Articles | Volume 14, issue 12
https://doi.org/10.5194/cp-14-2011-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-14-2011-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Dec 2018
Research article |
| 18 Dec 2018
| 18 Dec 2018
Long-term deglacial permafrost carbon dynamics in MPI-ESM
Thomas Schneider von Deimling
CORRESPONDING AUTHOR
Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg,
Germany
now at: Alfred Wegener Institute Helmholtz Centre for Polar and
Marine Research, 14473 Potsdam, Germany
Thomas Kleinen
Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg,
Germany
Gustaf Hugelius
Department of Physical Geography, Stockholm University, 10693,
Stockholm, Sweden
Bolin Climate Research Centre, Stockholm University, 10693,
Stockholm, Sweden
Christian Knoblauch
Institute of Soil Science, Universität Hamburg, Allende-Platz 2,
20146 Hamburg, Germany
Christian Beer
Department of Environmental Science and Analytical Chemistry,
Stockholm University, 10691 Stockholm, Sweden
Bolin Climate Research Centre, Stockholm University, 10693,
Stockholm, Sweden
Victor Brovkin
Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg,
Germany
Related authors
Moritz Langer, Jan Nitzbon, Brian Groenke, Lisa-Marie Assmann, Thomas Schneider von Deimling, Simone Maria Stuenzi, and Sebastian Westermann
The Cryosphere, 18, 363–385, https://doi.org/10.5194/tc-18-363-2024, https://doi.org/10.5194/tc-18-363-2024, 2024
Short summary
Short summary
Using a model that can simulate the evolution of Arctic permafrost over centuries to millennia, we find that post-industrialization permafrost warming has three "hotspots" in NE Canada, N Alaska, and W Siberia. The extent of near-surface permafrost has decreased substantially since 1850, with the largest area losses occurring in the last 50 years. The simulations also show that volcanic eruptions have in some cases counteracted the loss of near-surface permafrost for a few decades.
Thomas Schneider von Deimling, Hanna Lee, Thomas Ingeman-Nielsen, Sebastian Westermann, Vladimir Romanovsky, Scott Lamoureux, Donald A. Walker, Sarah Chadburn, Erin Trochim, Lei Cai, Jan Nitzbon, Stephan Jacobi, and Moritz Langer
The Cryosphere, 15, 2451–2471, https://doi.org/10.5194/tc-15-2451-2021, https://doi.org/10.5194/tc-15-2451-2021, 2021
Short summary
Short summary
Climate warming puts infrastructure built on permafrost at risk of failure. There is a growing need for appropriate model-based risk assessments. Here we present a modelling study and show an exemplary case of how a gravel road in a cold permafrost environment in Alaska might suffer from degrading permafrost under a scenario of intense climate warming. We use this case study to discuss the broader-scale applicability of our model for simulating future Arctic infrastructure failure.
Jan Nitzbon, Moritz Langer, Léo C. P. Martin, Sebastian Westermann, Thomas Schneider von Deimling, and Julia Boike
The Cryosphere, 15, 1399–1422, https://doi.org/10.5194/tc-15-1399-2021, https://doi.org/10.5194/tc-15-1399-2021, 2021
Short summary
Short summary
We used a numerical model to investigate how small-scale landscape heterogeneities affect permafrost thaw under climate-warming scenarios. Our results show that representing small-scale heterogeneities in the model can decide whether a landscape is water-logged or well-drained in the future. This in turn affects how fast permafrost thaws under warming. Our research emphasizes the importance of considering small-scale processes in model assessments of permafrost thaw under climate change.
Simone Maria Stuenzi, Julia Boike, William Cable, Ulrike Herzschuh, Stefan Kruse, Luidmila A. Pestryakova, Thomas Schneider von Deimling, Sebastian Westermann, Evgenii S. Zakharov, and Moritz Langer
Biogeosciences, 18, 343–365, https://doi.org/10.5194/bg-18-343-2021, https://doi.org/10.5194/bg-18-343-2021, 2021
Short summary
Short summary
Boreal forests in eastern Siberia are an essential component of global climate patterns. We use a physically based model and field measurements to study the interactions between forests, permanently frozen ground and the atmosphere. We find that forests exert a strong control on the thermal state of permafrost through changing snow cover dynamics and altering the surface energy balance, through absorbing most of the incoming solar radiation and suppressing below-canopy turbulent fluxes.
T. Schneider von Deimling, G. Grosse, J. Strauss, L. Schirrmeister, A. Morgenstern, S. Schaphoff, M. Meinshausen, and J. Boike
Biogeosciences, 12, 3469–3488, https://doi.org/10.5194/bg-12-3469-2015, https://doi.org/10.5194/bg-12-3469-2015, 2015
Short summary
Short summary
We have modelled the carbon release from thawing permafrost soils under various scenarios of future warming. Our results suggests that up to about 140Pg of carbon could be released under strong warming by end of the century. We have shown that abrupt thaw processes under thermokarst lakes can unlock large amounts of perennially frozen carbon stored in deep deposits (which extend many metres into the soil).
M. Eby, A. J. Weaver, K. Alexander, K. Zickfeld, A. Abe-Ouchi, A. A. Cimatoribus, E. Crespin, S. S. Drijfhout, N. R. Edwards, A. V. Eliseev, G. Feulner, T. Fichefet, C. E. Forest, H. Goosse, P. B. Holden, F. Joos, M. Kawamiya, D. Kicklighter, H. Kienert, K. Matsumoto, I. I. Mokhov, E. Monier, S. M. Olsen, J. O. P. Pedersen, M. Perrette, G. Philippon-Berthier, A. Ridgwell, A. Schlosser, T. Schneider von Deimling, G. Shaffer, R. S. Smith, R. Spahni, A. P. Sokolov, M. Steinacher, K. Tachiiri, K. Tokos, M. Yoshimori, N. Zeng, and F. Zhao
Clim. Past, 9, 1111–1140, https://doi.org/10.5194/cp-9-1111-2013, https://doi.org/10.5194/cp-9-1111-2013, 2013
Nils Weitzel, Heather Andres, Jean-Philippe Baudouin, Marie-Luise Kapsch, Uwe Mikolajewicz, Lukas Jonkers, Oliver Bothe, Elisa Ziegler, Thomas Kleinen, André Paul, and Kira Rehfeld
Clim. Past, 20, 865–890, https://doi.org/10.5194/cp-20-865-2024, https://doi.org/10.5194/cp-20-865-2024, 2024
Short summary
Short summary
The ability of climate models to faithfully reproduce past warming episodes is a valuable test considering potentially large future warming. We develop a new method to compare simulations of the last deglaciation with temperature reconstructions. We find that reconstructions differ more between regions than simulations, potentially due to deficiencies in the simulation design, models, or reconstructions. Our work is a promising step towards benchmarking simulations of past climate transitions.
Yona Silvy, Thomas L. Frölicher, Jens Terhaar, Fortunat Joos, Friedrich A. Burger, Fabrice Lacroix, Myles Allen, Raffaele Bernadello, Laurent Bopp, Victor Brovkin, Jonathan R. Buzan, Patricia Cadule, Martin Dix, John Dunne, Pierre Friedlingstein, Goran Georgievski, Tomohiro Hajima, Stuart Jenkins, Michio Kawamiya, Nancy Y. Kiang, Vladimir Lapin, Donghyun Lee, Paul Lerner, Nadine Mengis, Estela A. Monteiro, David Paynter, Glen P. Peters, Anastasia Romanou, Jörg Schwinger, Sarah Sparrow, Eric Stofferahn, Jerry Tjiputra, Etienne Tourigny, and Tilo Ziehn
EGUsphere, https://doi.org/10.5194/egusphere-2024-488, https://doi.org/10.5194/egusphere-2024-488, 2024
Short summary
Short summary
We apply the Adaptive Emission Reduction Approach with Earth System Models to provide simulations in which all ESMs converge at 1.5 °C and 2 °C warming levels. These simulations provide compatible emission pathways for a given warming level, uncovering uncertainty ranges previously missing in the CMIP scenarios. This new type of target-based emission-driven simulations offers a more coherent assessment across ESMs for studying both the carbon cycle and impacts under climate stabilization.
Colin Gareth Jones, Fanny Adloff, Ben Booth, Peter Cox, Veronika Eyring, Pierre Friedlingstein, Katja Frieler, Helene Hewitt, Hazel Jeffery, Sylvie Joussaume, Torben Koenigk, Bryan N. Lawrence, Eleanor O'Rourke, Malcolm Roberts, Benjamin 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 J. Doblas-Reyes, Markus G. Donat, Italo Epicoco, Pete Falloon, Sandro Fiore, Thomas Froelicher, Neven Fuckar, Matthew Gidden, Helge Goessling, Rune Grand Graversen, Silvio Gualdi, Jose Manuel Gutiérrez, Tatiana Ilyina, Daniela Jacob, Chris Jones, Martin Juckes, Elizabeth Kendon, Erik Kjellström, Reto Knutti, Jason A. Lowe, Matthew Mizielinski, Paola Nassisi, Michael Obersteiner, Pierre Regnier, Romain Roehrig, David Salas y Melia, Carl-Friedrich Schleussner, Michael Schulz, Enrico Scoccimarro, Laurent Terray, Hannes Thiemann, Richard Wood, Shuting Yang, and Sönke Zaehle
EGUsphere, https://doi.org/10.5194/egusphere-2024-453, https://doi.org/10.5194/egusphere-2024-453, 2024
Short summary
Short summary
We propose a number of priority areas for the international climate research community to address over the coming ~6 years (i.e. to 2030). Advances in these areas will increase our understanding of past and future Earth system change, including the societal and environmental impacts of this change, as well as deliver significantly improved scientific support to international climate policy, such as the 7th IPCC Assessment Report and the UNFCCC Global Stocktake under the Paris Climate Agreement.
Tomohiro Hajima, Michio Kawamiya, Akihiko Ito, Kaoru Tachiiri, Chris Jones, Vivek Arora, Victor Brovkin, Roland Séférian, Spencer Liddicoat, Pierre Friedlingstein, and Elena Shevliakova
EGUsphere, https://doi.org/10.5194/egusphere-2024-188, https://doi.org/10.5194/egusphere-2024-188, 2024
Short summary
Short summary
This study analyzes atmospheric CO2 concentrations and global carbon budgets simulated by multiple Earth system models, using several types of simulations. We successfully identified problems of global carbon budget in each model. We also found urgent issues that should be solved in the latest generation of models, land use change CO2 emissions.
Moritz Langer, Jan Nitzbon, Brian Groenke, Lisa-Marie Assmann, Thomas Schneider von Deimling, Simone Maria Stuenzi, and Sebastian Westermann
The Cryosphere, 18, 363–385, https://doi.org/10.5194/tc-18-363-2024, https://doi.org/10.5194/tc-18-363-2024, 2024
Short summary
Short summary
Using a model that can simulate the evolution of Arctic permafrost over centuries to millennia, we find that post-industrialization permafrost warming has three "hotspots" in NE Canada, N Alaska, and W Siberia. The extent of near-surface permafrost has decreased substantially since 1850, with the largest area losses occurring in the last 50 years. The simulations also show that volcanic eruptions have in some cases counteracted the loss of near-surface permafrost for a few decades.
Nico Wunderling, Anna S. von der Heydt, Yevgeny Aksenov, Stephen Barker, Robbin Bastiaansen, Victor Brovkin, Maura Brunetti, Victor Couplet, Thomas Kleinen, Caroline H. Lear, Johannes Lohmann, Rosa Maria Roman-Cuesta, Sacha Sinet, Didier Swingedouw, Ricarda Winkelmann, Pallavi Anand, Jonathan Barichivich, Sebastian Bathiany, Mara Baudena, John T. Bruun, Cristiano M. Chiessi, Helen K. Coxall, David Docquier, Jonathan F. Donges, Swinda K. J. Falkena, Ann Kristin Klose, David Obura, Juan Rocha, Stefanie Rynders, Norman Julius Steinert, and Matteo Willeit
Earth Syst. Dynam., 15, 41–74, https://doi.org/10.5194/esd-15-41-2024, https://doi.org/10.5194/esd-15-41-2024, 2024
Short summary
Short summary
This paper maps out the state-of-the-art literature on interactions between tipping elements relevant for current global warming pathways. We find indications that many of the interactions between tipping elements are destabilizing. This means that tipping cascades cannot be ruled out on centennial to millennial timescales at global warming levels between 1.5 and 2.0 °C or on shorter timescales if global warming surpasses 2.0 °C.
Nora Farina Specht, Martin Claussen, and Thomas Kleinen
EGUsphere, https://doi.org/10.5194/egusphere-2023-3081, https://doi.org/10.5194/egusphere-2023-3081, 2024
Short summary
Short summary
The terrestrial water cycle over the Sahara/Sahel is closed by implementing a new model of endorheic lakes into a climate model. A factor analysis of mid-Holocene simulations shows that dynamic lakes and dynamic vegetation individually cause a precipitation increase over northern Africa that is, in the sum, larger than the precipitation increase caused by interacting lakes and vegetation dynamics. Thus, the lake-vegetation interaction causes a relative drying response over the entire Sahel.
Tuula Aalto, Aki Tsuruta, Jarmo Mäkelä, Jurek Mueller, Maria Tenkanen, Eleanor Burke, Sarah Chadburn, Yao Gao, Vilma Mannisenaho, Thomas Kleinen, Hanna Lee, Antti Leppänen, Tiina Markkanen, Stefano Materia, Paul Miller, Daniele Peano, Olli Peltola, Benjamin Poulter, Maarit Raivonen, Marielle Saunois, David Wårlind, and Sönke Zaehle
EGUsphere, https://doi.org/10.5194/egusphere-2023-2873, https://doi.org/10.5194/egusphere-2023-2873, 2024
Short summary
Short summary
Wetland methane responses to temperature and precipitation were studied in a boreal wetland-rich region in Northern Europe using ecosystem models, atmospheric inversions and up-scaled flux observations. The ecosystem models differed in their responses to temperature and precipitation and in their seasonality. However, multi-model means, inversions and up-scaled fluxes had similar seasonality, and they suggested co-limitation by temperature and precipitation.
Katharina Jentzsch, Elisa Männistö, Maija E. Marushchak, Aino Korrensalo, Lona van Delden, Eeva-Stiina Tuittila, Christian Knoblauch, and Claire C. Treat
EGUsphere, https://doi.org/10.5194/egusphere-2023-3098, https://doi.org/10.5194/egusphere-2023-3098, 2024
Short summary
Short summary
Peatlands store large amounts of carbon which may increasingly be released as greenhouse gases under a warming climate. We research how environmental conditions affect the methane release from a boreal peatland. Vegetation had a strong impact year-round – methane release was reduced by some plant species but increased by others. The total vegetation currently lowers the methane release to the atmosphere. However, this balance can turn around as climate change alters the vegetation composition.
Daniela Guasconi, Sara Cousins, Stefano Manzoni, Nina Roth, and Gustaf Hugelius
EGUsphere, https://doi.org/10.5194/egusphere-2023-2673, https://doi.org/10.5194/egusphere-2023-2673, 2023
Short summary
Short summary
This study assesses the effects of experimental drought and of a soil amendment on soil and vegetation carbon pools, at different soil depths. Drought consistently reduced soil moisture and aboveground biomass, while compost increased total soil carbon content and aboveground biomass, and effects were more pronounced in the topsoil. Root biomass was not significantly affected by the treatments. The contrasting response of roots and shoots improves our understanding of ecosystem carbon dynamics.
Yi Xi, Chunjing Qiu, Yuan Zhang, Dan Zhu, Shushi Peng, Gustaf Hugelius, Jinfeng Chang, Elodie Salmon, and Philippe Ciais
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-207, https://doi.org/10.5194/gmd-2023-207, 2023
Revised manuscript under review for GMD
Short summary
Short summary
The ORCHIDEE-MICT (ORganizing Carbon and Hydrology in Dynamic EcosystEms–aMeliorated Interactions between Carbon and Temperature) model can simulate carbon cycle and hydrology at subgrid scale but energy budgets only at grid scale. This paper assessed the implementation of a multi-tiling energy budget approach in ORCHIDEE-MICT and found that warmer surface and soil temperatures, wetter soil moisture, and more soil organic carbon across the Northern Hemisphere compared to the original version.
Annett Bartsch, Aleksandra Efimova, Barbara Widhalm, Xaver Muri, Clemens von Baeckmann, Helena Bergstedt, Ksenia Ermokhina, Gustaf Hugelius, Birgit Heim, and Marina Leibmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2295, https://doi.org/10.5194/egusphere-2023-2295, 2023
Short summary
Short summary
Wetness gradients and landcover diversity for the entire Arctic tundra have been assessed using a novel satellite data based map. Patterns of lakes, wetlands, general soil moisture conditions and vegetation physiognomy are represented at 10 m. About 40 % of the area north of the treeline falls into three units of dry types with limited shrub growth. Wetter regions have higher landcover diversity than drier regions.
István Dunkl, Nicole Lovenduski, Alessio Collalti, Vivek K. Arora, Tatiana Ilyina, and Victor Brovkin
Biogeosciences, 20, 3523–3538, https://doi.org/10.5194/bg-20-3523-2023, https://doi.org/10.5194/bg-20-3523-2023, 2023
Short summary
Short summary
Despite differences in the reproduction of gross primary productivity (GPP) by Earth system models (ESMs), ESMs have similar predictability of the global carbon cycle. We found that, although GPP variability originates from different regions and is driven by different climatic variables across the ESMs, the ESMs rely on the same mechanisms to predict their own GPP. This shows that the predictability of the carbon cycle is limited by our understanding of variability rather than predictability.
Lukas Rimondini, Thomas Gumbricht, Anders Ahlström, and Gustaf Hugelius
Earth Syst. Sci. Data, 15, 3473–3482, https://doi.org/10.5194/essd-15-3473-2023, https://doi.org/10.5194/essd-15-3473-2023, 2023
Short summary
Short summary
Peatlands have historically sequestrated large amounts of carbon and contributed to atmospheric cooling. However, human activities and climate change may instead turn them into considerable carbon emitters. In this study, we produced high-quality maps showing the extent of peatlands in the forests of Sweden, one of the most peatland-dense countries in the world. The maps are publicly available and may be used to support work promoting sustainable peatland management and combat their degradation.
Zoé Rehder, Thomas Kleinen, Lars Kutzbach, Victor Stepanenko, Moritz Langer, and Victor Brovkin
Biogeosciences, 20, 2837–2855, https://doi.org/10.5194/bg-20-2837-2023, https://doi.org/10.5194/bg-20-2837-2023, 2023
Short summary
Short summary
We use a new model to investigate how methane emissions from Arctic ponds change with warming. We find that emissions increase substantially. Under annual temperatures 5 °C above present temperatures, pond methane emissions are more than 3 times higher than now. Most of this increase is caused by an increase in plant productivity as plants provide the substrate microbes used to produce methane. We conclude that vegetation changes need to be included in predictions of pond methane emissions.
Nathaelle Bouttes, Lester Kwiatkowski, Manon Berger, Victor Brovkin, and Guy Munhoven
EGUsphere, https://doi.org/10.5194/egusphere-2023-1162, https://doi.org/10.5194/egusphere-2023-1162, 2023
Short summary
Short summary
Coral reefs are crucial for biodiversity, but they also play a role in the carbon cycle on long time scales of a few thousand years. To better simulate the future and past evolution of coral reefs and their effect on the global carbon cycle, hence on atmospheric CO2 concentration, it is necessary to include coral reefs within a climate model. Here we describe the inclusion of coral reef carbonate production in a carbon-climate model and its validation in comparison to existing modern data.
Matteo Willeit, Tatiana Ilyina, Bo Liu, Christoph Heinze, Mahé Perrette, Malte Heinemann, Daniela Dalmonech, Victor Brovkin, Guy Munhoven, Janine Börker, Jens Hartmann, Gibran Romero-Mujalli, and Andrey Ganopolski
Geosci. Model Dev., 16, 3501–3534, https://doi.org/10.5194/gmd-16-3501-2023, https://doi.org/10.5194/gmd-16-3501-2023, 2023
Short summary
Short summary
In this paper we present the carbon cycle component of the newly developed fast Earth system model CLIMBER-X. The model can be run with interactive atmospheric CO2 to investigate the feedbacks between climate and the carbon cycle on temporal scales ranging from decades to > 100 000 years. CLIMBER-X is expected to be a useful tool for studying past climate–carbon cycle changes and for the investigation of the long-term future evolution of the Earth system.
Thomas Kleinen, Sergey Gromov, Benedikt Steil, and Victor Brovkin
Clim. Past, 19, 1081–1099, https://doi.org/10.5194/cp-19-1081-2023, https://doi.org/10.5194/cp-19-1081-2023, 2023
Short summary
Short summary
We modelled atmospheric methane continuously from the last glacial maximum to the present using a state-of-the-art Earth system model. Our model results compare well with reconstructions from ice cores and improve our understanding of a very intriguing period of Earth system history, the deglaciation, when atmospheric methane changed quickly and strongly. Deglacial methane changes are driven by emissions from tropical wetlands, with wetlands in high northern latitudes being secondary.
Philipp de Vrese, Goran Georgievski, Jesus Fidel Gonzalez Rouco, Dirk Notz, Tobias Stacke, Norman Julius Steinert, Stiig Wilkenskjeld, and Victor Brovkin
The Cryosphere, 17, 2095–2118, https://doi.org/10.5194/tc-17-2095-2023, https://doi.org/10.5194/tc-17-2095-2023, 2023
Short summary
Short summary
The current generation of Earth system models exhibits large inter-model differences in the simulated climate of the Arctic and subarctic zone. We used an adapted version of the Max Planck Institute (MPI) Earth System Model to show that differences in the representation of the soil hydrology in permafrost-affected regions could help explain a large part of this inter-model spread and have pronounced impacts on important elements of Earth systems as far to the south as the tropics.
Peter Stimmler, Mathias Goeckede, Bo Elberling, Susan Natali, Peter Kuhry, Nia Perron, Fabrice Lacroix, Gustaf Hugelius, Oliver Sonnentag, Jens Strauss, Christina Minions, Michael Sommer, and Jörg Schaller
Earth Syst. Sci. Data, 15, 1059–1075, https://doi.org/10.5194/essd-15-1059-2023, https://doi.org/10.5194/essd-15-1059-2023, 2023
Short summary
Short summary
Arctic soils store large amounts of carbon and nutrients. The availability of nutrients, such as silicon, calcium, iron, aluminum, phosphorus, and amorphous silica, is crucial to understand future carbon fluxes in the Arctic. Here, we provide, for the first time, a unique dataset of the availability of the abovementioned nutrients for the different soil layers, including the currently frozen permafrost layer. We relate these data to several geographical and geological parameters.
Niek Jesse Speetjens, Gustaf Hugelius, Thomas Gumbricht, Hugues Lantuit, Wouter R. Berghuijs, Philip A. Pika, Amanda Poste, and Jorien E. Vonk
Earth Syst. Sci. Data, 15, 541–554, https://doi.org/10.5194/essd-15-541-2023, https://doi.org/10.5194/essd-15-541-2023, 2023
Short summary
Short summary
The Arctic is rapidly changing. Outside the Arctic, large databases changed how researchers look at river systems and land-to-ocean processes. We present the first integrated pan-ARctic CAtchments summary DatabasE (ARCADE) (> 40 000 river catchments draining into the Arctic Ocean). It incorporates information about the drainage area with 103 geospatial, environmental, climatic, and physiographic properties and covers small watersheds , which are especially subject to change, at a high resolution
Juri Palmtag, Jaroslav Obu, Peter Kuhry, Andreas Richter, Matthias B. Siewert, Niels Weiss, Sebastian Westermann, and Gustaf Hugelius
Earth Syst. Sci. Data, 14, 4095–4110, https://doi.org/10.5194/essd-14-4095-2022, https://doi.org/10.5194/essd-14-4095-2022, 2022
Short summary
Short summary
The northern permafrost region covers 22 % of the Northern Hemisphere and holds almost twice as much carbon as the atmosphere. This paper presents data from 651 soil pedons encompassing more than 6500 samples from 16 different study areas across the northern permafrost region. We use this dataset together with ESA's global land cover dataset to estimate soil organic carbon and total nitrogen storage up to 300 cm soil depth, with estimated values of 813 Pg for carbon and 55 Pg for nitrogen.
Mateo Duque-Villegas, Martin Claussen, Victor Brovkin, and Thomas Kleinen
Clim. Past, 18, 1897–1914, https://doi.org/10.5194/cp-18-1897-2022, https://doi.org/10.5194/cp-18-1897-2022, 2022
Short summary
Short summary
Using an Earth system model of intermediate complexity, we quantify contributions of the Earth's orbit, greenhouse gases (GHGs) and ice sheets to the strength of Saharan greening during late Quaternary African humid periods (AHPs). Orbital forcing is found as the dominant factor, having a critical threshold and accounting for most of the changes in the vegetation response. However, results suggest that GHGs may influence the orbital threshold and thus may play a pivotal role for future AHPs.
Niek Jesse Speetjens, George Tanski, Victoria Martin, Julia Wagner, Andreas Richter, Gustaf Hugelius, Chris Boucher, Rachele Lodi, Christian Knoblauch, Boris P. Koch, Urban Wünsch, Hugues Lantuit, and Jorien E. Vonk
Biogeosciences, 19, 3073–3097, https://doi.org/10.5194/bg-19-3073-2022, https://doi.org/10.5194/bg-19-3073-2022, 2022
Short summary
Short summary
Climate change and warming in the Arctic exceed global averages. As a result, permanently frozen soils (permafrost) which store vast quantities of carbon in the form of dead plant material (organic matter) are thawing. Our study shows that as permafrost landscapes degrade, high concentrations of organic matter are released. Partly, this organic matter is degraded rapidly upon release, while another significant fraction enters stream networks and enters the Arctic Ocean.
Nora Farina Specht, Martin Claussen, and Thomas Kleinen
Clim. Past, 18, 1035–1046, https://doi.org/10.5194/cp-18-1035-2022, https://doi.org/10.5194/cp-18-1035-2022, 2022
Short summary
Short summary
Palaeoenvironmental records only provide a fragmentary picture of the lake and wetland extent in North Africa during the mid-Holocene. Therefore, we investigate the possible range of mid-Holocene precipitation changes caused by an estimated small and maximum lake extent and a maximum wetland extent. Results show a particularly strong monsoon precipitation response to lakes and wetlands over the Western Sahara and an increased monsoon precipitation when replacing lakes with vegetated wetlands.
Stiig Wilkenskjeld, Frederieke Miesner, Paul P. Overduin, Matteo Puglini, and Victor Brovkin
The Cryosphere, 16, 1057–1069, https://doi.org/10.5194/tc-16-1057-2022, https://doi.org/10.5194/tc-16-1057-2022, 2022
Short summary
Short summary
Thawing permafrost releases carbon to the atmosphere, enhancing global warming. Part of the permafrost soils have been flooded by rising sea levels since the last ice age, becoming subsea permafrost (SSPF). The SSPF is less studied than the part on land. In this study we use a global model to obtain rates of thawing of SSPF under different future climate scenarios until the year 3000. After the year 2100 the scenarios strongly diverge, closely connected to the eventual disappearance of sea ice.
H. E. Markus Meier, Madline Kniebusch, Christian Dieterich, Matthias Gröger, Eduardo Zorita, Ragnar Elmgren, Kai Myrberg, Markus P. Ahola, Alena Bartosova, Erik Bonsdorff, Florian Börgel, Rene Capell, Ida Carlén, Thomas Carlund, Jacob Carstensen, Ole B. Christensen, Volker Dierschke, Claudia Frauen, Morten Frederiksen, Elie Gaget, Anders Galatius, Jari J. Haapala, Antti Halkka, Gustaf Hugelius, Birgit Hünicke, Jaak Jaagus, Mart Jüssi, Jukka Käyhkö, Nina Kirchner, Erik Kjellström, Karol Kulinski, Andreas Lehmann, Göran Lindström, Wilhelm May, Paul A. Miller, Volker Mohrholz, Bärbel Müller-Karulis, Diego Pavón-Jordán, Markus Quante, Marcus Reckermann, Anna Rutgersson, Oleg P. Savchuk, Martin Stendel, Laura Tuomi, Markku Viitasalo, Ralf Weisse, and Wenyan Zhang
Earth Syst. Dynam., 13, 457–593, https://doi.org/10.5194/esd-13-457-2022, https://doi.org/10.5194/esd-13-457-2022, 2022
Short summary
Short summary
Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge about the effects of global warming on past and future changes in the climate of the Baltic Sea region is summarised and assessed. The study is an update of the Second Assessment of Climate Change (BACC II) published in 2015 and focuses on the atmosphere, land, cryosphere, ocean, sediments, and the terrestrial and marine biosphere.
Philippe Ciais, Ana Bastos, Frédéric Chevallier, Ronny Lauerwald, Ben Poulter, Josep G. Canadell, Gustaf Hugelius, Robert B. Jackson, Atul Jain, Matthew Jones, Masayuki Kondo, Ingrid T. Luijkx, Prabir K. Patra, Wouter Peters, Julia Pongratz, Ana Maria Roxana Petrescu, Shilong Piao, Chunjing Qiu, Celso Von Randow, Pierre Regnier, Marielle Saunois, Robert Scholes, Anatoly Shvidenko, Hanqin Tian, Hui Yang, Xuhui Wang, and Bo Zheng
Geosci. Model Dev., 15, 1289–1316, https://doi.org/10.5194/gmd-15-1289-2022, https://doi.org/10.5194/gmd-15-1289-2022, 2022
Short summary
Short summary
The second phase of the Regional Carbon Cycle Assessment and Processes (RECCAP) will provide updated quantification and process understanding of CO2, CH4, and N2O emissions and sinks for ten regions of the globe. In this paper, we give definitions, review different methods, and make recommendations for estimating different components of the total land–atmosphere carbon exchange for each region in a consistent and complete approach.
István Dunkl, Aaron Spring, Pierre Friedlingstein, and Victor Brovkin
Earth Syst. Dynam., 12, 1413–1426, https://doi.org/10.5194/esd-12-1413-2021, https://doi.org/10.5194/esd-12-1413-2021, 2021
Short summary
Short summary
The variability in atmospheric CO2 is largely controlled by terrestrial carbon fluxes. These land–atmosphere fluxes are predictable for around 2 years, but the mechanisms providing the predictability are not well understood. By decomposing the predictability of carbon fluxes into individual contributors we were able to explain the spatial and seasonal patterns and the interannual variability of CO2 flux predictability.
Aaron Spring, István Dunkl, Hongmei Li, Victor Brovkin, and Tatiana Ilyina
Earth Syst. Dynam., 12, 1139–1167, https://doi.org/10.5194/esd-12-1139-2021, https://doi.org/10.5194/esd-12-1139-2021, 2021
Short summary
Short summary
Numerical carbon cycle prediction models usually do not start from observed carbon states due to sparse observations. Instead, only physical climate is reconstructed, assuming that the carbon cycle follows indirectly. Here, we test in an idealized framework how well this indirect and direct reconstruction with perfect observations works. We find that indirect reconstruction works quite well and that improvements from the direct method are limited, strengthening the current indirect use.
David Olefeldt, Mikael Hovemyr, McKenzie A. Kuhn, David Bastviken, Theodore J. Bohn, John Connolly, Patrick Crill, Eugénie S. Euskirchen, Sarah A. Finkelstein, Hélène Genet, Guido Grosse, Lorna I. Harris, Liam Heffernan, Manuel Helbig, Gustaf Hugelius, Ryan Hutchins, Sari Juutinen, Mark J. Lara, Avni Malhotra, Kristen Manies, A. David McGuire, Susan M. Natali, Jonathan A. O'Donnell, Frans-Jan W. Parmentier, Aleksi Räsänen, Christina Schädel, Oliver Sonnentag, Maria Strack, Suzanne E. Tank, Claire Treat, Ruth K. Varner, Tarmo Virtanen, Rebecca K. Warren, and Jennifer D. Watts
Earth Syst. Sci. Data, 13, 5127–5149, https://doi.org/10.5194/essd-13-5127-2021, https://doi.org/10.5194/essd-13-5127-2021, 2021
Short summary
Short summary
Wetlands, lakes, and rivers are important sources of the greenhouse gas methane to the atmosphere. To understand current and future methane emissions from northern regions, we need maps that show the extent and distribution of specific types of wetlands, lakes, and rivers. The Boreal–Arctic Wetland and Lake Dataset (BAWLD) provides maps of five wetland types, seven lake types, and three river types for northern regions and will improve our ability to predict future methane emissions.
Alexander J. Winkler, Ranga B. Myneni, Alexis Hannart, Stephen Sitch, Vanessa Haverd, Danica Lombardozzi, Vivek K. Arora, Julia Pongratz, Julia E. M. S. Nabel, Daniel S. Goll, Etsushi Kato, Hanqin Tian, Almut Arneth, Pierre Friedlingstein, Atul K. Jain, Sönke Zaehle, and Victor Brovkin
Biogeosciences, 18, 4985–5010, https://doi.org/10.5194/bg-18-4985-2021, https://doi.org/10.5194/bg-18-4985-2021, 2021
Short summary
Short summary
Satellite observations since the early 1980s show that Earth's greening trend is slowing down and that browning clusters have been emerging, especially in the last 2 decades. A collection of model simulations in conjunction with causal theory points at climatic changes as a key driver of vegetation changes in natural ecosystems. Most models underestimate the observed vegetation browning, especially in tropical rainforests, which could be due to an excessive CO2 fertilization effect in models.
Thomas Schneider von Deimling, Hanna Lee, Thomas Ingeman-Nielsen, Sebastian Westermann, Vladimir Romanovsky, Scott Lamoureux, Donald A. Walker, Sarah Chadburn, Erin Trochim, Lei Cai, Jan Nitzbon, Stephan Jacobi, and Moritz Langer
The Cryosphere, 15, 2451–2471, https://doi.org/10.5194/tc-15-2451-2021, https://doi.org/10.5194/tc-15-2451-2021, 2021
Short summary
Short summary
Climate warming puts infrastructure built on permafrost at risk of failure. There is a growing need for appropriate model-based risk assessments. Here we present a modelling study and show an exemplary case of how a gravel road in a cold permafrost environment in Alaska might suffer from degrading permafrost under a scenario of intense climate warming. We use this case study to discuss the broader-scale applicability of our model for simulating future Arctic infrastructure failure.
Zhen Zhang, Etienne Fluet-Chouinard, Katherine Jensen, Kyle McDonald, Gustaf Hugelius, Thomas Gumbricht, Mark Carroll, Catherine Prigent, Annett Bartsch, and Benjamin Poulter
Earth Syst. Sci. Data, 13, 2001–2023, https://doi.org/10.5194/essd-13-2001-2021, https://doi.org/10.5194/essd-13-2001-2021, 2021
Short summary
Short summary
The spatiotemporal distribution of wetlands is one of the important and yet uncertain factors determining the time and locations of methane fluxes. The Wetland Area and Dynamics for Methane Modeling (WAD2M) dataset describes the global data product used to quantify the areal dynamics of natural wetlands and how global wetlands are changing in response to climate.
Jan Nitzbon, Moritz Langer, Léo C. P. Martin, Sebastian Westermann, Thomas Schneider von Deimling, and Julia Boike
The Cryosphere, 15, 1399–1422, https://doi.org/10.5194/tc-15-1399-2021, https://doi.org/10.5194/tc-15-1399-2021, 2021
Short summary
Short summary
We used a numerical model to investigate how small-scale landscape heterogeneities affect permafrost thaw under climate-warming scenarios. Our results show that representing small-scale heterogeneities in the model can decide whether a landscape is water-logged or well-drained in the future. This in turn affects how fast permafrost thaws under warming. Our research emphasizes the importance of considering small-scale processes in model assessments of permafrost thaw under climate change.
Philipp de Vrese, Tobias Stacke, Thomas Kleinen, and Victor Brovkin
The Cryosphere, 15, 1097–1130, https://doi.org/10.5194/tc-15-1097-2021, https://doi.org/10.5194/tc-15-1097-2021, 2021
Short summary
Short summary
With large amounts of carbon stored in frozen soils and a highly energy-limited vegetation the Arctic is very sensitive to changes in climate. Here our simulations with the land surface model JSBACH reveal a number of offsetting factors moderating the Arctic's net response to global warming. More importantly we find that the effects of climate change may not be fully reversible on decadal timescales, leading to substantially different CH4 emissions depending on whether the Arctic warms or cools.
Claudia Tebaldi, Kevin Debeire, Veronika Eyring, Erich Fischer, John Fyfe, Pierre Friedlingstein, Reto Knutti, Jason Lowe, Brian O'Neill, Benjamin Sanderson, Detlef van Vuuren, Keywan Riahi, Malte Meinshausen, Zebedee Nicholls, Katarzyna B. Tokarska, George Hurtt, Elmar Kriegler, Jean-Francois Lamarque, Gerald Meehl, Richard Moss, Susanne E. Bauer, Olivier Boucher, Victor Brovkin, Young-Hwa Byun, Martin Dix, Silvio Gualdi, Huan Guo, Jasmin G. John, Slava Kharin, YoungHo Kim, Tsuyoshi Koshiro, Libin Ma, Dirk Olivié, Swapna Panickal, Fangli Qiao, Xinyao Rong, Nan Rosenbloom, Martin Schupfner, Roland Séférian, Alistair Sellar, Tido Semmler, Xiaoying Shi, Zhenya Song, Christian Steger, Ronald Stouffer, Neil Swart, Kaoru Tachiiri, Qi Tang, Hiroaki Tatebe, Aurore Voldoire, Evgeny Volodin, Klaus Wyser, Xiaoge Xin, Shuting Yang, Yongqiang Yu, and Tilo Ziehn
Earth Syst. Dynam., 12, 253–293, https://doi.org/10.5194/esd-12-253-2021, https://doi.org/10.5194/esd-12-253-2021, 2021
Short summary
Short summary
We present an overview of CMIP6 ScenarioMIP outcomes from up to 38 participating ESMs according to the new SSP-based scenarios. Average temperature and precipitation projections according to a wide range of forcings, spanning a wider range than the CMIP5 projections, are documented as global averages and geographic patterns. Times of crossing various warming levels are computed, together with benefits of mitigation for selected pairs of scenarios. Comparisons with CMIP5 are also discussed.
Simone Maria Stuenzi, Julia Boike, William Cable, Ulrike Herzschuh, Stefan Kruse, Luidmila A. Pestryakova, Thomas Schneider von Deimling, Sebastian Westermann, Evgenii S. Zakharov, and Moritz Langer
Biogeosciences, 18, 343–365, https://doi.org/10.5194/bg-18-343-2021, https://doi.org/10.5194/bg-18-343-2021, 2021
Short summary
Short summary
Boreal forests in eastern Siberia are an essential component of global climate patterns. We use a physically based model and field measurements to study the interactions between forests, permanently frozen ground and the atmosphere. We find that forests exert a strong control on the thermal state of permafrost through changing snow cover dynamics and altering the surface energy balance, through absorbing most of the incoming solar radiation and suppressing below-canopy turbulent fluxes.
Lena R. Boysen, Victor Brovkin, Julia Pongratz, David M. Lawrence, Peter Lawrence, Nicolas Vuichard, Philippe Peylin, Spencer Liddicoat, Tomohiro Hajima, Yanwu Zhang, Matthias Rocher, Christine Delire, Roland Séférian, Vivek K. Arora, Lars Nieradzik, Peter Anthoni, Wim Thiery, Marysa M. Laguë, Deborah Lawrence, and Min-Hui Lo
Biogeosciences, 17, 5615–5638, https://doi.org/10.5194/bg-17-5615-2020, https://doi.org/10.5194/bg-17-5615-2020, 2020
Short summary
Short summary
We find a biogeophysically induced global cooling with strong carbon losses in a 20 million square kilometre idealized deforestation experiment performed by nine CMIP6 Earth system models. It takes many decades for the temperature signal to emerge, with non-local effects playing an important role. Despite a consistent experimental setup, models diverge substantially in their climate responses. This study offers unprecedented insights for understanding land use change effects in CMIP6 models.
Taraka Davies-Barnard, Johannes Meyerholt, Sönke Zaehle, Pierre Friedlingstein, Victor Brovkin, Yuanchao Fan, Rosie A. Fisher, Chris D. Jones, Hanna Lee, Daniele Peano, Benjamin Smith, David Wårlind, and Andy J. Wiltshire
Biogeosciences, 17, 5129–5148, https://doi.org/10.5194/bg-17-5129-2020, https://doi.org/10.5194/bg-17-5129-2020, 2020
Vivek K. Arora, Anna Katavouta, Richard G. Williams, Chris D. Jones, Victor Brovkin, Pierre Friedlingstein, Jörg Schwinger, Laurent Bopp, Olivier Boucher, Patricia Cadule, Matthew A. Chamberlain, James R. Christian, Christine Delire, Rosie A. Fisher, Tomohiro Hajima, Tatiana Ilyina, Emilie Joetzjer, Michio Kawamiya, Charles D. Koven, John P. Krasting, Rachel M. Law, David M. Lawrence, Andrew Lenton, Keith Lindsay, Julia Pongratz, Thomas Raddatz, Roland Séférian, Kaoru Tachiiri, Jerry F. Tjiputra, Andy Wiltshire, Tongwen Wu, and Tilo Ziehn
Biogeosciences, 17, 4173–4222, https://doi.org/10.5194/bg-17-4173-2020, https://doi.org/10.5194/bg-17-4173-2020, 2020
Short summary
Short summary
Since the preindustrial period, land and ocean have taken up about half of the carbon emitted into the atmosphere by humans. Comparison of different earth system models with the carbon cycle allows us to assess how carbon uptake by land and ocean differs among models. This yields an estimate of uncertainty in our understanding of how land and ocean respond to increasing atmospheric CO2. This paper summarizes results from two such model intercomparison projects that use an idealized scenario.
Marielle Saunois, Ann R. Stavert, Ben Poulter, Philippe Bousquet, Josep G. Canadell, Robert B. Jackson, Peter A. Raymond, Edward J. Dlugokencky, Sander Houweling, Prabir K. Patra, Philippe Ciais, Vivek K. Arora, David Bastviken, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Kimberly M. Carlson, Mark Carrol, Simona Castaldi, Naveen Chandra, Cyril Crevoisier, Patrick M. Crill, Kristofer Covey, Charles L. Curry, Giuseppe Etiope, Christian Frankenberg, Nicola Gedney, Michaela I. Hegglin, Lena Höglund-Isaksson, Gustaf Hugelius, Misa Ishizawa, Akihiko Ito, Greet Janssens-Maenhout, Katherine M. Jensen, Fortunat Joos, Thomas Kleinen, Paul B. Krummel, Ray L. Langenfelds, Goulven G. Laruelle, Licheng Liu, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Joe McNorton, Paul A. Miller, Joe R. Melton, Isamu Morino, Jurek Müller, Fabiola Murguia-Flores, Vaishali Naik, Yosuke Niwa, Sergio Noce, Simon O'Doherty, Robert J. Parker, Changhui Peng, Shushi Peng, Glen P. Peters, Catherine Prigent, Ronald Prinn, Michel Ramonet, Pierre Regnier, William J. Riley, Judith A. Rosentreter, Arjo Segers, Isobel J. Simpson, Hao Shi, Steven J. Smith, L. Paul Steele, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Francesco N. Tubiello, Aki Tsuruta, Nicolas Viovy, Apostolos Voulgarakis, Thomas S. Weber, Michiel van Weele, Guido R. van der Werf, Ray F. Weiss, Doug Worthy, Debra Wunch, Yi Yin, Yukio Yoshida, Wenxin Zhang, Zhen Zhang, Yuanhong Zhao, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 12, 1561–1623, https://doi.org/10.5194/essd-12-1561-2020, https://doi.org/10.5194/essd-12-1561-2020, 2020
Short summary
Short summary
Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. We have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. This is the second version of the review dedicated to the decadal methane budget, integrating results of top-down and bottom-up estimates.
Matteo Puglini, Victor Brovkin, Pierre Regnier, and Sandra Arndt
Biogeosciences, 17, 3247–3275, https://doi.org/10.5194/bg-17-3247-2020, https://doi.org/10.5194/bg-17-3247-2020, 2020
Short summary
Short summary
A reaction-transport model to assess the potential non-turbulent methane flux from the East Siberian Arctic sediments to water columns is applied here. We show that anaerobic oxidation of methane (AOM) is an efficient filter except for high values of sedimentation rate and advective flow, which enable considerable non-turbulent steady-state methane fluxes. Significant transient methane fluxes can also occur during the building-up phase of the AOM-performing biomass microbial community.
Andrew H. MacDougall, Thomas L. Frölicher, Chris D. Jones, Joeri Rogelj, H. Damon Matthews, Kirsten Zickfeld, Vivek K. Arora, Noah J. Barrett, Victor Brovkin, Friedrich A. Burger, Micheal Eby, Alexey V. Eliseev, Tomohiro Hajima, Philip B. Holden, Aurich Jeltsch-Thömmes, Charles Koven, Nadine Mengis, Laurie Menviel, Martine Michou, Igor I. Mokhov, Akira Oka, Jörg Schwinger, Roland Séférian, Gary Shaffer, Andrei Sokolov, Kaoru Tachiiri, Jerry Tjiputra, Andrew Wiltshire, and Tilo Ziehn
Biogeosciences, 17, 2987–3016, https://doi.org/10.5194/bg-17-2987-2020, https://doi.org/10.5194/bg-17-2987-2020, 2020
Short summary
Short summary
The Zero Emissions Commitment (ZEC) is the change in global temperature expected to occur following the complete cessation of CO2 emissions. Here we use 18 climate models to assess the value of ZEC. For our experiment we find that ZEC 50 years after emissions cease is between −0.36 to +0.29 °C. The most likely value of ZEC is assessed to be close to zero. However, substantial continued warming for decades or centuries following cessation of CO2 emission cannot be ruled out.
Thomas Kleinen, Uwe Mikolajewicz, and Victor Brovkin
Clim. Past, 16, 575–595, https://doi.org/10.5194/cp-16-575-2020, https://doi.org/10.5194/cp-16-575-2020, 2020
Short summary
Short summary
We investigate the changes in natural methane emissions between the Last Glacial Maximum and preindustrial periods with a methane-enabled version of MPI-ESM. We consider all natural sources of methane except for emissions from wild animals and geological sources. Changes are dominated by changes in tropical wetland emissions, high-latitude wetlands play a secondary role, and all other natural sources are of minor importance. We explain the changes in ice core methane by methane emissions only.
Peter Kuhry, Jiří Bárta, Daan Blok, Bo Elberling, Samuel Faucherre, Gustaf Hugelius, Christian J. Jørgensen, Andreas Richter, Hana Šantrůčková, and Niels Weiss
Biogeosciences, 17, 361–379, https://doi.org/10.5194/bg-17-361-2020, https://doi.org/10.5194/bg-17-361-2020, 2020
Georgii A. Alexandrov, Victor A. Brovkin, Thomas Kleinen, and Zicheng Yu
Biogeosciences, 17, 47–54, https://doi.org/10.5194/bg-17-47-2020, https://doi.org/10.5194/bg-17-47-2020, 2020
Alexander J. Winkler, Ranga B. Myneni, and Victor Brovkin
Earth Syst. Dynam., 10, 501–523, https://doi.org/10.5194/esd-10-501-2019, https://doi.org/10.5194/esd-10-501-2019, 2019
Short summary
Short summary
The concept of
emergent constraintsis a key method to reduce uncertainty in multi-model climate projections using historical simulations and observations. Here, we present an in-depth analysis of the applicability of the method and uncover possible limitations. Key limitations are a lack of comparability (temporal, spatial, and conceptual) between models and observations and the disagreement between models on system dynamics throughout different levels of atmospheric CO2 concentration.
Victor Brovkin, Stephan Lorenz, Thomas Raddatz, Tatiana Ilyina, Irene Stemmler, Matthew Toohey, and Martin Claussen
Biogeosciences, 16, 2543–2555, https://doi.org/10.5194/bg-16-2543-2019, https://doi.org/10.5194/bg-16-2543-2019, 2019
Short summary
Short summary
Mechanisms of atmospheric CO2 growth by 20 ppm from 6000 BCE to the pre-industrial period are still uncertain. We apply the Earth system model MPI-ESM-LR for two transient simulations of the climate–carbon cycle. An additional process, e.g. carbonate accumulation on shelves, is required for consistency with ice-core CO2 data. Our simulations support the hypothesis that the ocean was a source of CO2 until the late Holocene when anthropogenic CO2 sources started to affect atmospheric CO2.
Efrén López-Blanco, Jean-François Exbrayat, Magnus Lund, Torben R. Christensen, Mikkel P. Tamstorf, Darren Slevin, Gustaf Hugelius, Anthony A. Bloom, and Mathew Williams
Earth Syst. Dynam., 10, 233–255, https://doi.org/10.5194/esd-10-233-2019, https://doi.org/10.5194/esd-10-233-2019, 2019
Short summary
Short summary
The terrestrial CO2 exchange in Arctic ecosystems plays an important role in the global carbon cycle and is particularly sensitive to the ongoing warming experienced in recent years. To improve our understanding of the atmosphere–biosphere interplay, we evaluated the state of the terrestrial pan-Arctic carbon cycling using a promising data assimilation system in the first 15 years of the 21st century. This is crucial when it comes to making predictions about the future state of the carbon cycle.
Tim Eckhardt, Christian Knoblauch, Lars Kutzbach, David Holl, Gillian Simpson, Evgeny Abakumov, and Eva-Maria Pfeiffer
Biogeosciences, 16, 1543–1562, https://doi.org/10.5194/bg-16-1543-2019, https://doi.org/10.5194/bg-16-1543-2019, 2019
Short summary
Short summary
We quantified the contribution of individual components governing the net ecosystem exchange of CO2 and how these fluxes respond to environmental changes in a drained and water-saturated site in the polygonal tundra of northeast Siberia. This work finds both sites as a sink for atmospheric CO2 during the growing season, but sink strengths varied between the sites. Furthermore, it was shown that soil hydrological conditions were one of the key drivers for differing CO2 fluxes between the sites.
Anne Dallmeyer, Martin Claussen, and Victor Brovkin
Clim. Past, 15, 335–366, https://doi.org/10.5194/cp-15-335-2019, https://doi.org/10.5194/cp-15-335-2019, 2019
Short summary
Short summary
A simple but powerful method for the biomisation of plant functional type distributions is introduced and tested for six different dynamic global vegetation models based on pre-industrial and palaeo-simulations. The method facilitates the direct comparison between vegetation distributions simulated by different Earth system models and between model results and the pollen-based biome reconstructions. It is therefore a powerful tool for the evaluation of Earth system models.
Thomas Riddick, Victor Brovkin, Stefan Hagemann, and Uwe Mikolajewicz
Geosci. Model Dev., 11, 4291–4316, https://doi.org/10.5194/gmd-11-4291-2018, https://doi.org/10.5194/gmd-11-4291-2018, 2018
Short summary
Short summary
During the Last Glacial Maximum, many rivers were blocked by the presence of large ice sheets and thus found new routes to the sea. This resulted in changes in the pattern of freshwater discharge into the oceans and thus would have significantly affected ocean circulation. Also, rivers found routes across the vast exposed continental shelves to the lower coastlines of that time. We propose a model for such changes in river routing suitable for use in wider models of the last glacial cycle.
Stefano Manzoni, Petr Čapek, Philipp Porada, Martin Thurner, Mattias Winterdahl, Christian Beer, Volker Brüchert, Jan Frouz, Anke M. Herrmann, Björn D. Lindahl, Steve W. Lyon, Hana Šantrůčková, Giulia Vico, and Danielle Way
Biogeosciences, 15, 5929–5949, https://doi.org/10.5194/bg-15-5929-2018, https://doi.org/10.5194/bg-15-5929-2018, 2018
Short summary
Short summary
Carbon fixed by plants and phytoplankton through photosynthesis is ultimately stored in soils and sediments or released to the atmosphere during decomposition of dead biomass. Carbon-use efficiency is a useful metric to quantify the fate of carbon – higher efficiency means higher storage and lower release to the atmosphere. Here we summarize many definitions of carbon-use efficiency and study how this metric changes from organisms to ecosystems and from terrestrial to aquatic environments.
Josefine Walz, Christian Knoblauch, Ronja Tigges, Thomas Opel, Lutz Schirrmeister, and Eva-Maria Pfeiffer
Biogeosciences, 15, 5423–5436, https://doi.org/10.5194/bg-15-5423-2018, https://doi.org/10.5194/bg-15-5423-2018, 2018
Short summary
Short summary
We investigate potential CO2 and CH4 production in degrading ice-rich permafrost in northeastern Siberia, deposited under different climatic conditions. With laboratory incubations, it could be shown that Late Pleistocene yedoma deposits generally produced more CO2 than Holocene deposits. Thus, OM decomposability needs to be interpreted against the paleoenvironmental background. However, OM decomposability cannot be generalized solely based on the stratigraphic position.
Sandy P. Harrison, Patrick J. Bartlein, Victor Brovkin, Sander Houweling, Silvia Kloster, and I. Colin Prentice
Earth Syst. Dynam., 9, 663–677, https://doi.org/10.5194/esd-9-663-2018, https://doi.org/10.5194/esd-9-663-2018, 2018
Short summary
Short summary
Temperature affects fire occurrence and severity. Warming will increase fire-related carbon emissions and thus atmospheric CO2. The size of this feedback is not known. We use charcoal records to estimate pre-industrial fire emissions and a simple land–biosphere model to quantify the feedback. We infer a feedback strength of 5.6 3.2 ppm CO2 per degree of warming and a gain of 0.09 ± 0.05 for a climate sensitivity of 2.8 K. Thus, fire feedback is a large part of the climate–carbon-cycle feedback.
Juri Palmtag, Stefanie Cable, Hanne H. Christiansen, Gustaf Hugelius, and Peter Kuhry
The Cryosphere, 12, 1735–1744, https://doi.org/10.5194/tc-12-1735-2018, https://doi.org/10.5194/tc-12-1735-2018, 2018
Short summary
Short summary
This study aims to improve the previous soil organic carbon and total nitrogen storage estimates for the Zackenberg area (NE Greenland) that were based on a land cover classification approach, by using geomorphological upscaling. The landform-based approach more correctly constrains the depositional areas in alluvial fans and deltas with high SOC and TN storage. This research emphasises the need to consider geomorphology when assessing SOC pools in mountain permafrost landscapes.
Karel Castro-Morales, Thomas Kleinen, Sonja Kaiser, Sönke Zaehle, Fanny Kittler, Min Jung Kwon, Christian Beer, and Mathias Göckede
Biogeosciences, 15, 2691–2722, https://doi.org/10.5194/bg-15-2691-2018, https://doi.org/10.5194/bg-15-2691-2018, 2018
Short summary
Short summary
We present year-round methane emissions from wetlands in Northeast Siberia that were simulated with a land surface model. Ground-based flux measurements from the same area were used for evaluation of the model results, finding a best agreement with the observations in the summertime emissions that take place in this region predominantly through plants. During winter, methane emissions through the snow contribute 4 % of the total annual methane budget, but these are still underestimated.
Christian Beer, Philipp Porada, Altug Ekici, and Matthias Brakebusch
The Cryosphere, 12, 741–757, https://doi.org/10.5194/tc-12-741-2018, https://doi.org/10.5194/tc-12-741-2018, 2018
Short summary
Short summary
Idealized model experiments demonstrate that, in addition to a gradual climate change, changing daily to weekly variability of meteorological variables and extreme events will also have an impact on mean annual ground temperature in high-latitude permafrost areas. In fact, results of the land surface model experiments show that the projected increase of variability of meteorological variables leads to cooler permafrost soil in contrast to an otherwise soil warming in response to climate change.
Matthias Fuchs, Guido Grosse, Jens Strauss, Frank Günther, Mikhail Grigoriev, Georgy M. Maximov, and Gustaf Hugelius
Biogeosciences, 15, 953–971, https://doi.org/10.5194/bg-15-953-2018, https://doi.org/10.5194/bg-15-953-2018, 2018
Short summary
Short summary
Our paper investigates soil organic carbon and nitrogen in permafrost soils on Sobo-Sise Island and Bykovsky Peninsula in the north of eastern Siberia. We collected and analysed permafrost soil cores and upscaled carbon and nitrogen stocks to landscape level. We found large amounts of carbon and nitrogen stored in these frozen soils, reconstructed sedimentation rates and estimated the potential increase in organic carbon availability if permafrost continues to thaw and active layer deepens.
Maarit Raivonen, Sampo Smolander, Leif Backman, Jouni Susiluoto, Tuula Aalto, Tiina Markkanen, Jarmo Mäkelä, Janne Rinne, Olli Peltola, Mika Aurela, Annalea Lohila, Marin Tomasic, Xuefei Li, Tuula Larmola, Sari Juutinen, Eeva-Stiina Tuittila, Martin Heimann, Sanna Sevanto, Thomas Kleinen, Victor Brovkin, and Timo Vesala
Geosci. Model Dev., 10, 4665–4691, https://doi.org/10.5194/gmd-10-4665-2017, https://doi.org/10.5194/gmd-10-4665-2017, 2017
Short summary
Short summary
Wetlands are one of the most significant natural sources of the strong greenhouse gas methane. We developed a model that can be used within a larger wetland carbon model to simulate the methane emissions. In this study, we present the model and results of its testing. We found that the model works well with different settings and that the results depend primarily on the rate of input anoxic soil respiration and also on factors that affect the simulated oxygen concentrations in the wetland soil.
Andrey Ganopolski and Victor Brovkin
Clim. Past, 13, 1695–1716, https://doi.org/10.5194/cp-13-1695-2017, https://doi.org/10.5194/cp-13-1695-2017, 2017
Short summary
Short summary
Ice cores reveal that atmospheric CO2 concentration varied synchronously with the global ice volume. Explaining the mechanism of glacial–interglacial variations of atmospheric CO2 concentrations and the link between CO2 and ice sheets evolution still remains a challenge. Here using the Earth system model of intermediate complexity we performed for the first time simulations of co-evolution of climate, ice sheets and carbon cycle using the astronomical forcing as the only external forcing.
Sarah E. Chadburn, Gerhard Krinner, Philipp Porada, Annett Bartsch, Christian Beer, Luca Belelli Marchesini, Julia Boike, Altug Ekici, Bo Elberling, Thomas Friborg, Gustaf Hugelius, Margareta Johansson, Peter Kuhry, Lars Kutzbach, Moritz Langer, Magnus Lund, Frans-Jan W. Parmentier, Shushi Peng, Ko Van Huissteden, Tao Wang, Sebastian Westermann, Dan Zhu, and Eleanor J. Burke
Biogeosciences, 14, 5143–5169, https://doi.org/10.5194/bg-14-5143-2017, https://doi.org/10.5194/bg-14-5143-2017, 2017
Short summary
Short summary
Earth system models (ESMs) are our main tools for understanding future climate. The Arctic is important for the future carbon cycle, particularly due to the large carbon stocks in permafrost. We evaluated the performance of the land component of three major ESMs at Arctic tundra sites, focusing on the fluxes and stocks of carbon.
We show that the next steps for model improvement are to better represent vegetation dynamics, to include mosses and to improve below-ground carbon cycle processes.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Ray Weiss, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Atmos. Chem. Phys., 17, 11135–11161, https://doi.org/10.5194/acp-17-11135-2017, https://doi.org/10.5194/acp-17-11135-2017, 2017
Short summary
Short summary
Following the Global Methane Budget 2000–2012 published in Saunois et al. (2016), we use the same dataset of bottom-up and top-down approaches to discuss the variations in methane emissions over the period 2000–2012. The changes in emissions are discussed both in terms of trends and quasi-decadal changes. The ensemble gathered here allows us to synthesise the robust changes in terms of regional and sectorial contributions to the increasing methane emissions.
Jorien E. Vonk, Tommaso Tesi, Lisa Bröder, Henry Holmstrand, Gustaf Hugelius, August Andersson, Oleg Dudarev, Igor Semiletov, and Örjan Gustafsson
The Cryosphere, 11, 1879–1895, https://doi.org/10.5194/tc-11-1879-2017, https://doi.org/10.5194/tc-11-1879-2017, 2017
Sina Muster, Kurt Roth, Moritz Langer, Stephan Lange, Fabio Cresto Aleina, Annett Bartsch, Anne Morgenstern, Guido Grosse, Benjamin Jones, A. Britta K. Sannel, Ylva Sjöberg, Frank Günther, Christian Andresen, Alexandra Veremeeva, Prajna R. Lindgren, Frédéric Bouchard, Mark J. Lara, Daniel Fortier, Simon Charbonneau, Tarmo A. Virtanen, Gustaf Hugelius, Juri Palmtag, Matthias B. Siewert, William J. Riley, Charles D. Koven, and Julia Boike
Earth Syst. Sci. Data, 9, 317–348, https://doi.org/10.5194/essd-9-317-2017, https://doi.org/10.5194/essd-9-317-2017, 2017
Short summary
Short summary
Waterbodies are abundant in Arctic permafrost lowlands. Most waterbodies are ponds with a surface area smaller than 100 x 100 m. The Permafrost Region Pond and Lake Database (PeRL) for the first time maps ponds as small as 10 x 10 m. PeRL maps can be used to document changes both by comparing them to historical and future imagery. The distribution of waterbodies in the Arctic is important to know in order to manage resources in the Arctic and to improve climate predictions in the Arctic.
Daniel S. Goll, Alexander J. Winkler, Thomas Raddatz, Ning Dong, Ian Colin Prentice, Philippe Ciais, and Victor Brovkin
Geosci. Model Dev., 10, 2009–2030, https://doi.org/10.5194/gmd-10-2009-2017, https://doi.org/10.5194/gmd-10-2009-2017, 2017
Short summary
Short summary
The response of soil organic carbon decomposition to warming and the interactions between nitrogen and carbon cycling affect the feedbacks between the land carbon cycle and the climate. In the model JSBACH carbon–nitrogen interactions have only a small effect on the feedbacks, whereas modifications of soil organic carbon decomposition have a large effect. The carbon cycle in the improved model is more resilient to climatic changes than in previous version of the model.
Philipp Porada, Ulrich Pöschl, Axel Kleidon, Christian Beer, and Bettina Weber
Biogeosciences, 14, 1593–1602, https://doi.org/10.5194/bg-14-1593-2017, https://doi.org/10.5194/bg-14-1593-2017, 2017
Short summary
Short summary
Lichens and bryophytes have been shown to release nitrous oxide, which is a strong greenhouse gas and atmospheric ozone-depleting agent. Here we apply a process-based computer model of lichens and bryophytes at the global scale, to estimate growth and respiration of the organisms. By relating respiration to nitrous oxide release, we simulate global nitrous oxide emissions of 0.27 (0.19–0.35) Tg yr−1. Moreover, we quantify different sources of uncertainty in nitrous oxide emission rates.
Beniamino Abis and Victor Brovkin
Biogeosciences, 14, 511–527, https://doi.org/10.5194/bg-14-511-2017, https://doi.org/10.5194/bg-14-511-2017, 2017
Short summary
Short summary
We study the link between the boreal tree-cover fraction distribution and eight globally observed environmental factors. We find that they exert a strong control over the tree-cover distribution, generally uniquely determining its state. Furthermore, we show the location of areas with potentially alternative tree-cover states under the same environmental conditions. These areas represent transition zones with reduced resilience, where the forest can shift between different vegetation states.
Sonja Kaiser, Mathias Göckede, Karel Castro-Morales, Christian Knoblauch, Altug Ekici, Thomas Kleinen, Sebastian Zubrzycki, Torsten Sachs, Christian Wille, and Christian Beer
Geosci. Model Dev., 10, 333–358, https://doi.org/10.5194/gmd-10-333-2017, https://doi.org/10.5194/gmd-10-333-2017, 2017
Short summary
Short summary
A new consistent, process-based methane module that is integrated with permafrost processes is presented. It was developed within a global land surface scheme and evaluated at a polygonal tundra site in Samoylov, Russia. The calculated methane emissions show fair agreement with field data and capture detailed differences between the explicitly modelled gas transport processes and in the gas dynamics under varying soil water and temperature conditions during seasons and on different microsites.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Victor Brovkin, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Charles Curry, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Julia Marshall, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Catherine Prigent, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Paul Steele, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Michiel van Weele, Guido R. van der Werf, Ray Weiss, Christine Wiedinmyer, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Earth Syst. Sci. Data, 8, 697–751, https://doi.org/10.5194/essd-8-697-2016, https://doi.org/10.5194/essd-8-697-2016, 2016
Short summary
Short summary
An accurate assessment of the methane budget is important to understand the atmospheric methane concentrations and trends and to provide realistic pathways for climate change mitigation. The various and diffuse sources of methane as well and its oxidation by a very short lifetime radical challenge this assessment. We quantify the methane sources and sinks as well as their uncertainties based on both bottom-up and top-down approaches provided by a broad international scientific community.
Thomas Kleinen, Victor Brovkin, and Guy Munhoven
Clim. Past, 12, 2145–2160, https://doi.org/10.5194/cp-12-2145-2016, https://doi.org/10.5194/cp-12-2145-2016, 2016
Short summary
Short summary
We investigate trends in atmospheric CO2 during three recent interglacials – the Holocene, the Eemian and MIS 11 – using an earth system model of intermediate complexity. Our model experiments show a considerable improvement in the modelled CO2 trends for all three interglacials if peat accumulation and shallow water CaCO3 sedimentation are included, forcing the model only with orbital and sea level changes. The Holocene CO2 trend requires anthropogenic emissions of CO2 only after 3 ka BP.
Sylvia S. Nyawira, Julia E. M. S. Nabel, Axel Don, Victor Brovkin, and Julia Pongratz
Biogeosciences, 13, 5661–5675, https://doi.org/10.5194/bg-13-5661-2016, https://doi.org/10.5194/bg-13-5661-2016, 2016
Short summary
Short summary
We introduce an approach applicable to dynamic global vegetation models for evaluating simulated soil carbon changes from land-use changes against meta-analyses. The approach makes use of the large spatial coverage of the observations, and accounts for different ages of the sampled land-use transitions. The evaluation offers an opportunity for identifying causes of model–data discrepancies. Applied to the model JSBACH, we find that introducing crop harvest substantially improves the results.
Philipp Porada, Altug Ekici, and Christian Beer
The Cryosphere, 10, 2291–2315, https://doi.org/10.5194/tc-10-2291-2016, https://doi.org/10.5194/tc-10-2291-2016, 2016
Short summary
Short summary
Bryophyte and lichen cover on the forest floor at high latitudes insulates the ground and thus decreases soil temperature. This can protect permafrost soil, stabilising it against global warming. To quantify the insulating effect, we integrate a novel, process-based model of bryophyte and lichen growth into the global land surface model JSBACH. We find an average cooling effect of the bryophyte and lichen cover of 2.7 K, which implies a significant impact on soil temperature at high latitudes.
Annett Bartsch, Barbara Widhalm, Peter Kuhry, Gustaf Hugelius, Juri Palmtag, and Matthias Benjamin Siewert
Biogeosciences, 13, 5453–5470, https://doi.org/10.5194/bg-13-5453-2016, https://doi.org/10.5194/bg-13-5453-2016, 2016
Short summary
Short summary
A new approach for the estimation of soil organic carbon (SOC) pools north of the tree line has been developed based on synthetic aperture radar (SAR) data from the ENVISAT satellite. It can be shown that measurements of C-band SAR under frozen conditions represent vegetation and surface structure properties which relate to soil properties, specifically SOC. The approach provides the first spatially consistent account of soil organic carbon across the Arctic.
Christian Beer, Philipp Porada, Altug Ekici, and Matthias Brakebusch
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-210, https://doi.org/10.5194/tc-2016-210, 2016
Preprint withdrawn
Short summary
Short summary
Models suggest thawing permafrost in future due to climate change. In addition to warming, day-to-day variability of air temperature and precipitation is projected to increase. In an idealized theoretical model experiment we show that such changing short-term variability will reduce soil warming as a consequence of air warming by up to 1 K due to effects on snow and moss insulating layers. This shows the need of a mechanistic representation of such layers in Earth system models.
Ana Bastos, Philippe Ciais, Jonathan Barichivich, Laurent Bopp, Victor Brovkin, Thomas Gasser, Shushi Peng, Julia Pongratz, Nicolas Viovy, and Cathy M. Trudinger
Biogeosciences, 13, 4877–4897, https://doi.org/10.5194/bg-13-4877-2016, https://doi.org/10.5194/bg-13-4877-2016, 2016
Short summary
Short summary
The ice-core record shows a stabilisation of atmospheric CO2 in the 1940s, despite continued emissions from fossil fuel burning and land-use change (LUC). We use up-to-date reconstructions of the CO2 sources and sinks over the 20th century to evaluate whether these capture the CO2 plateau and to test the previously proposed hypothesis. Both strong terrestrial sink, possibly due to LUC not fully accounted for in the records, and enhanced oceanic uptake are necessary to explain this stall.
David M. Lawrence, George C. Hurtt, Almut Arneth, Victor Brovkin, Kate V. Calvin, Andrew D. Jones, Chris D. Jones, Peter J. Lawrence, Nathalie de Noblet-Ducoudré, Julia Pongratz, Sonia I. Seneviratne, and Elena Shevliakova
Geosci. Model Dev., 9, 2973–2998, https://doi.org/10.5194/gmd-9-2973-2016, https://doi.org/10.5194/gmd-9-2973-2016, 2016
Short summary
Short summary
Human land-use activities have resulted in large changes to the Earth's surface, with resulting implications for climate. In the future, land-use activities are likely to expand and intensify further to meet growing demands for food, fiber, and energy. The goal of LUMIP is to take the next steps in land-use change science, and enable, coordinate, and ultimately address the most important land-use science questions in more depth and sophistication than possible in a multi-model context to date.
Chris D. Jones, Vivek Arora, Pierre Friedlingstein, Laurent Bopp, Victor Brovkin, John Dunne, Heather Graven, Forrest Hoffman, Tatiana Ilyina, Jasmin G. John, Martin Jung, Michio Kawamiya, Charlie Koven, Julia Pongratz, Thomas Raddatz, James T. Randerson, and Sönke Zaehle
Geosci. Model Dev., 9, 2853–2880, https://doi.org/10.5194/gmd-9-2853-2016, https://doi.org/10.5194/gmd-9-2853-2016, 2016
Short summary
Short summary
How the carbon cycle interacts with climate will affect future climate change and how society plans emissions reductions to achieve climate targets. The Coupled Climate Carbon Cycle Model Intercomparison Project (C4MIP) is an endorsed activity of CMIP6 and aims to quantify these interactions and feedbacks in state-of-the-art climate models. This paper lays out the experimental protocol for modelling groups to follow to contribute to C4MIP. It is a contribution to the CMIP6 GMD Special Issue.
Stefan Hagemann, Tanja Blome, Altug Ekici, and Christian Beer
Earth Syst. Dynam., 7, 611–625, https://doi.org/10.5194/esd-7-611-2016, https://doi.org/10.5194/esd-7-611-2016, 2016
Short summary
Short summary
The present study analyses how cold-region physical soil processes, especially freezing of soil water, impact large-scale hydrology and climate over Northern Hemisphere high-latitude land areas. For this analysis, an atmosphere–land global climate model was used. It is shown that including these processes in the model leads to improved discharge in spring and a positive land–atmosphere feedback to precipitation over the high latitudes that has previously not been noted for the high latitudes.
Ulrike Port, Martin Claussen, and Victor Brovkin
Earth Syst. Dynam., 7, 535–547, https://doi.org/10.5194/esd-7-535-2016, https://doi.org/10.5194/esd-7-535-2016, 2016
Gustaf Hugelius, Peter Kuhry, and Charles Tarnocai
Biogeosciences, 13, 2003–2010, https://doi.org/10.5194/bg-13-2003-2016, https://doi.org/10.5194/bg-13-2003-2016, 2016
Short summary
Short summary
We investigate the properties of soils and sediments in a particular and ancient Siberian permafrost landscape. We critically examine statements from a recent study that specific permafrost landforms affected by thawed permafrost (alases) in this region contain very large quantities of peat that previous studies had failed to include because of data set biases. We conclude that there is no evidence to suggest biases in existing data sets or that alas deposits increase the northern peatland pool.
Fabio Cresto Aleina, Benjamin R. K. Runkle, Tim Brücher, Thomas Kleinen, and Victor Brovkin
Geosci. Model Dev., 9, 915–926, https://doi.org/10.5194/gmd-9-915-2016, https://doi.org/10.5194/gmd-9-915-2016, 2016
Short summary
Short summary
This study presents the hotspot parameterization, a novel approach to upscaling methane emissions in a boreal peatland from the micro-topographic scale to the landscape scale. We based this new parameterization on the analysis of water table patterns generated by the Hummock–Hollow (HH) model. We show how the hotspot parameterization successfully upscales the micro-topographic controls on methane emissions for both present-day conditions and for the next century under three different scenarios.
F. Cresto Aleina, B. R. K. Runkle, T. Kleinen, L. Kutzbach, J. Schneider, and V. Brovkin
Biogeosciences, 12, 5689–5704, https://doi.org/10.5194/bg-12-5689-2015, https://doi.org/10.5194/bg-12-5689-2015, 2015
Short summary
Short summary
We developed a process-based model for peatland micro-topography and hydrology, the Hummock-Hollow (HH) model, which explicitly represents small-scale surface elevation changes. By coupling the HH model with a model for soil methane processes, we are able to model the effects of micro-topography on hydrology and methane emissions in a typical boreal peatland. We also identify potential biases that models without a micro-topographic representation can introduce in large-scale models.
C. D. Koven, J. Q. Chambers, K. Georgiou, R. Knox, R. Negron-Juarez, W. J. Riley, V. K. Arora, V. Brovkin, P. Friedlingstein, and C. D. Jones
Biogeosciences, 12, 5211–5228, https://doi.org/10.5194/bg-12-5211-2015, https://doi.org/10.5194/bg-12-5211-2015, 2015
Short summary
Short summary
Terrestrial carbon feedbacks are a large uncertainty in climate change. We separate modeled feedback responses into those governed by changed carbon inputs (productivity) and changed outputs (turnover). The disaggregated responses show that both are important in controlling inter-model uncertainty. Interactions between productivity and turnover are also important, and research must focus on these interactions for more accurate projections of carbon cycle feedbacks.
N. Gentsch, R. Mikutta, R. J. E. Alves, J. Barta, P. Čapek, A. Gittel, G. Hugelius, P. Kuhry, N. Lashchinskiy, J. Palmtag, A. Richter, H. Šantrůčková, J. Schnecker, O. Shibistova, T. Urich, B. Wild, and G. Guggenberger
Biogeosciences, 12, 4525–4542, https://doi.org/10.5194/bg-12-4525-2015, https://doi.org/10.5194/bg-12-4525-2015, 2015
T. Schneider von Deimling, G. Grosse, J. Strauss, L. Schirrmeister, A. Morgenstern, S. Schaphoff, M. Meinshausen, and J. Boike
Biogeosciences, 12, 3469–3488, https://doi.org/10.5194/bg-12-3469-2015, https://doi.org/10.5194/bg-12-3469-2015, 2015
Short summary
Short summary
We have modelled the carbon release from thawing permafrost soils under various scenarios of future warming. Our results suggests that up to about 140Pg of carbon could be released under strong warming by end of the century. We have shown that abrupt thaw processes under thermokarst lakes can unlock large amounts of perennially frozen carbon stored in deep deposits (which extend many metres into the soil).
T. J. Bohn, J. R. Melton, A. Ito, T. Kleinen, R. Spahni, B. D. Stocker, B. Zhang, X. Zhu, R. Schroeder, M. V. Glagolev, S. Maksyutov, V. Brovkin, G. Chen, S. N. Denisov, A. V. Eliseev, A. Gallego-Sala, K. C. McDonald, M.A. Rawlins, W. J. Riley, Z. M. Subin, H. Tian, Q. Zhuang, and J. O. Kaplan
Biogeosciences, 12, 3321–3349, https://doi.org/10.5194/bg-12-3321-2015, https://doi.org/10.5194/bg-12-3321-2015, 2015
Short summary
Short summary
We evaluated 21 forward models and 5 inversions over western Siberia in terms of CH4 emissions and simulated wetland areas and compared these results to an intensive in situ CH4 flux data set, several wetland maps, and two satellite inundation products. In addition to assembling a definitive collection of methane emissions estimates for the region, we were able to identify the types of wetland maps and model features necessary for accurate simulations of high-latitude wetlands.
S. Kloster, T. Brücher, V. Brovkin, and S. Wilkenskjeld
Clim. Past, 11, 781–788, https://doi.org/10.5194/cp-11-781-2015, https://doi.org/10.5194/cp-11-781-2015, 2015
U. Port, M. Claussen, and V. Brovkin
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-997-2015, https://doi.org/10.5194/cpd-11-997-2015, 2015
Revised manuscript not accepted
M. Fuchs, P. Kuhry, and G. Hugelius
The Cryosphere, 9, 427–438, https://doi.org/10.5194/tc-9-427-2015, https://doi.org/10.5194/tc-9-427-2015, 2015
G. Hugelius, J. Strauss, S. Zubrzycki, J. W. Harden, E. A. G. Schuur, C.-L. Ping, L. Schirrmeister, G. Grosse, G. J. Michaelson, C. D. Koven, J. A. O'Donnell, B. Elberling, U. Mishra, P. Camill, Z. Yu, J. Palmtag, and P. Kuhry
Biogeosciences, 11, 6573–6593, https://doi.org/10.5194/bg-11-6573-2014, https://doi.org/10.5194/bg-11-6573-2014, 2014
Short summary
Short summary
This study provides an updated estimate of organic carbon stored in the northern permafrost region. The study includes estimates for carbon in soils (0 to 3 m depth) and deeper sediments in river deltas and the Yedoma region. We find that field data is still scarce from many regions. Total estimated carbon storage is ~1300 Pg with an uncertainty range of between 1100 and 1500 Pg. Around 800 Pg carbon is perennially frozen, equivalent to all carbon dioxide currently in the Earth's atmosphere.
F. S. E. Vamborg, V. Brovkin, and M. Claussen
Earth Syst. Dynam., 5, 89–101, https://doi.org/10.5194/esd-5-89-2014, https://doi.org/10.5194/esd-5-89-2014, 2014
G. Hugelius, J. G. Bockheim, P. Camill, B. Elberling, G. Grosse, J. W. Harden, K. Johnson, T. Jorgenson, C. D. Koven, P. Kuhry, G. Michaelson, U. Mishra, J. Palmtag, C.-L. Ping, J. O'Donnell, L. Schirrmeister, E. A. G. Schuur, Y. Sheng, L. C. Smith, J. Strauss, and Z. Yu
Earth Syst. Sci. Data, 5, 393–402, https://doi.org/10.5194/essd-5-393-2013, https://doi.org/10.5194/essd-5-393-2013, 2013
P. Dass, C. Müller, V. Brovkin, and W. Cramer
Earth Syst. Dynam., 4, 409–424, https://doi.org/10.5194/esd-4-409-2013, https://doi.org/10.5194/esd-4-409-2013, 2013
L. M. Verheijen, V. Brovkin, R. Aerts, G. Bönisch, J. H. C. Cornelissen, J. Kattge, P. B. Reich, I. J. Wright, and P. M. van Bodegom
Biogeosciences, 10, 5497–5515, https://doi.org/10.5194/bg-10-5497-2013, https://doi.org/10.5194/bg-10-5497-2013, 2013
M. Claussen, K. Selent, V. Brovkin, T. Raddatz, and V. Gayler
Biogeosciences, 10, 3593–3604, https://doi.org/10.5194/bg-10-3593-2013, https://doi.org/10.5194/bg-10-3593-2013, 2013
M. Eby, A. J. Weaver, K. Alexander, K. Zickfeld, A. Abe-Ouchi, A. A. Cimatoribus, E. Crespin, S. S. Drijfhout, N. R. Edwards, A. V. Eliseev, G. Feulner, T. Fichefet, C. E. Forest, H. Goosse, P. B. Holden, F. Joos, M. Kawamiya, D. Kicklighter, H. Kienert, K. Matsumoto, I. I. Mokhov, E. Monier, S. M. Olsen, J. O. P. Pedersen, M. Perrette, G. Philippon-Berthier, A. Ridgwell, A. Schlosser, T. Schneider von Deimling, G. Shaffer, R. S. Smith, R. Spahni, A. P. Sokolov, M. Steinacher, K. Tachiiri, K. Tokos, M. Yoshimori, N. Zeng, and F. Zhao
Clim. Past, 9, 1111–1140, https://doi.org/10.5194/cp-9-1111-2013, https://doi.org/10.5194/cp-9-1111-2013, 2013
R. Wania, J. R. Melton, E. L. Hodson, B. Poulter, B. Ringeval, R. Spahni, T. Bohn, C. A. Avis, G. Chen, A. V. Eliseev, P. O. Hopcroft, W. J. Riley, Z. M. Subin, H. Tian, P. M. van Bodegom, T. Kleinen, Z. C. Yu, J. S. Singarayer, S. Zürcher, D. P. Lettenmaier, D. J. Beerling, S. N. Denisov, C. Prigent, F. Papa, and J. O. Kaplan
Geosci. Model Dev., 6, 617–641, https://doi.org/10.5194/gmd-6-617-2013, https://doi.org/10.5194/gmd-6-617-2013, 2013
I. Preuss, C. Knoblauch, J. Gebert, and E.-M. Pfeiffer
Biogeosciences, 10, 2539–2552, https://doi.org/10.5194/bg-10-2539-2013, https://doi.org/10.5194/bg-10-2539-2013, 2013
F. Joos, R. Roth, J. S. Fuglestvedt, G. P. Peters, I. G. Enting, W. von Bloh, V. Brovkin, E. J. Burke, M. Eby, N. R. Edwards, T. Friedrich, T. L. Frölicher, P. R. Halloran, P. B. Holden, C. Jones, T. Kleinen, F. T. Mackenzie, K. Matsumoto, M. Meinshausen, G.-K. Plattner, A. Reisinger, J. Segschneider, G. Shaffer, M. Steinacher, K. Strassmann, K. Tanaka, A. Timmermann, and A. J. Weaver
Atmos. Chem. Phys., 13, 2793–2825, https://doi.org/10.5194/acp-13-2793-2013, https://doi.org/10.5194/acp-13-2793-2013, 2013
J. R. Melton, R. Wania, E. L. Hodson, B. Poulter, B. Ringeval, R. Spahni, T. Bohn, C. A. Avis, D. J. Beerling, G. Chen, A. V. Eliseev, S. N. Denisov, P. O. Hopcroft, D. P. Lettenmaier, W. J. Riley, J. S. Singarayer, Z. M. Subin, H. Tian, S. Zürcher, V. Brovkin, P. M. van Bodegom, T. Kleinen, Z. C. Yu, and J. O. Kaplan
Biogeosciences, 10, 753–788, https://doi.org/10.5194/bg-10-753-2013, https://doi.org/10.5194/bg-10-753-2013, 2013
J. Segschneider, A. Beitsch, C. Timmreck, V. Brovkin, T. Ilyina, J. Jungclaus, S. J. Lorenz, K. D. Six, and D. Zanchettin
Biogeosciences, 10, 669–687, https://doi.org/10.5194/bg-10-669-2013, https://doi.org/10.5194/bg-10-669-2013, 2013
G. Hugelius, C. Tarnocai, G. Broll, J. G. Canadell, P. Kuhry, and D. K. Swanson
Earth Syst. Sci. Data, 5, 3–13, https://doi.org/10.5194/essd-5-3-2013, https://doi.org/10.5194/essd-5-3-2013, 2013
Related subject area
Subject: Carbon Cycle | Archive: Modelling only | Timescale: Pleistocene
Assessing transient changes in the ocean carbon cycle during the last deglaciation through carbon isotope modeling
Marine carbon cycle response to a warmer Southern Ocean: the case of the last interglacial
Local oceanic CO2 outgassing triggered by terrestrial carbon fluxes during deglacial flooding
Sequential changes in ocean circulation and biological export productivity during the last glacial–interglacial cycle: a model–data study
Coupled climate–carbon cycle simulation of the Last Glacial Maximum atmospheric CO2 decrease using a large ensemble of modern plausible parameter sets
The simulated climate of the Last Glacial Maximum and insights into the global marine carbon cycle
Quantifying the ocean's role in glacial CO2 reductions
A multi-variable box model approach to the soft tissue carbon pump
Hidetaka Kobayashi, Akira Oka, Takashi Obase, and Ayako Abe-Ouchi
Clim. Past, 20, 769–787, https://doi.org/10.5194/cp-20-769-2024, https://doi.org/10.5194/cp-20-769-2024, 2024
Short summary
Short summary
This study examines the transient response of the ocean carbon cycle to climate change since the last ice age by using an ocean general circulation model. Our carbon cycle model calculates atmospheric pCO2 changes that are consistent with ice core records but whose magnitude is underestimated. Our analysis of carbon isotopes suggests that improving the expression of activated ocean ventilation and suppressing biological productivity are critical in simulating atmospheric pCO2 changes.
Dipayan Choudhury, Laurie Menviel, Katrin J. Meissner, Nicholas K. H. Yeung, Matthew Chamberlain, and Tilo Ziehn
Clim. Past, 18, 507–523, https://doi.org/10.5194/cp-18-507-2022, https://doi.org/10.5194/cp-18-507-2022, 2022
Short summary
Short summary
We investigate the effects of a warmer climate from the Earth's paleoclimate (last interglacial) on the marine carbon cycle of the Southern Ocean using a carbon-cycle-enabled state-of-the-art climate model. We find a 150 % increase in CO2 outgassing during this period, which results from competition between higher sea surface temperatures and weaker oceanic circulation. From this we unequivocally infer that the carbon uptake by the Southern Ocean will reduce under a future warming scenario.
Thomas Extier, Katharina D. Six, Bo Liu, Hanna Paulsen, and Tatiana Ilyina
Clim. Past, 18, 273–292, https://doi.org/10.5194/cp-18-273-2022, https://doi.org/10.5194/cp-18-273-2022, 2022
Short summary
Short summary
The role of land–sea fluxes during deglacial flooding in ocean biogeochemistry and CO2 exchange remains poorly constrained due to the lack of climate models that consider such fluxes. We implement the terrestrial organic matter fluxes into the ocean at a transiently changing land–sea interface in MPI-ESM and investigate their effect during the last deglaciation. Most of the terrestrial carbon goes to the ocean during flooding events of Meltwater Pulse 1a, which leads to regional CO2 outgassing.
Cameron M. O'Neill, Andrew McC. Hogg, Michael J. Ellwood, Bradley N. Opdyke, and Stephen M. Eggins
Clim. Past, 17, 171–201, https://doi.org/10.5194/cp-17-171-2021, https://doi.org/10.5194/cp-17-171-2021, 2021
Short summary
Short summary
We undertake a model–data study of the last glacial–interglacial cycle of atmospheric CO2, spanning 0–130 ka. We apply a carbon cycle box model, constrained with glacial–interglacial observations, and solve for optimal model parameter values against atmospheric and ocean proxy data. The results indicate that the last glacial drawdown in atmospheric CO2 was delivered mainly by slowing ocean circulation, lower sea surface temperatures and also increased Southern Ocean biological productivity.
Krista M. S. Kemppinen, Philip B. Holden, Neil R. Edwards, Andy Ridgwell, and Andrew D. Friend
Clim. Past, 15, 1039–1062, https://doi.org/10.5194/cp-15-1039-2019, https://doi.org/10.5194/cp-15-1039-2019, 2019
Short summary
Short summary
We simulate the Last Glacial Maximum atmospheric CO2 decrease with a large ensemble of parameter sets to investigate the range of possible physical and biogeochemical Earth system changes accompanying the CO2 decrease. Amongst the dominant ensemble changes is an increase in terrestrial carbon, which we attribute to a slower soil respiration rate, and the preservation of carbon by the LGM ice sheets. Further investigation into the role of terrestrial carbon is warranted.
Pearse J. Buchanan, Richard J. Matear, Andrew Lenton, Steven J. Phipps, Zanna Chase, and David M. Etheridge
Clim. Past, 12, 2271–2295, https://doi.org/10.5194/cp-12-2271-2016, https://doi.org/10.5194/cp-12-2271-2016, 2016
Short summary
Short summary
We quantify the contributions of physical and biogeochemical changes in the ocean to enhancing ocean carbon storage at the Last Glacial Maximum. We find that simulated circulation and surface conditions cannot explain changes in carbon storage or other major biogeochemical fields that existed during the glacial climate. Key modifications to the functioning of the biological pump are therefore required to explain the glacial climate and improve model–proxy agreement for all fields.
M. O. Chikamoto, A. Abe-Ouchi, A. Oka, R. Ohgaito, and A. Timmermann
Clim. Past, 8, 545–563, https://doi.org/10.5194/cp-8-545-2012, https://doi.org/10.5194/cp-8-545-2012, 2012
A. M. de Boer, A. J. Watson, N. R. Edwards, and K. I. C. Oliver
Clim. Past, 6, 827–841, https://doi.org/10.5194/cp-6-827-2010, https://doi.org/10.5194/cp-6-827-2010, 2010
Cited articles
Archer, D., Winguth, A., Lea, D., and Mahowald, N.: What caused the
glacial/interglacial atmospheric pCO2 cycles?, Rev. Geophys., 38,
159–189, https://doi.org/10.1029/1999RG000066, 2000.
Bauer, J., Herbst, M., Huisman, J. A., Weihermüller, L., and Vereecken,
H.: Sensitivity of simulated soil heterotrophic respiration to temperature
and moisture reduction functions, Geoderma, 145, 17–27, https://doi.org/10.1016/j.geoderma.2008.01.026, 2008.
Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N.,
Rödenbeck, C., Arain, M. A., Baldocchi, D., Bonan, G. B., Bondeau, A.,
Cescatti, A., Lasslop, G., Lindroth, A., Lomas, M., Luyssaert, S., Margolis,
H., Oleson, K. W., Roupsard, O., Veenendaal, E., Viovy, N., Williams, C.,
Woodward, F. I., and Papale, D.: Terrestrial Gross Carbon Dioxide Uptake:
Global Distribution and Covariation with Climate, Science, 329, 834–838,
https://doi.org/10.1126/science.1184984, 2010.
Beer, C.: Permafrost Sub-grid Heterogeneity of Soil Properties Key for 3-D
Soil Processes and Future Climate Projections, Front. Earth Sci., 4, 81,
https://doi.org/10.3389/feart.2016.00081, 2016.
Braakhekke, M., Beer, C., Schrumpf, M., Ekici, A., Ahrens, B., Hoosbeek
Marcel, R., Kruijt, B., Kabat, P., and Reichstein, M.: The use of
radiocarbon to constrain current and future soil organic matter turnover and
transport in a temperate forest, J. Geophys. Res.-Biogeo., 119, 372–391, https://doi.org/10.1002/2013JG002420, 2014.
Braconnot, P., Harrison, S. P., Otto-Bliesner, B., Abe-Ouchi, A., Jungclaus,
J., and Peterschmitt, J. Y.: The Paleoclimate Modeling Intercomparison
Project contribution to CMIP5, CLIVAR Exchanges, 56, 15–19, 2011.
Braconnot, P., Harrison, S. P., Kageyama, M., Bartlein, P. J.,
Masson-Delmotte, V., Abe-Ouchi, A., Otto-Bliesner, B., and Zhao, Y.:
Evaluation of climate models using palaeoclimatic data, Nat. Clim. Change, 2, 417–424,
2012.
Brovkin, V., Ganopolski, A., Archer, D., and Munhoven, G.: Glacial CO2 cycle as a
succession of key physical and biogeochemical processes, Clim. Past, 8, 251–264,
https://doi.org/10.5194/cp-8-251-2012, 2012.
Brovkin, V., Boysen, L., Raddatz, T., Gayler, V., Loew, A., and Claussen,
M.: Evaluation of vegetation cover and land-surface albedo in MPI-ESM CMIP5
simulations, J. Adv. Model. Earth Sy., 5, 48–57, https://doi.org/10.1029/2012MS000169, 2013.
Brown, J., Hinkel, K. M., and Nelson, F. E.: The circumpolar active layer
monitoring (calm) program: Research designs and initial results, Polar
Geography, 24, 166–258, https://doi.org/10.1080/10889370009377698, 2000.
Burke, E. J., Jones, C. D., and Koven, C. D.: Estimating the
Permafrost-Carbon Climate Response in the CMIP5 Climate Models Using a
Simplified Approach, J. Climate, 26, 4897–4909,
https://doi.org/10.1175/JCLI-D-12-00550.1, 2012.
Carvalhais, N., Forkel, M., Khomik, M., Bellarby, J., Jung, M., Migliavacca,
M., Mu, M., Saatchi, S., Santoro, M., Thurner, M., Weber, U.,
Ahrens, B., Beer, C., Cescatti, A., Randerson, J. T., and Reichstein, M.:
Global covariation of carbon turnover times with climate in terrestrial
ecosystems, Nature, 514, 213–217, https://doi.org/10.1038/nature13731,
2014.
Ciais, P., Tagliabue, A., Cuntz, M., Bopp, L., Scholze, M., Hoffmann, G.,
Lourantou, A., Harrison, S. P., Prentice, I. C., Kelley, D. I., Koven, C.,
and Piao, S. L.: Large inert carbon pool in the terrestrial biosphere during
the Last Glacial Maximum, Nat. Geosci, 5, 74–79, 2012.
Ciais, P., Sabine, C., Bala, G., Bopp, L., Brovkin, V., Canadell, J.,
Chhabra, A., DeFries, R., Galloway, J., Heimann, M., Jones, C., Le
Quéré, C., Myneni, R. B., Piao, S., and Thornton, P.: Carbon and
Other Biogeochemical Cycles, in: Climate Change 2013: The Physical Science
Basis. Contribution of Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin,
D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia,
Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, 2013.
Crichton, K. A., Bouttes, N., Roche, D. M., Chappellaz, J., and Krinner, G.:
Permafrost carbon as a missing link to explain CO2 changes during the last
deglaciation, Nat. Geosci., 9, 683–686, https://doi.org/10.1038/ngeo2793,
2016.
Ekici, A., Beer, C., Hagemann, S., Boike, J., Langer, M., and Hauck, C.: Simulating
high-latitude permafrost regions by the JSBACH terrestrial ecosystem model, Geosci.
Model Dev., 7, 631–647, https://doi.org/10.5194/gmd-7-631-2014, 2014.
Exbrayat, J.-F., Pitman, A. J., Zhang, Q., Abramowitz, G., and Wang, Y.-P.:
Examining soil carbon uncertainty in a global model: response of microbial
decomposition to temperature, moisture and nutrient limitation, Biogeosciences,
10, 7095–7108, https://doi.org/10.5194/bg-10-7095-2013, 2013.
Ganopolski, A., Calov, R., and Claussen, M.: Simulation of the last glacial cycle
with a coupled climate ice-sheet model of intermediate complexity, Clim. Past, 6, 229–244,
https://doi.org/10.5194/cp-6-229-2010, 2010.
Giorgetta, M. A., Jungclaus, J., Reick Christian, H., Legutke, S., Bader, J.,
Böttinger, M., Brovkin, V., Crueger, T., Esch, M., Fieg, K., Glushak, K.,
Gayler, V., Haak, H., Hollweg, H. D., Ilyina, T., Kinne, S., Kornblueh, L.,
Matei, D., Mauritsen, T., Mikolajewicz, U., Mueller, W., Notz, D., Pithan,
F., Raddatz, T., Rast, S., Redler, R., Roeckner, E., Schmidt, H., Schnur, R.,
Segschneider, J., Six Katharina, D., Stockhause, M., Timmreck, C., Wegner,
J., Widmann, H., Wieners Karl, H., Claussen, M., Marotzke, J., and Stevens,
B.: Climate and carbon cycle changes from 1850 to 2100 in MPI-ESM simulations
for the Coupled Model Intercomparison Project phase 5, J. Adv. Model. Earth
Sy., 5, 572–597, https://doi.org/10.1002/jame.20038, 2013.
Goll, D. S., Brovkin, V., Liski, J., Raddatz, T., Thum, T., and Todd-Brown,
K. E. O.: Strong dependence of CO2 emissions from anthropogenic land cover
change on initial land cover and soil carbon parametrization, Global
Biogeochem. Cy., 29, 1511–1523, https://doi.org/10.1002/2014GB004988, 2015.
Hagemann, S. and Stacke, T.: Impact of the soil hydrology scheme on
simulated soil moisture memory, Clim. Dynam., 44, 1731–1750,
https://doi.org/10.1007/s00382-014-2221-6, 2015.
Harden, J. W., Koven, C. D., Ping, C.-L., Hugelius, G., David McGuire, A.,
Camill, P., Jorgenson, T., Kuhry, P., Michaelson, G. J., O'Donnell, J. A.,
Schuur, E. A. G., Tarnocai, C., Johnson, K., and Grosse, G.: Field
information links permafrost carbon to physical vulnerabilities of thawing,
Geophys. Res. Lett., 39, L15704, https://doi.org/10.1029/2012GL051958, 2012.
Hengl, T., Mendes de Jesus, J., Heuvelink, G. B. M., Ruiperez Gonzalez, M.,
Kilibarda, M., Blagotić, A., Shangguan, W., Wright, M. N., Geng, X.,
Bauer-Marschallinger, B., Guevara, M. A., Vargas, R., MacMillan, R. A.,
Batjes, N. H., Leenaars, J. G. B., Ribeiro, E., Wheeler, I., Mantel, S., and
Kempen, B.: SoilGrids 250 m: Global gridded soil information based on machine
learning, PLOS ONE, 12, e0169748, https://doi.org/10.1371/journal.pone.0169748, 2017.
Hugelius, G., Tarnocai, C., Broll, G., Canadell, J. G., Kuhry, P., and Swanson,
D. K.: The Northern Circumpolar Soil Carbon Database: spatially distributed
datasets of soil coverage and soil carbon storage in the northern permafrost
regions, Earth Syst. Sci. Data, 5, 3–13, https://doi.org/10.5194/essd-5-3-2013, 2013.
Hugelius, G., Strauss, J., Zubrzycki, S., Harden, J. W., Schuur, E. A. G.,
Ping, C.-L., Schirrmeister, L., Grosse, G., Michaelson, G. J., Koven, C. D.,
O'Donnell, J. A., Elberling, B., Mishra, U., Camill, P., Yu, Z., Palmtag, J.,
and Kuhry, P.: Estimated stocks of circumpolar permafrost carbon with quantified
uncertainty ranges and identified data gaps, Biogeosciences, 11, 6573–6593,
https://doi.org/10.5194/bg-11-6573-2014, 2014.
Hurtt, G. C., Chini, L. P., Frolking, S., Betts, R. A., Feddema, J.,
Fischer, G., Fisk, J. P., Hibbard, K., Houghton, R. A., Janetos, A., Jones,
C. D., Kindermann, G., Kinoshita, T., Klein Goldewijk, K., Riahi, K.,
Shevliakova, E., Smith, S., Stehfest, E., Thomson, A., Thornton, P., van
Vuuren, D. P., and Wang, Y. P.: Harmonization of land-use scenarios for the
period 1500–2100: 600 years of global gridded annual land-use transitions,
wood harvest, and resulting secondary lands, Clim. Change, 109, https://doi.org/10.1007/s10584-011-0153-2,
2011.
Jackson, R. B., Lajtha, K., Crow, S. E., Hugelius, G., Kramer, M. G., and
Piñeiro, G.: The Ecology of Soil Carbon: Pools, Vulnerabilities, and
Biotic and Abiotic Controls, Annu. Rev. Ecol. Evol. S., 48, 419–445, https://doi.org/10.1146/annurev-ecolsys-112414-054234, 2017.
Jung, M., Reichstein, M., Margolis, H. A., Cescatti, A., Richardson, A. D.,
Arain, M. A., Arneth, A., Bernhofer, C., Bonal, D., Chen, J., Gianelle, D.,
Gobron, N., Kiely, G., Kutsch, W., Lasslop, G., Law, B. E., Lindroth, A.,
Merbold, L., Montagnani, L., Moors, E. J., Papale, D., Sottocornola, M.,
Vaccari, F., and Williams, C.: Global patterns of land-atmosphere fluxes of
carbon dioxide, latent heat, and sensible heat derived from eddy covariance,
satellite, and meteorological observations, J. Geophys. Res.-Biogeosci., 116, G00J07, https://doi.org/10.1029/2010JG001566, 2011.
Kageyama, M., Albani, S., Braconnot, P., Harrison, S. P., Hopcroft, P. O., Ivanovic,
R. F., Lambert, F., Marti, O., Peltier, W. R., Peterschmitt, J.-Y., Roche, D. M., Tarasov,
L., Zhang, X., Brady, E. C., Haywood, A. M., LeGrande, A. N., Lunt, D. J., Mahowald, N. M.,
Mikolajewicz, U., Nisancioglu, K. H., Otto-Bliesner, B. L., Renssen, H., Tomas, R. A., Zhang, Q.,
Abe-Ouchi, A., Bartlein, P. J., Cao, J., Li, Q., Lohmann, G., Ohgaito, R., Shi, X., Volodin, E.,
Yoshida, K., Zhang, X., and Zheng, W.: The PMIP4 contribution to CMIP6 – Part 4: Scientific
objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4
sensitivity experiments, Geosci. Model Dev., 10, 4035–4055, https://doi.org/10.5194/gmd-10-4035-2017, 2017.
Kleinen, T., Brovkin, V., and Schuldt, R. J.: A dynamic model of wetland extent and peat accumulation:
results for the Holocene, Biogeosciences, 9, 235–248, https://doi.org/10.5194/bg-9-235-2012, 2012.
Köhler, P., Knorr, G., and Bard, E.: Permafrost thawing as a possible
source of abrupt carbon release at the onset of the Bølling/Allerød,
Nat. Commun., 5, 5520, https://doi.org/10.1038/ncomms6520, 2014.
Koven, C., Friedlingstein, P., Ciais, P., Khvorostyanov, D., Krinner, G.,
and Tarnocai, C.: On the formation of high-latitude soil carbon stocks:
Effects of cryoturbation and insulation by organic matter in a land surface
model, Geophys. Res. Lett., 36, L21501, https://doi.org/10.1029/2009GL040150, 2009.
Koven, C. D., Ringeval, B., Friedlingstein, P., Ciais, P., Cadule, P.,
Khvorostyanov, D., Krinner, G., and Tarnocai, C.: Permafrost carbon-climate
feedbacks accelerate global warming, P. Natl. Acad. Sci. USA, 108, 14769–14774, 2011.
Koven, C. D., Lawrence, D. M., and Riley, W. J.: Permafrost carbon-climate
feedback is sensitive to deep soil carbon decomposability but not deep soil
nitrogen dynamics, P. Natl. Acad. Sci. USA, 112,
3752–3757, https://doi.org/10.1073/pnas.1415123112, 2015.
Langer, M., Westermann, S., Heikenfeld, M., Dorn, W., and Boike, J.:
Satellite-based modeling of permafrost temperatures in a tundra lowland
landscape, Remote Sens. Environ., 135, 12–24, https://doi.org/10.1016/j.rse.2013.03.011, 2013.
Lawrence, D. M. and Slater, A. G.: The contribution of snow condition
trends to future ground climate, Clim. Dynam., 34, 969–981, 2010.
Lawrence, D. M., Slater, A. G., and Swenson, S. C.: Simulation of Present-day
and Future Permafrost and Seasonally Frozen Ground Conditions in CCSM4, J.
Climate, 25, 2207–2225, https://doi.org/10.1175/JCLI-D-11-00334.1, 2011.
Lee, H., Sean, C. S., Andrew, G. S., and David, M. L.: Effects of excess
ground ice on projections of permafrost in a warming climate, Environ. Res.
Lett., 9, 124006, https://doi.org/10.1088/1748-9326/9/12/124006, 2014.
Lindgren, A., Hugelius, G., Kuhry, P., Christensen, T. R., and Vandenberghe,
J.: GIS-based Maps and Area Estimates of Northern Hemisphere Permafrost
Extent during the Last Glacial Maximum, Permafrost Periglac., 27, 6–16, https://doi.org/10.1002/ppp.1851, 2016.
Liski, J., Palosuo, T., Peltoniemi, M., and Sievänen, R.: Carbon and
decomposition model Yasso for forest soils, Ecol. Model., 189,
168–182, https://doi.org/10.1016/j.ecolmodel.2005.03.005, 2005.
Lourantou, A., Lavrič Jošt, V., Köhler, P., Barnola, J. M.,
Paillard, D., Michel, E., Raynaud, D., and Chappellaz, J.: Constraint of the
CO2 rise by new atmospheric carbon isotopic measurements during the
last deglaciation, Global Biogeochem. Cy., 24, GB2015,
https://doi.org/10.1029/2009GB003545, 2010.
Mauritsen, T., Bader, J., Becker, T., Behrens, J., Bittner, M., Brokopf, R.,
Brovkin, V., Claussen, M., Crueger, T., Esch, M., Fast, I., Fiedler, S.,
Fläschner, D., Gayler, V., Giorgetta, M., Goll, D., Haak, H., Hagemann,
S., Hedemann, C., Hohenegger, C., Ilyina, T., Jahns, T., Jimenez de la
Cuesta, D., Jungclaus, J., Kleinen, T., Kloster, S., Kracher, D., Kinne, S.,
Kleberg, D., Lasslop, G., Kornblueh, L., Marotzke, J., Matei, D., Meraner,
K., Mikolajewicz, U., Modali, K., Müller, W., Nabel, J., Nam, C., Notz,
D., Nyawira, S., Paulsen, H., Peters, K., Pincus, R., Pohlmann, H., Pongratz,
J., Popp, M., Raddatz, T., Rast, S., Redler, R., Reick, C., Rohrschneider,
T., Schemann, V., Schmidt, H., Schnur, R., Schulzweida, U., Six, K., Stein,
L., Stemmler, I., Stevens, B., von Storch, S., Tian, F., Voigt, A., de Vrese,
P., Wieners, K., Wilkenskjeld, S., Winkler, A., and Roeckner, E.:
Developments in the MPI-M Earth System Model version 1.2 (MPI-ESM1.2) and its
response to increasing CO2, J. Adv. Model. Earth Sy., in review,
2018.
McGuire, A. D., Anderson, L. G., Christensen, T. R., Dallimore, S., Guo, L.
D., Hayes, D. J., Heimann, M., Lorenson, T. D., Macdonald, R. W., and
Roulet, N.: Sensitivity of the carbon cycle in the Arctic to climate change,
Ecol. Monogr., 79, 523–555, 2009.
McGuire, A. D., Koven, C., Lawrence David, M., Clein Joy, S., Xia, J., Beer,
C., Burke, E., Chen, G., Chen, X., Delire, C., Jafarov, E., MacDougall
Andrew, H., Marchenko, S., Nicolsky, D., Peng, S., Rinke, A., Saito, K.,
Zhang, W., Alkama, R., Bohn Theodore, J., Ciais, P., Decharme, B., Ekici,
A., Gouttevin, I., Hajima, T., Hayes Daniel, J., Ji, D., Krinner, G.,
Lettenmaier Dennis, P., Luo, Y., Miller Paul, A., Moore John, C.,
Romanovsky, V., Schädel, C., Schaefer, K., Schuur Edward, A. G., Smith,
B., Sueyoshi, T., and Zhuang, Q.: Variability in the sensitivity among model
simulations of permafrost and carbon dynamics in the permafrost region
between 1960 and 2009, Global Biogeochem. Cy., 30, 1015–1037,
https://doi.org/10.1002/2016GB005405, 2016.
Mergelov, N. S. and Targulian, V. O.: Accumulation of organic matter in the
mineral layers of permafrost-affected soils of coastal lowlands in East
Siberia, Eurasian Soil Sci., 44, 249–260, https://doi.org/10.1134/S1064229311030069,
2011.
Mikolajewicz, U., Ziemen, F., Cioni, G., Claussen, M., Fraedrich, K., Heidkamp, M.,
Hohenegger, C., Jimenez de la Cuesta, D., Kapsch, M.-L., Lemburg, A., Mauritsen, T.,
Meraner, K., Röber, N., Schmidt, H., Six, K. D., Stemmler, I., Tamarin-Brodsky, T.,
Winkler, A., Zhu, X., and Stevens, B.: The climate of a retrograde rotating Earth,
Earth Syst. Dynam., 9, 1191–1215, https://doi.org/10.5194/esd-9-1191-2018, 2018.
O'Donnell, J. A., Romanovsky, V. E., Harden, J. W., and McGuire, A. D.: The
Effect of Moisture Content on the Thermal Conductivity of Moss and Organic
Soil Horizons From Black Spruce Ecosystems in Interior Alaska, Soil Sci.,
174, 646–651, 2009.
Pelletier, J., Broxton, P., Hazenberg, P., Zeng, X., Troch, P., Niu, G. Y.,
Williams, Z., Brunke, M., and Gochis, D.: A gridded global data set of soil,
intact regolith, and sedimentary deposit thicknesses for regional and global
land surface modeling, J. Adv. Model. Earth Sy., 8,
41–65, https://doi.org/10.1002/2015MS000526, 2016.
Porada, P., Ekici, A., and Beer, C.: Effects of bryophyte and lichen cover on
permafrost soil temperature at large scale, The Cryosphere, 10, 2291–2315,
https://doi.org/10.5194/tc-10-2291-2016, 2016.
Reick, C. H., Raddatz, T., Brovkin, V., and Gayler, V.: Representation of
natural and anthropogenic land cover change in MPI-ESM, J. Adv. Model. Earth Sy., 5, 459–482, https://doi.org/10.1002/jame.20022, 2013.
Saito, K., Sueyoshi, T., Marchenko, S., Romanovsky, V., Otto-Bliesner, B.,
Walsh, J., Bigelow, N., Hendricks, A., and Yoshikawa, K.: LGM permafrost distribution:
how well can the latest PMIP multi-model ensembles perform reconstruction?, Clim. Past, 9,
1697–1714, https://doi.org/10.5194/cp-9-1697-2013, 2013.
Schädel, C., Schuur, E. A. G., Bracho, R., Elberling, B., Knoblauch, C.,
Lee, H., Luo, Y., Shaver, G. R., and Turetsky, M. R.: Circumpolar assessment
of permafrost C quality and its vulnerability over time using long-term
incubation data, Glob. Change Biol., 20, 641–652, 10.1111/gcb.12417,
2014.
Schaefer, K., Lantuit, H., Romanovsky, V. E., Schuur, E. A. G., and Witt, R.:
The impact of the permafrost carbon feedback on global climate, Environ. Res.
Lett., 9, 085003, https://doi.org/10.1088/1748-9326/9/8/085003, 2014.
Schaphoff, S., Heyder, U., Ostberg, S., Gerten, D., Heinke, J., and Lucht,
W.: Contribution of permafrost soils to the global carbon budget, Environ.
Res. Lett., 8, 014026, https://doi.org/10.1088/1748-9326/8/1/014026, 2013.
Schmidt, G. A., Annan, J. D., Bartlein, P. J., Cook, B. I., Guilyardi, E.,
Hargreaves, J. C., Harrison, S. P., Kageyama, M., LeGrande, A. N., Konecky,
B., Lovejoy, S., Mann, M. E., Masson-Delmotte, V., Risi, C., Thompson, D.,
Timmermann, A., Tremblay, L.-B., and Yiou, P.: Using palaeo-climate
comparisons to constrain future projections in CMIP5, Clim. Past, 10,
221–250, https://doi.org/10.5194/cp-10-221-2014, 2014.
Schneck, R., Reick, C. H., and Raddatz, T.: Land contribution to natural
CO2 variability on time scales of centuries, J. Adv. Model. Earth
Sy., 5, 354–365, https://doi.org/10.1002/jame.20029, 2013.
Schneider von Deimling, T., Meinshausen, M., Levermann, A., Huber, V., Frieler, K.,
Lawrence, D. M., and Brovkin, V.: Estimating the near-surface permafrost-carbon feedback
on global warming, Biogeosciences, 9, 649–665, https://doi.org/10.5194/bg-9-649-2012, 2012.
Schneider von Deimling, T., Grosse, G., Strauss, J., Schirrmeister, L.,
Morgenstern, A., Schaphoff, S., Meinshausen, M., and Boike, J.:
Observation-based modelling of permafrost carbon fluxes with accounting for
deep carbon deposits and thermokarst activity, Biogeosciences, 12,
3469–3488, https://doi.org/10.5194/bg-12-3469-2015, 2015.
Slater, A. G. and Lawrence, D. M.: Diagnosing Present and Future Permafrost
from Climate Models, J. Climate, 26, 5608–5623,
https://doi.org/10.1175/JCLI-D-12-00341.1, 2013.
Stieglitz, M., Déry, S. J., Romanovsky, V. E., and Osterkamp, T. E.: The
role of snow cover in the warming of arctic permafrost, Geophys. Res. Lett.,
30, 1721, https://doi.org/10.1029/2003GL017337, 2003.
Strauss, J., Schirrmeister, L., Grosse, G., Fortier, D., Hugelius, G.,
Knoblauch, C., Romanovsky, V., Schädel, C., Schneider von Deimling, T.,
Schuur, E. A. G., Shmelev, D., Ulrich, M., and Veremeeva, A.: Deep Yedoma
permafrost: A synthesis of depositional characteristics and carbon
vulnerability, Earth-Sci. Rev., 172, 75–86,
https://doi.org/10.1016/j.earscirev.2017.07.007, 2017.
Thum, T., Räisänen, P., Sevanto, S., Tuomi, M., Reick, C., Vesala,
T., Raddatz, T., Aalto, T., Järvinen, H., Altimir, N., Pilegaard, K.,
Nagy, Z., Rambal, S., and Liski, J.: Soil carbon model alternatives for
ECHAM5/JSBACH climate model: Evaluation and impacts on global carbon cycle
estimates, J. Geophys. Res.-Biogeosci., 116, G02028,
https://doi.org/10.1029/2010JG001612, 2011.
Tuomi, M., Thum, T., Järvinen, H., Fronzek, S., Berg, B., Harmon, M.,
Trofymow, J. A., Sevanto, S., and Liski, J.: Leaf litter decomposition –
Estimates of global variability based on Yasso07 model, Ecol. Model., 220,
3362–3371, https://doi.org/10.1016/j.ecolmodel.2009.05.016, 2009.
Walter, K. M., Edwards, M. E., Grosse, G., Zimov, S. A., and Chapin, F. S.:
Thermokarst lakes as a source of atmospheric CH4 during the last
deglaciation, Science, 318, 633–636, 2007.
Walz, J., Knoblauch, C., Böhme, L., and Pfeiffer, E.-M.: Regulation of
soil organic matter decomposition in permafrost-affected Siberian tundra
soils – Impact of oxygen availability, freezing and thawing, temperature,
and labile organic matter, Soil Biol. Biochem., 110, 34–43,
https://doi.org/10.1016/j.soilbio.2017.03.001, 2017.
Willeit, M. and Ganopolski, A.: Coupled Northern Hemisphere
permafrost-ice-sheet evolution over the last glacial cycle, Clim. Past, 11,
1165–1180, https://doi.org/10.5194/cp-11-1165-2015, 2015.
Xu, X., Shi, Z., Li, D., Rey, A., Ruan, H., Craine, J. M., Liang, J., Zhou,
J., and Luo, Y.: Soil properties control decomposition of soil organic
carbon: Results from data-assimilation analysis, Geoderma, 262, 235–242,
https://doi.org/10.1016/j.geoderma.2015.08.038, 2016.
Yu, Z., Loisel, J., Brosseau Daniel, P., Beilman David, W., and Hunt
Stephanie, J.: Global peatland dynamics since the Last Glacial Maximum,
Geophys. Res. Lett., 37, L13402, https://doi.org/10.1029/2010GL043584, 2010.
Zech, R., Huang, Y., Zech, M., Tarozo, R., and Zech, W.: High carbon
sequestration in Siberian permafrost loess-paleosols during glacials, Clim.
Past, 7, 501–509, https://doi.org/10.5194/cp-7-501-2011, 2011.
Zhang, T., Barry, R. G., Knowles, K., Heginbottom, J. A., and Brown, J.:
Statistics and characteristics of permafrost and ground-ice distribution in
the Northern Hemisphere, Polar Geogr., 23, 132–154,
https://doi.org/10.1080/10889379909377670, 1999.
Zhang, T.: Influence of the seasonal snow cover on the ground thermal regime:
An overview, Rev. Geophys., 43, RG4002, https://doi.org/10.1029/2004RG000157, 2005.
Zhang, T., Barry, R. G., Knowles, K., Heginbottom, J. A., and Brown, J.:
Statistics and characteristics of permafrost and ground-ice distribution in
the Northern Hemisphere, Polar Geogr., 31, 47–68,
https://doi.org/10.1080/10889370802175895, 2008.
Zhu, D., Peng, S., Ciais, P., Zech, R., Krinner, G., Zimov, S., and Grosse,
G.: Simulating soil organic carbon in yedoma deposits during the Last Glacial
Maximum in a land surface model, Geophys. Res. Lett., 43, 5133–5142,
https://doi.org/10.1002/2016GL068874, 2016.
Zimov, S. A., Davydov, S. P., Zimova, G. M., Davydova, A. I., Schuur, E. A.
G., Dutta, K., and Chapin, F. S.: Permafrost carbon: Stock and
decomposability of a globally significant carbon pool, Geophys. Res. Lett.,
33, L20502, https://doi.org/10.1029/2006GL027484, 2006.
Short summary
Past cold ice age temperatures and the subsequent warming towards the Holocene had large consequences for soil organic carbon (SOC) stored in perennially frozen grounds. Using an Earth system model we show how the spread in areas affected by permafrost have changed under deglacial warming, along with changes in SOC accumulation. Our model simulations suggest phases of circum-Arctic permafrost SOC gain and losses, with a net increase in SOC between the last glacial maximum and the pre-industrial.
Past cold ice age temperatures and the subsequent warming towards the Holocene had large...
