, Pierre Friedlingstein, and Veronika Eyring
Biogeosciences, 17, 6115–6144, https://doi.org/10.5194/bg-17-6115-2020, https://doi.org/10.5194/bg-17-6115-2020, 2020
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Models from Coupled Model Intercomparison Project (CMIP) phases 5 and 6 are compared to a satellite data product of column-averaged CO2 mole fractions (XCO2). The previously believed discrepancy of the negative trend in seasonal cycle amplitude in the satellite product, which is not seen in in situ data nor in the models, is attributed to a sampling characteristic. Furthermore, CMIP6 models are shown to have made progress in reproducing the observed XCO2 time series compared to CMIP5.
Arthur P. K. Argles, Jonathan R. Moore, Chris Huntingford, Andrew J. Wiltshire, Anna B. Harper, Chris D. Jones, and Peter M. Cox
Geosci. Model Dev., 13, 4067–4089, https://doi.org/10.5194/gmd-13-4067-2020, https://doi.org/10.5194/gmd-13-4067-2020, 2020
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The Robust Ecosystem Demography (RED) model simulates cohorts of vegetation through mass classes. RED establishes a framework for representing demographic changes through competition, growth, and mortality across the size distribution of a forest. The steady state of the model can be solved analytically, enabling initialization. When driven by mean growth rates from a land-surface model, RED is able to fit the observed global vegetation map, giving a map of implicit mortality rates.
Femke J. M. M. Nijsse, Peter M. Cox, and Mark S. Williamson
Earth Syst. Dynam., 11, 737–750, https://doi.org/10.5194/esd-11-737-2020, https://doi.org/10.5194/esd-11-737-2020, 2020
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One of the key questions in climate science is how much more heating we will get for a given rise in carbon dioxide in the atmosphere. A new generation of models showed that this might be more than previously expected. Comparing the new models to observed temperature rise since 1970, we show that there is no need to revise the estimate upwards. Air pollution, whose effect on climate warming is poorly understood, stopped rising, allowing us to better constrain the greenhouse gas signal.
Simon Jones, Lucy Rowland, Peter Cox, Deborah Hemming, Andy Wiltshire, Karina Williams, Nicholas C. Parazoo, Junjie Liu, Antonio C. L. da Costa, Patrick Meir, Maurizio Mencuccini, and Anna B. Harper
Biogeosciences, 17, 3589–3612, https://doi.org/10.5194/bg-17-3589-2020, https://doi.org/10.5194/bg-17-3589-2020, 2020
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Non-structural carbohydrates (NSCs) are an important set of molecules that help plants to grow and respire when photosynthesis is restricted by extreme climate events. In this paper we present a simple model of NSC storage and assess the effect that it has on simulations of vegetation at the ecosystem scale. Our model has the potential to significantly change predictions of plant behaviour in global vegetation models, which would have large implications for predictions of the future climate.
Elisa Lovecchio and Timothy M. Lenton
Geosci. Model Dev., 13, 1865–1883, https://doi.org/10.5194/gmd-13-1865-2020, https://doi.org/10.5194/gmd-13-1865-2020, 2020
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We present here the newly developed BPOP box model. BPOP is aimed at studying the impact of large-scale changes in the biological pump, i.e. the cycle of production, export and remineralization of the marine organic matter, on the nutrient and oxygen concentrations in the shelf and open ocean. This model has been developed to investigate the global consequences of the evolution of larger and heavier phytoplankton cells but can be applied to a variety of past and future case studies.
Emma W. Littleton, Anna B. Harper, Naomi E. Vaughan, Rebecca J. Oliver, Maria Carolina Duran-Rojas, and Timothy M. Lenton
Geosci. Model Dev., 13, 1123–1136, https://doi.org/10.5194/gmd-13-1123-2020, https://doi.org/10.5194/gmd-13-1123-2020, 2020
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This study presents new functionality to represent bioenergy crops and harvests in JULES, a land surface model. Such processes must be explicitly represented before the environmental effects of large-scale bioenergy production can be fully evaluated, using Earth system modelling. This new functionality allows for many types of bioenergy plants and harvesting regimes to be simulated, such as perennial grasses, short rotation coppicing, and forestry rotations.
Jonathan R. Moore, Arthur P. K. Argles, Kai Zhu, Chris Huntingford, and Peter M. Cox
Biogeosciences, 17, 1013–1032, https://doi.org/10.5194/bg-17-1013-2020, https://doi.org/10.5194/bg-17-1013-2020, 2020
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The distribution of tree sizes across Amazonia can be fitted very well (for both trunk diameter and tree mass) by a simple equilibrium model assuming power law growth and size-independent mortality. We find tree growth to mirror some aspects of metabolic scaling theory and that there may be a trade-off between fast-growing, short-lived and longer-lived, slow-growing ones. Our Amazon mortality-to-growth ratio is very similar to US temperate forests, hinting at a universal property for trees.
Frank Kwasniok
Nonlin. Processes Geophys., 26, 195–209, https://doi.org/10.5194/npg-26-195-2019, https://doi.org/10.5194/npg-26-195-2019, 2019
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The stability properties as characterized by finite-time Lyapunov exponents are investigated in an intermediate-complexity atmospheric model. Firstly, the dominant patterns of collective excitation are identified by an empirical orthogonal function analysis of the fluctuation field of all of the finite-time Lyapunov exponents. Secondly, a large-deviation principle is established for all of the Lyapunov exponents and the large-deviation rate functions are estimated.
Karina E. Williams, Anna B. Harper, Chris Huntingford, Lina M. Mercado, Camilla T. Mathison, Pete D. Falloon, Peter M. Cox, and Joon Kim
Geosci. Model Dev., 12, 3207–3240, https://doi.org/10.5194/gmd-12-3207-2019, https://doi.org/10.5194/gmd-12-3207-2019, 2019
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Data from the First ISLSCP Field Experiment, 1987–1989, is used to assess how well the JULES land-surface model simulates water stress in tallgrass prairie vegetation. We find that JULES simulates a decrease in key carbon and water cycle variables during the dry period, as expected, but that it does not capture the shape of the diurnal cycle on these days. These results will be used to inform future model development as part of wider evaluation efforts.
Chris S. M. Turney, Helen V. McGregor, Pierre Francus, Nerilie Abram, Michael N. Evans, Hugues Goosse, Lucien von Gunten, Darrell Kaufman, Hans Linderholm, Marie-France Loutre, and Raphael Neukom
Clim. Past, 15, 611–615, https://doi.org/10.5194/cp-15-611-2019, https://doi.org/10.5194/cp-15-611-2019, 2019
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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 regional and global climate beyond the timescales accessible within the observational record.
Eleanor Rainsley, Chris S. M. Turney, Nicholas R. Golledge, Janet M. Wilmshurst, Matt S. McGlone, Alan G. Hogg, Bo Li, Zoë A. Thomas, Richard Roberts, Richard T. Jones, Jonathan G. Palmer, Verity Flett, Gregory de Wet, David K. Hutchinson, Mathew J. Lipson, Pavla Fenwick, Ben R. Hines, Umberto Binetti, and Christopher J. Fogwill
Clim. Past, 15, 423–448, https://doi.org/10.5194/cp-15-423-2019, https://doi.org/10.5194/cp-15-423-2019, 2019
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The New Zealand subantarctic islands, in the Pacific sector of the Southern Ocean, provide valuable records of past environmental change. We find that the Auckland Islands hosted a small ice cap around 384 000 years ago, but that there was little glaciation during the Last Glacial Maximum, around 21 000 years ago, in contrast to mainland New Zealand. This shows that the climate here is susceptible to changes in regional factors such as sea-ice expanse and the position of ocean fronts.
Amy J. Dougherty, Jeong-Heon Choi, Chris S. M. Turney, and Anthony Dosseto
Clim. Past, 15, 389–404, https://doi.org/10.5194/cp-15-389-2019, https://doi.org/10.5194/cp-15-389-2019, 2019
Ye Liu, Yongkang Xue, Glen MacDonald, Peter Cox, and Zhengqiu Zhang
Earth Syst. Dynam., 10, 9–29, https://doi.org/10.5194/esd-10-9-2019, https://doi.org/10.5194/esd-10-9-2019, 2019
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Climate regime shift during the 1980s identified by abrupt change in temperature, precipitation, etc. had a substantial impact on the ecosystem at different scales. Our paper identifies the spatial and temporal characteristics of the effects of climate variability, global warming, and eCO2 on ecosystem trends before and after the shift. We found about 15 % (20 %) of the global land area had enhanced positive trend (trend sign reversed) during the 1980s due to climate regime shift.
Florian Adolphi, Christopher Bronk Ramsey, Tobias Erhardt, R. Lawrence Edwards, Hai Cheng, Chris S. M. Turney, Alan Cooper, Anders Svensson, Sune O. Rasmussen, Hubertus Fischer, and Raimund Muscheler
Clim. Past, 14, 1755–1781, https://doi.org/10.5194/cp-14-1755-2018, https://doi.org/10.5194/cp-14-1755-2018, 2018
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The last glacial period was characterized by a number of rapid climate changes seen, for example, as abrupt warmings in Greenland and changes in monsoon rainfall intensity. However, due to chronological uncertainties it is challenging to know how tightly coupled these changes were. Here we exploit cosmogenic signals caused by changes in the Sun and Earth magnetic fields to link different climate archives and improve our understanding of the dynamics of abrupt climate change.
Qianyu Li, Xingjie Lu, Yingping Wang, Xin Huang, Peter M. Cox, and Yiqi Luo
Biogeosciences, 15, 6909–6925, https://doi.org/10.5194/bg-15-6909-2018, https://doi.org/10.5194/bg-15-6909-2018, 2018
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Land-surface models have been widely used to predict the responses of terrestrial ecosystems to climate change. A better understanding of model mechanisms that govern terrestrial ecosystem responses to rising atmosphere [CO2] is needed. Our study for the first time shows that the expansion of leaf area under rising [CO2] is the most important response for the stimulation of land carbon accumulation by a land-surface model: CABLE. Processes related to leaf area should be better calibrated.
Zoë A. Thomas, Richard T. Jones, Chris J. Fogwill, Jackie Hatton, Alan N. Williams, Alan Hogg, Scott Mooney, Philip Jones, David Lister, Paul Mayewski, and Chris S. M. Turney
Clim. Past, 14, 1727–1738, https://doi.org/10.5194/cp-14-1727-2018, https://doi.org/10.5194/cp-14-1727-2018, 2018
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We report a high-resolution study of a 5000-year-long peat record from the Falkland Islands. This area sensitive to the dynamics of the Amundsen Sea Low, which plays a major role in modulating the Southern Ocean climate. We find wetter, colder conditions between 5.0 and 2.5 ka due to enhanced southerly airflow, with the establishment of drier and warmer conditions from 2.5 ka to present. This implies more westerly airflow and the increased projection of the ASL onto the South Atlantic.
David I. Armstrong McKay and Timothy M. Lenton
Clim. Past, 14, 1515–1527, https://doi.org/10.5194/cp-14-1515-2018, https://doi.org/10.5194/cp-14-1515-2018, 2018
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This study uses statistical analyses to look for signs of declining resilience (i.e. greater sensitivity to small shocks) in the global carbon cycle and climate system across the Palaeocene–Eocene Thermal Maximum (PETM), a global warming event 56 Myr ago driven by rapid carbon release. Our main finding is that carbon cycle resilience declined in the 1.5 Myr beforehand (a time of significant volcanic emissions), which is consistent with but not proof of a carbon release tipping point at the PETM.
Anna B. Harper, Andrew J. Wiltshire, Peter M. Cox, Pierre Friedlingstein, Chris D. Jones, Lina M. Mercado, Stephen Sitch, Karina Williams, and Carolina Duran-Rojas
Geosci. Model Dev., 11, 2857–2873, https://doi.org/10.5194/gmd-11-2857-2018, https://doi.org/10.5194/gmd-11-2857-2018, 2018
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Dynamic global vegetation models are used for studying historical and future changes to vegetation and the terrestrial carbon cycle. JULES is a DGVM that represents the land surface in the UK Earth System Model. We compared simulated gross and net primary productivity of vegetation, vegetation distribution, and aspects of the transient carbon cycle to observational datasets. JULES was able to accurately reproduce many aspects of the terrestrial carbon cycle with the recent improvements.
Nicholas R. Golledge, Zoë A. Thomas, Richard H. Levy, Edward G. W. Gasson, Timothy R. Naish, Robert M. McKay, Douglas E. Kowalewski, and Christopher J. Fogwill
Clim. Past, 13, 959–975, https://doi.org/10.5194/cp-13-959-2017, https://doi.org/10.5194/cp-13-959-2017, 2017
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We investigated how the Antarctic climate and ice sheets evolved during a period of warmer-than-present temperatures 4 million years ago, during a time when the carbon dioxide concentration in the atmosphere was very similar to today's level. Using computer models to first simulate the climate, and then how the ice sheets responded, we found that Antarctica most likely lost around 8.5 m sea-level equivalent ice volume as both East and West Antarctic ice sheets retreated.
Chris Huntingford, Hui Yang, Anna Harper, Peter M. Cox, Nicola Gedney, Eleanor J. Burke, Jason A. Lowe, Garry Hayman, William J. Collins, Stephen M. Smith, and Edward Comyn-Platt
Earth Syst. Dynam., 8, 617–626, https://doi.org/10.5194/esd-8-617-2017, https://doi.org/10.5194/esd-8-617-2017, 2017
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Recent UNFCCC climate meetings have placed much emphasis on constraining global warming to remain below 2 °C. The 2015 Paris meeting went further and gave an aspiration to fulfil a 1.5 °C threshold. We provide a flexible set of algebraic global temperature profiles that stabilise to either target. This will potentially allow the climate research community to estimate local climatic implications for these temperature profiles, along with emissions trajectories to fulfil them.
Chris S.~M. Turney, Andrew Klekociuk, Christopher J. Fogwill, Violette Zunz, Hugues Goosse, Claire L. Parkinson, Gilbert Compo, Matthew Lazzara, Linda Keller, Rob Allan, Jonathan G. Palmer, Graeme Clark, and Ezequiel Marzinelli
The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-51, https://doi.org/10.5194/tc-2017-51, 2017
Revised manuscript not accepted
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We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
Chris S. M. Turney, Christopher J. Fogwill, Jonathan G. Palmer, Erik van Sebille, Zoë Thomas, Matt McGlone, Sarah Richardson, Janet M. Wilmshurst, Pavla Fenwick, Violette Zunz, Hugues Goosse, Kerry-Jayne Wilson, Lionel Carter, Mathew Lipson, Richard T. Jones, Melanie Harsch, Graeme Clark, Ezequiel Marzinelli, Tracey Rogers, Eleanor Rainsley, Laura Ciasto, Stephanie Waterman, Elizabeth R. Thomas, and Martin Visbeck
Clim. Past, 13, 231–248, https://doi.org/10.5194/cp-13-231-2017, https://doi.org/10.5194/cp-13-231-2017, 2017
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The Southern Ocean plays a fundamental role in global climate but suffers from a dearth of observational data. As the Australasian Antarctic Expedition 2013–2014 we have developed the first annually resolved temperature record using trees from subantarctic southwest Pacific (52–54˚S) to extend the climate record back to 1870. With modelling we show today's high climate variability became established in the ~1940s and likely driven by a Rossby wave response originating from the tropical Pacific.
Christopher J. Fogwill, Erik van Sebille, Eva A. Cougnon, Chris S. M. Turney, Steve R. Rintoul, Benjamin K. Galton-Fenzi, Graeme F. Clark, E. M. Marzinelli, Eleanor B. Rainsley, and Lionel Carter
The Cryosphere, 10, 2603–2609, https://doi.org/10.5194/tc-10-2603-2016, https://doi.org/10.5194/tc-10-2603-2016, 2016
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Here we report new data from in situ oceanographic surveys and high-resolution ocean modelling experiments in the Commonwealth Bay region of East Antarctica, where in 2010 there was a major reconfiguration of the regional icescape due to the collision of the 97 km long iceberg B09B with the Mertz Glacier tongue. Here we compare post-calving observations with high-resolution ocean modelling which suggest that this reconfiguration has led to the development of a new polynya off Commonwealth Bay.
Steven J. Phipps, Christopher J. Fogwill, and Christian S. M. Turney
The Cryosphere, 10, 2317–2328, https://doi.org/10.5194/tc-10-2317-2016, https://doi.org/10.5194/tc-10-2317-2016, 2016
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We explore the effects of melting of the East Antarctic Ice Sheet on the Southern Ocean. Using a climate model, we find that melting changes the ocean circulation and causes warming of more than 1 °C at depth. We also discover the potential existence of a "domino effect", whereby the initial warming spreads westwards around the Antarctic continent. Melting of just one sector could therefore destabilise the wider Antarctic Ice Sheet, leading to substantial increases in global sea level.
Nina M. Raoult, Tim E. Jupp, Peter M. Cox, and Catherine M. Luke
Geosci. Model Dev., 9, 2833–2852, https://doi.org/10.5194/gmd-9-2833-2016, https://doi.org/10.5194/gmd-9-2833-2016, 2016
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We present a set of "optimal" parameter values used to describe the influence of vegetation in a numerical climate model, and the software suite that we developed to find it. Observational data from ~ 100 locations were used, and the optimal parameters improve the fit in 90 % of the locations. The new parameter values will allow the climate model to give better predictions, and our software should prove useful in future calibrations.
Sebastian Bathiany, Bregje van der Bolt, Mark S. Williamson, Timothy M. Lenton, Marten Scheffer, Egbert H. van Nes, and Dirk Notz
The Cryosphere, 10, 1631–1645, https://doi.org/10.5194/tc-10-1631-2016, https://doi.org/10.5194/tc-10-1631-2016, 2016
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We examine if a potential "tipping point" in Arctic sea ice, causing abrupt and irreversible sea-ice loss, could be foreseen with statistical early warning signals. We assess this idea by using several models of different complexity. We find robust and consistent trends in variability that are not specific to the existence of a tipping point. While this makes an early warning impossible, it allows to estimate sea-ice variability from only short observational records or reconstructions.
Anna B. Harper, Peter M. Cox, Pierre Friedlingstein, Andy J. Wiltshire, Chris D. Jones, Stephen Sitch, Lina M. Mercado, Margriet Groenendijk, Eddy Robertson, Jens Kattge, Gerhard Bönisch, Owen K. Atkin, Michael Bahn, Johannes Cornelissen, Ülo Niinemets, Vladimir Onipchenko, Josep Peñuelas, Lourens Poorter, Peter B. Reich, Nadjeda A. Soudzilovskaia, and Peter van Bodegom
Geosci. Model Dev., 9, 2415–2440, https://doi.org/10.5194/gmd-9-2415-2016, https://doi.org/10.5194/gmd-9-2415-2016, 2016
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Dynamic global vegetation models (DGVMs) are used to predict the response of vegetation to climate change. We improved the representation of carbon uptake by ecosystems in a DGVM by including a wider range of trade-offs between nutrient allocation to photosynthetic capacity and leaf structure, based on observed plant traits from a worldwide data base. The improved model has higher rates of photosynthesis and net C uptake by plants, and more closely matches observations at site and global scales.
Stefan C. Dekker, Margriet Groenendijk, Ben B. B. Booth, Chris Huntingford, and Peter M. Cox
Earth Syst. Dynam., 7, 525–533, https://doi.org/10.5194/esd-7-525-2016, https://doi.org/10.5194/esd-7-525-2016, 2016
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Our analysis allows us to infer maps of changing plant water-use efficiency (WUE) for 1901–2010, using atmospheric observations of temperature, humidity and CO2. Our estimated increase in global WUE is consistent with the tree-ring and eddy covariance data, but much larger than the historical WUE increases simulated by Earth System Models (ESMs). We therefore conclude that the effects of increasing CO2 on plant WUE are significantly underestimated in the latest climate projections.
Timothy M. Lenton, Peter-Paul Pichler, and Helga Weisz
Earth Syst. Dynam., 7, 353–370, https://doi.org/10.5194/esd-7-353-2016, https://doi.org/10.5194/esd-7-353-2016, 2016
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We identify six past revolutions in energy input and material cycling in Earth and human history. We find that human energy use has now reached a magnitude comparable to the biosphere, and conclude that a prospective sustainability revolution will require scaling up new solar energy technologies and the development of much more efficient material recycling systems. Our work was inspired by recognising the connections between Earth system science and industrial ecology at the "LOOPS" workshop.
Mark S. Williamson, Sebastian Bathiany, and Timothy M. Lenton
Earth Syst. Dynam., 7, 313–326, https://doi.org/10.5194/esd-7-313-2016, https://doi.org/10.5194/esd-7-313-2016, 2016
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We find early warnings of abrupt changes in complex dynamical systems such as the climate where the usual early warning indicators do not work. In particular, these are systems that are periodically forced, for example by the annual cycle of solar insolation. We show these indicators are good theoretically in a general setting then apply them to a specific system, that of the Arctic sea ice, which has been conjectured to be close to such a tipping point. We do not find evidence of it.
C. S. M. Turney, R. T. Jones, C. Fogwill, J. Hatton, A. N. Williams, A. Hogg, Z. A. Thomas, J. Palmer, S. Mooney, and R. W. Reimer
Clim. Past, 12, 189–200, https://doi.org/10.5194/cp-12-189-2016, https://doi.org/10.5194/cp-12-189-2016, 2016
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Southern Hemisphere westerly airflow is considered a major driver of Southern Ocean and global climate. Observational records, however, are limited. Here we present a new Falkland Islands record that exploits "exotic" South America pollen and charcoal to reconstruct changing airflow. We find stronger winds 2000–1000 cal. yr BP, associated with increased burning, and a 250-year periodicity, suggesting solar forcing. Our results have important implications for understanding late Holocene climates.
C. S. M. Turney, C. J. Fogwill, A. R. Klekociuk, T. D. van Ommen, M. A. J. Curran, A. D. Moy, and J. G. Palmer
The Cryosphere, 9, 2405–2415, https://doi.org/10.5194/tc-9-2405-2015, https://doi.org/10.5194/tc-9-2405-2015, 2015
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Recent trends in ocean circulation, sea ice and climate over the Southern Ocean and Antarctica are highly complex. Here we report a new snow core from the South Pole alongside reanalysis of 20th century global atmospheric circulation. We demonstrate for the first time that atmospheric pressure anomalies in the mid-latitudes act as "gatekeepers" to meridional exchange over continental Antarctica, modulated by the tropical Pacific, with potentially significant impacts on surface mass balance.
S. E. Chadburn, E. J. Burke, R. L. H. Essery, J. Boike, M. Langer, M. Heikenfeld, P. M. Cox, and P. Friedlingstein
The Cryosphere, 9, 1505–1521, https://doi.org/10.5194/tc-9-1505-2015, https://doi.org/10.5194/tc-9-1505-2015, 2015
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In this paper we use a global land-surface model to study the dynamics of Arctic permafrost. We examine the impact of new and improved processes in the model, namely soil depth and resolution, organic soils, moss and the representation of snow. These improvements make the simulated soil temperatures and thaw depth significantly more realistic. Simulations under future climate scenarios show that permafrost thaws more slowly in the new model version, but still a large amount is lost by 2100.
S. Chadburn, E. Burke, R. Essery, J. Boike, M. Langer, M. Heikenfeld, P. Cox, and P. Friedlingstein
Geosci. Model Dev., 8, 1493–1508, https://doi.org/10.5194/gmd-8-1493-2015, https://doi.org/10.5194/gmd-8-1493-2015, 2015
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Permafrost, ground that is frozen for 2 or more years, is found extensively in the Arctic. It stores large quantities of carbon, which may be released under climate warming, so it is important to include it in climate models. Here we improve the representation of permafrost in a climate model land-surface scheme, both in the numerical representation of soil and snow, and by adding the effects of organic soils and moss. Site simulations show significantly improved soil temperature and thaw depth.
A. Rouillard, G. Skrzypek, S. Dogramaci, C. Turney, and P. F. Grierson
Hydrol. Earth Syst. Sci., 19, 2057–2078, https://doi.org/10.5194/hess-19-2057-2015, https://doi.org/10.5194/hess-19-2057-2015, 2015
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We reconstructed a 100-year monthly history of flooding and drought of a large wetland in arid northwest Australia, using hydroclimatic data calibrated against 25 years of satellite images. Severe and intense regional rainfall, as well as the sequence of events, determined surface water expression on the floodplain. While inter-annual variability was high, changes to the flood regime over the last 20 years suggest the wetland may become more persistent in response to the observed rainfall trend.
L. Kwiatkowski, A. Yool, J. I. Allen, T. R. Anderson, R. Barciela, E. T. Buitenhuis, M. Butenschön, C. Enright, P. R. Halloran, C. Le Quéré, L. de Mora, M.-F. Racault, B. Sinha, I. J. Totterdell, and P. M. Cox
Biogeosciences, 11, 7291–7304, https://doi.org/10.5194/bg-11-7291-2014, https://doi.org/10.5194/bg-11-7291-2014, 2014
A. M. Foley, D. Dalmonech, A. D. Friend, F. Aires, A. T. Archibald, P. Bartlein, L. Bopp, J. Chappellaz, P. Cox, N. R. Edwards, G. Feulner, P. Friedlingstein, S. P. Harrison, P. O. Hopcroft, C. D. Jones, J. Kolassa, J. G. Levine, I. C. Prentice, J. Pyle, N. Vázquez Riveiros, E. W. Wolff, and S. Zaehle
Biogeosciences, 10, 8305–8328, https://doi.org/10.5194/bg-10-8305-2013, https://doi.org/10.5194/bg-10-8305-2013, 2013
G. Colbourn, A. Ridgwell, and T. M. Lenton
Geosci. Model Dev., 6, 1543–1573, https://doi.org/10.5194/gmd-6-1543-2013, https://doi.org/10.5194/gmd-6-1543-2013, 2013
V. N. Livina and T. M. Lenton
The Cryosphere, 7, 275–286, https://doi.org/10.5194/tc-7-275-2013, https://doi.org/10.5194/tc-7-275-2013, 2013
Related subject area
Subject: Feedback and Forcing | Archive: Terrestrial Archives | Timescale: Pleistocene
Sub-decadal- to decadal-scale climate cyclicity during the Holsteinian interglacial (MIS 11) evidenced in annually laminated sediments
A. Koutsodendris, A. Brauer, H. Pälike, U. C. Müller, P. Dulski, A. F. Lotter, and J. Pross
Clim. Past, 7, 987–999, https://doi.org/10.5194/cp-7-987-2011, https://doi.org/10.5194/cp-7-987-2011, 2011
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Short summary
Using a combination of speleothem records and model simulations of the East Asian Monsoon over the penultimate glacial cycle, we search for early warning signals of past tipping points. We detect a characteristic slower response to perturbations prior to an abrupt monsoon shift at the glacial termination; however, we do not detect these signals in the preceding shifts. Our results have important implications for detecting tipping points in palaeoclimate records outside glacial terminations.
Using a combination of speleothem records and model simulations of the East Asian Monsoon over...