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18 results on '"Ben Poulter"'

1. Response of global land evapotranspiration to climate change, elevated CO2, and land use change

Author

Pierre Friedlingstein, Dongdong Kong, Danica Lombardozzi, Ben Poulter, Atul K. Jain, Jianfeng Li, Yuanyuan You, Hanqin Tian, Julia E. M. S. Nabel, Xingyu Feng, Xihui Gu, Jianyu Liu, Almut Arneth, Ming Luo, Stephen Sitch, University of South Alabama, University of Exeter, Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, National Center for Atmospheric Research [Boulder] (NCAR), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
Atmospheric Science, Global and Planetary Change, 010504 meteorology & atmospheric sciences, 0207 environmental engineering, Tropics, Climate change, Forestry, 02 engineering and technology, Global ecosystem, 15. Life on land, 01 natural sciences, 13. Climate action, Climatology, Evapotranspiration, General Circulation Model, [SDE]Environmental Sciences, Temperate climate, Environmental science, Land use, land-use change and forestry, Precipitation, 020701 environmental engineering, Agronomy and Crop Science, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Climate change (CLI), elevated CO2 concentration (CO2), and land use change (LUC) have strongly altered land evapotranspiration (ET) during the recent decades. The fingerprints of these drivers in ET change, however, have not previously been detected due to the lack of these three scenarios from global climate models (GCMs). Here we applied an optimal fingerprint method to detect and attribute ET change by integrated utilization of state-of-the-art global ecosystem models and GCMs. Results indicate that CLI provides the greatest contribution to increasing ET, and its fingerprint is detectable at different timescales. CO2 reduces ET in most areas covered by forests. LUC decreases ET over the tropics, while increases ET over temperate and high-latitude regions. To further subdivide the impacts of CLI, we extend the Budyko framework to quantify the contribution of precipitation (P) and potential evapotranspiration (PET) and find that the dominant role of CLI mainly depends on the contribution of P.

Published
2021

2. Forest responses to last-millennium hydroclimate variability are governed by spatial variations in ecosystem sensitivity

Author

Ann Raiho, Christine R. Rollinson, Thomas Hickler, David J. P. Moore, Stephen T. Jackson, Mathias Trachsel, Andria Dawson, Jason S. McLachlan, John W. Williams, Michael Dietze, Ben Poulter, Jörg Steinkamp, and Tristan Quaife

Subjects
0106 biological sciences, Biomass (ecology), Ecology, 010604 marine biology & hydrobiology, Climate Change, Biodiversity, Climate change, Forest change, Forests, 010603 evolutionary biology, 01 natural sciences, Droughts, Trees, Ecosystem model, Climatology, Spatial ecology, Environmental science, Ecosystem, Sensitivity (control systems), Ecology, Evolution, Behavior and Systematics
Abstract

Forecasts of forest responses to climate variability are governed by climate exposure and ecosystem sensitivity, but ecosystem model projections and process representations are under-constrained by data at multidecadal and longer timescales. Here, we assess ecosystem sensitivity to centennial-scale hydroclimate variability, by comparing dendroclimatic and pollen-inferred reconstructions of drought, forest composition and biomass for the last millennium with five ecosystem model simulations. In both observations and models, spatial patterns in ecosystem responses to hydroclimate variability are strongly governed by ecosystem sensitivity rather than climate exposure. Ecosystem sensitivity was highest in simpler models and higher than observations, suggesting that interactions among biodiversity, demography, and ecophysiology processes dampen the sensitivity of forest composition and biomass to climate variability and change. By integrating ecosystem models with observations from timescales extending beyond the instrumental record, we can better understand and forecast the mechanisms regulating forest sensitivity to climate variability in a complex and changing world.

Published
2020

3. Comment on 'The global tree restoration potential'

Author

Simon L. Lewis, Edward T. A. Mitchard, Colin Prentice, Mark Maslin, and Ben Poulter

Subjects
0106 biological sciences, Multidisciplinary, 010504 meteorology & atmospheric sciences, 13. Climate action, General Science & Technology, Climate Change, 15. Life on land, Forests, 010603 evolutionary biology, 01 natural sciences, Carbon, 0105 earth and related environmental sciences, Trees
Abstract

Bastin et al . (Reports, 5 July 2019, p. 76) state that the restoration potential of new forests globally is 205 gigatonnes of carbon, conclude that “global tree restoration is our most effective climate change solution to date,” and state that climate change will drive the loss of 450 million hectares of existing tropical forest by 2050. Here we show that these three statements are incorrect.

Published
2019

4. Role of CO2, climate and land use in regulating the seasonal amplitude increase of carbon fluxes in terrestrial ecosystems: a multimodel analysis

Author

Shijie Shu, Stephen Sitch, Pierre Friedlingstein, Andy Wiltshire, Fang Zhao, Rashid Rafique, Atul K. Jain, Sönke Zaehle, Nicolas Viovy, Ben Poulter, Ning Zeng, Charles D. Koven, Eugenia Kalnay, Beni Stocker, Etsushi Kato, Ghassem R. Asrar, and Akihiko Ito

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Carbon sink, Climate change, 15. Life on land, Seasonality, medicine.disease, Dynamic global vegetation model, 01 natural sciences, Carbon cycle, 13. Climate action, Climatology, Temperate climate, Spatial ecology, medicine, Environmental science, Terrestrial ecosystem, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract

We examined the net terrestrial carbon flux to the atmosphere (FTA) simulated by nine models from the TRENDY dynamic global vegetation model project for its seasonal cycle and amplitude trend during 1961–2012. While some models exhibit similar phase and amplitude compared to atmospheric inversions, with spring drawdown and autumn rebound, others tend to rebound early in summer. The model ensemble mean underestimates the magnitude of the seasonal cycle by 40 % compared to atmospheric inversions. Global FTA amplitude increase (19 ± 8 %) and its decadal variability from the model ensemble are generally consistent with constraints from surface atmosphere observations. However, models disagree on attribution of this long-term amplitude increase, with factorial experiments attributing 83 ± 56 %, −3 ± 74 and 20 ± 30 % to rising CO2, climate change and land use/cover change, respectively. Seven out of the nine models suggest that CO2 fertilization is the strongest control – with the notable exception of VEGAS, which attributes approximately equally to the three factors. Generally, all models display an enhanced seasonality over the boreal region in response to high-latitude warming, but a negative climate contribution from part of the Northern Hemisphere temperate region, and the net result is a divergence over climate change effect. Six of the nine models show that land use/cover change amplifies the seasonal cycle of global FTA: some are due to forest regrowth, while others are caused by crop expansion or agricultural intensification, as revealed by their divergent spatial patterns. We also discovered a moderate cross-model correlation between FTA amplitude increase and increase in land carbon sink (R2 = 0.61). Our results suggest that models can show similar results in some benchmarks with different underlying mechanisms; therefore, the spatial traits of CO2 fertilization, climate change and land use/cover changes are crucial in determining the right mechanisms in seasonal carbon cycle change as well as mean sink change.

Published
2016

5. The relative importance of intrinsic and extrinsic factors in the decline of obligate seeder forests

Author

David M. J. S. Bowman, Grant J. Williamson, Lynda D. Prior, Brett P. Murphy, and Ben Poulter

Subjects
0106 biological sciences, Global and Planetary Change, 010504 meteorology & atmospheric sciences, Ecology, biology, Obligate, Climate oscillation, Climate change, 15. Life on land, biology.organism_classification, Seeder, 010603 evolutionary biology, 01 natural sciences, Eucalyptus, 13. Climate action, Alternative stable state, Local extinction, Eucalyptus delegatensis, Environmental science, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract

Forests that regenerate exclusively from seed following high-severity fire are particularly vulnerable to local extinction if fire frequency leaves insufficient time for regenerating plants to reach sexual maturity. We evaluate the relative importance of extrinsic (such as fire weather and climate cycles) and intrinsic (such as proneness to fire due to stand age and structural development) factors in driving the decline of obligate seeder forests. We illustrate this using obligate seeding alpine ash (Eucalyptus delegatensis) forests in the montane regions of Victoria, Australia, that were burnt by megafires in 2003 (142,256 ha) or 2007 (79,902 ha), including some twice-burnt areas (11,599 ha). Geospatial analyses showed only a small effect of stand age on the remote sensing estimates of crown defoliation, but a substantial effect of forest fire weather, as measured by forest fire danger index (FFDI). Analysis of meteorological data over the last century showed that 5-year increases in FFDI precede cycle major fires in the E. delegatensis forests. Such strong extrinsic climate/weather driving of high-severity fires is consistent with the ‘interval squeeze model’ that postulates the vulnerability of obligate seeder forests to landscape-scale demographic collapse in response to worsening fire weather under climate change.

Published
2016

6. Land-use emissions play a critical role in land-based mitigation for Paris climate targets

Author

Stephen Sitch, Philippe Ciais, Andreas Krause, Peter M. Cox, Eddy Robertson, Atul K. Jain, William J. Collins, Garry Hayman, Lena Boysen, Christopher P. Webber, Timothy M. Lenton, Eleanor J. Burke, N. Devaraju, Jonathan C. Doelman, Edward Comyn-Platt, Sarah Chadburn, Anna B. Harper, Detlef P. van Vuuren, Vassilis Daioglou, Chris Huntingford, Ben Poulter, Ana Bastos, Joanna Isobel House, Andy Wiltshire, Tom Powell, Shijie Shu, College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, College of Life and Environmental Sciences, University of Exeter, School of Geographical Sciences [Bristol], University of Bristol [Bristol], Centre for Ecology and Hydrology [Wallingford] (CEH), Natural Environment Research Council (NERC), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], University of Leeds, Department of Meteorology [Reading], University of Reading (UOR), PBL Netherlands Environmental Assessment Agency, Department of Geography [München], Ludwig-Maximilians-Universität München (LMU), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Department of Atmospheric Sciences [Urbana], University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Institute of Nanotechnology [Karlsruhe] (INT), Karlsruhe Institute of Technology (KIT), NASA Goddard Space Flight Center (GSFC), European Project: 641816,H2020,H2020-SC5-2014-two-stage,CRESCENDO(2015), European Project: 603542,EC:FP7:ENV,FP7-ENV-2013-two-stage,LUC4C(2013), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Life on Land, Science, General Physics and Astronomy, Climate change, 010501 environmental sciences, Carbon sequestration, 01 natural sciences, 7. Clean energy, General Biochemistry, Genetics and Molecular Biology, Article, Meteorology and Climatology, Affordable and Clean Energy, Environmental protection, Deforestation, 11. Sustainability, Carbon capture and storage, ddc:550, lcsh:Science, 0105 earth and related environmental sciences, Multidisciplinary, Global warming, Reforestation, Bio-energy with carbon capture and storage, General Chemistry, Soil carbon, 15. Life on land, Climate Action, Earth sciences, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, [SDE]Environmental Sciences, Environmental science, lcsh:Q
Abstract

Scenarios that limit global warming to below 2 °C by 2100 assume significant land-use change to support large-scale carbon dioxide (CO2) removal from the atmosphere by afforestation/reforestation, avoided deforestation, and Biomass Energy with Carbon Capture and Storage (BECCS). The more ambitious mitigation scenarios require even greater land area for mitigation and/or earlier adoption of CO2 removal strategies. Here we show that additional land-use change to meet a 1.5 °C climate change target could result in net losses of carbon from the land. The effectiveness of BECCS strongly depends on several assumptions related to the choice of biomass, the fate of initial above ground biomass, and the fossil-fuel emissions offset in the energy system. Depending on these factors, carbon removed from the atmosphere through BECCS could easily be offset by losses due to land-use change. If BECCS involves replacing high-carbon content ecosystems with crops, then forest-based mitigation could be more efficient for atmospheric CO2 removal than BECCS., Land-based mitigation for meeting the Paris climate target must consider the carbon cycle impacts of land-use change. Here the authors show that when bioenergy crops replace high carbon content ecosystems, forest-based mitigation could be more effective for CO2 removal than bioenergy crops with carbon capture and storage.

Published
2018

7. Change in terrestrial ecosystem water‐use efficiency over the last three decades

Author

Xiaoying Shi, Lei Cheng, Jiafu Mao, Mengtian Huang, Philippe Ciais, Shilong Piao, Yan Sun, Ben Poulter, Ying-Ping Wang, Zhenzhong Zeng, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University [Beijing], ICOS-ATC (ICOS-ATC), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), CSIRO Land and Water, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, Montana State University (MSU), Oceans and Atmosphere Flagship [Brisbane], and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nitrogen deposition, Nitrogen, Climate Change, Climate change, Carbon Cycle, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Environmental Chemistry, Photosynthesis, Water-use efficiency, China, Ecosystem, General Environmental Science, Hydrology, Global and Planetary Change, Ecology, business.industry, Environmental resource management, Water, Environmental research, Plant Transpiration, Carbon Dioxide, Models, Theoretical, Plants, 15. Life on land, 13. Climate action, Environmental science, Christian ministry, Terrestrial ecosystem, [SDV.EE.BIO]Life Sciences [q-bio]/Ecology, environment/Bioclimatology, business
Abstract

Defined as the ratio between gross primary productivity (GPP) and evapotranspiration (ET), ecosystem-scale water-use efficiency (EWUE) is an indicator of the adjustment of vegetation photosynthesis to water loss. The processes controlling EWUE are complex and reflect both a slow evolution of plants and plant communities as well as fast adjustments of ecosystem functioning to changes of limiting resources. In this study, we investigated EWUE trends from 1982 to 2008 using data-driven models derived from satellite observations and process-oriented carbon cycle models. Our findings suggest positive EWUE trends of 0.0056, 0.0007 and 0.0001 g C m(-2) mm(-1) yr(-1) under the single effect of rising CO2 ('CO2 '), climate change ('CLIM') and nitrogen deposition ('NDEP'), respectively. Global patterns of EWUE trends under different scenarios suggest that (i) EWUE-CO2 shows global increases, (ii) EWUE-CLIM increases in mainly high latitudes and decreases at middle and low latitudes, (iii) EWUE-NDEP displays slight increasing trends except in west Siberia, eastern Europe, parts of North America and central Amazonia. The data-driven MTE model, however, shows a slight decline of EWUE during the same period (-0.0005 g C m(-2) mm(-1) yr(-1) ), which differs from process-model (0.0064 g C m(-2) mm(-1) yr(-1) ) simulations with all drivers taken into account. We attribute this discrepancy to the fact that the nonmodeled physiological effects of elevated CO2 reducing stomatal conductance and transpiration (TR) in the MTE model. Partial correlation analysis between EWUE and climate drivers shows similar responses to climatic variables with the data-driven model and the process-oriented models across different ecosystems. Change in water-use efficiency defined from transpiration-based WUEt (GPP/TR) and inherent water-use efficiency (IWUEt , GPP×VPD/TR) in response to rising CO2 , climate change, and nitrogen deposition are also discussed. Our analyses will facilitate mechanistic understanding of the carbon-water interactions over terrestrial ecosystems under global change.

Published
2015

8. Detection and attribution of vegetation greening trend in China over the last 30 years

Author

Ying-Ping Wang, Ronggao Liu, Ranga B. Myneni, Shushi Peng, Lei Cheng, Mengtian Huang, Shilong Piao, Ning Zeng, Xiaoying Shi, Guodong Yin, Jiafu Mao, Jianguang Tan, Ben Poulter, Zhenzhong Zeng, Zhiqiang Xiao, and Yue Li

Subjects
China, Conservation of Natural Resources, Nitrogen, Climate Change, Plant Development, Climate change, Forests, Greening, Effects of global warming, Environmental Chemistry, Ecosystem, Spacecraft, Leaf area index, General Environmental Science, Global and Planetary Change, Ecology, Temperature, Primary production, Vegetation, Carbon Dioxide, Models, Theoretical, Geography, Climatology, Remote Sensing Technology, Spatial ecology, Environmental Monitoring
Abstract

The reliable detection and attribution of changes in vegetation growth is a prerequisite for the development of strategies for the sustainable management of ecosystems. This is an extraordinary challenge. To our knowledge, this study is the first to comprehensively detect and attribute a greening trend in China over the last three decades. We use three different satellite-derived Leaf Area Index (LAI) datasets for detection as well as five different process-based ecosystem models for attribution. Rising atmospheric CO2 concentration and nitrogen deposition are identified as the most likely causes of the greening trend in China, explaining 85% and 41% of the average growing-season LAI trend (LAIGS) estimated by satellite datasets (average trend of 0.0070 yr(-1), ranging from 0.0035 yr(-1) to 0.0127 yr(-1)), respectively. The contribution of nitrogen deposition is more clearly seen in southern China than in the north of the country. Models disagree about the contribution of climate change alone to the trend in LAIGS at the country scale (one model shows a significant increasing trend, whereas two others show significant decreasing trends). However, the models generally agree on the negative impacts of climate change in north China and Inner Mongolia and the positive impact in the Qinghai-Xizang plateau. Provincial forest area change tends to be significantly correlated with the trend of LAIGS (P < 0.05), and marginally significantly (P = 0.07) correlated with the residual of LAIGS trend, calculated as the trend observed by satellite minus that estimated by models through considering the effects of climate change, rising CO2 concentration and nitrogen deposition, across different provinces. This result highlights the important role of China's afforestation program in explaining the spatial patterns of trend in vegetation growth.

Published
2015

9. Higher temperature variability reduces temperature sensitivity of vegetation growth in Northern Hemisphere

Author

Xiao-Yan Li, Xiuchen Wu, Yi Yin, Nicolas Vuichard, Pei Wang, Weichao Guo, Yongmei Huang, Shilong Piao, Hongyan Liu, Ben Poulter, Changhui Peng, Philippe Ciais, Nicolas Viovy, Beijing Normal University (BNU), College of Urban and Environmental Sciences [Beijing], Peking University [Beijing], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Montana State University (MSU), Université du Québec à Montréal = University of Québec in Montréal (UQAM), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, 010504 meteorology & atmospheric sciences, ved/biology.organism_classification_rank.species, Climate change, 01 natural sciences, Shrub, Normalized Difference Vegetation Index, Latitude, 03 medical and health sciences, Ecosystem model, medicine, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, ved/biology, Global warming, Northern Hemisphere, 15. Life on land, 030104 developmental biology, Geophysics, 13. Climate action, Climatology, General Earth and Planetary Sciences, Environmental science, medicine.symptom, Vegetation (pathology)
Abstract

Interannual air temperature variability has changed over some regions in Northern Hemisphere (NH), accompanying with climate warming. However, whether and to what extent it regulates the interannual sensitivity of vegetation growth to temperature variability (i.e., interannual temperature sensitivity)—one central issue in understanding and predicting the responses of vegetation growth to changing climate—still remains poorly quantified and understood. Here we quantify the relationships between the interannual temperature sensitivity of mean growing-season (April–October) normalized difference vegetation index (NDVI) and ecosystem model simulations of gross primary productivity (GPP), and variability in mean growing-season temperature for forest, shrub, and grass over NH. We find that higher interannual variability in mean growing-season temperature leads to consistent decrease in interannual temperature sensitivity of mean growing-season NDVI among all vegetation types but not in model simulations of GPP. Drier condition associates with ~130 ± 150% further decrease in interannual temperature sensitivity of mean growing-season NDVI by temperature variability in forest and shrub. These results illustrate that varying temperature variability can significantly regulate the interannual temperature sensitivity of vegetation growth over NH, interacted with drought variability and nonlinear responses of photosynthesis to temperature. Our findings call for an improved characterization of the nonlinear effects of temperature variability on vegetation growth within global ecosystem models.

Published
2017

10. Spatial variability and temporal trends in water-use efficiency of European forests

Author

Tom Levanič, Ben Poulter, John S. Waterhouse, Emilia Gutiérrez, David Frank, Danny McCarroll, Iain Robertson, Laia Andreu-Hayles, Håkan Grudd, Tatjana Boettger, Fortunat Joos, Gerd Helle, Peter M. Wynn, Ingo Heinrich, Isabel Dorado Liñán, Markus Leuenberger, Emmi Hilasvuori, Giles H.F. Young, Eloni Sonninen, Matthias Saurer, Kerstin Treydte, Ewan J. Woodley, Ian J. Fairchild, Rolf T. W. Siegwolf, Mary Gagen, Risto Jalkanen, Hans W. Linderholm, Renato Spahni, Michael Friedrich, Marika Haupt, Neil J. Loader, Paul Scherrer Institute, Villigen, Oeschger Centre for Climate Change Research (OCCR), University of Bern, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Department of Geography [Swansea], Swansea University, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), Universitat de Barcelona (UB), University of Birmingham [Birmingham], University of Hohenheim, Finnish Museum of Natural History (LUOMUS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Bolin Centre for Climate Research, Stockholm University, Finnish Forest Research Institute (METLA), Natural Resources Institute Finland (LUKE), Slovenian Forestry Institute, University of Gothenburg (GU), Anglia Ruskin University (ARU), Lancaster Environment Centre, Lancaster University, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Helsinki, and Universitat de Barcelona

Subjects
0106 biological sciences, Stomatal conductance, Time Factors, Dendrochronology, 010504 meteorology & atmospheric sciences, Climate Change, ta1171, Climate change, Forests, Atmospheric sciences, 01 natural sciences, Carbon Cycle, Trees, Water Cycle, Canvi climàtic, Environmental Chemistry, Ecosystem, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Dendrocronologia, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, General Environmental Science, Hydrology, Climatology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Carbon Isotopes, Global and Planetary Change, Geography, Ecology, Boscos, Vegetation, Carbon Dioxide, Models, Theoretical, 15. Life on land, Climatic changes, ta4112, Climatic change, Europe, 13. Climate action, Climatologia, Spatial ecology, Common spatial pattern, Spatial variability, Europa, Temperate rainforest, 010606 plant biology & botany, Canvis climàtics
Abstract

The increasing carbon dioxide (CO2) concentration in the atmosphere in combination with climatic changes throughout the last century are likely to have had a profound effect on the physiology of trees: altering the carbon and water fluxes passing through the stomatal pores. However, the magnitude and spatial patterns of such changes in natural forests remain highly uncertain. Here, stable carbon isotope ratios from a network of 35 tree-ring sites located across Europe are investigated to determine the intrinsic water-use efficiency (iWUE), the ratio of photosynthesis to stomatal conductance from 19012000. The results were compared with simulations of a dynamic vegetation model (LPX-Bern 1.0) that integrates numerous ecosystem and landatmosphere exchange processes in a theoretical framework. The spatial pattern of tree-ring derived iWUE of the investigated coniferous and deciduous species and the model results agreed significantly with a clear south-to-north gradient, as well as a general increase in iWUE over the 20th century. The magnitude of the iWUE increase was not spatially uniform, with the strongest increase observed and modelled for temperate forests in Central Europe, a region where summer soil-water availability decreased over the last century. We were able to demonstrate that the combined effects of increasing CO2 and climate change leading to soil drying have resulted in an accelerated increase of iWUE. These findings will help to reduce uncertainties in the land surface schemes of global climate models, where vegetationclimate feedbacks are currently still poorly constrained by observational data.

Published
2014
Full Text
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11. The global methane budget 2000-2012

Author

Akihiko Ito, Philippe Ciais, Peter Bergamaschi, Greet Janssens-Maenhout, David J. Beerling, Cyril Crevoisier, Philippe Bousquet, Julia Marshall, Simona Castaldi, Isabelle Pison, Heon Sook Kim, Yasunori Tohjima, Jean-Francois Lamarque, Atsushi Takizawa, Charles L. Curry, Debra Wunch, Kyle C. McDonald, Michel Ramonet, David Bastviken, Simon O'Doherty, Josep G. Canadell, Robin Locatelli, Francesco N. Tubiello, Prabir K. Patra, P. Steele, Brett F. Thornton, Catherine Prigent, Sander Houweling, Toshinobu Machida, David J. Wilton, Joe R. Melton, Ronald G. Prinn, William J. Riley, Edward J. Dlugokencky, Monia Santini, Giuseppe Etiope, Doug Worthy, Guido R. van der Werf, Christian Frankenberg, Shushi Peng, Vivek K. Arora, Patrick M. Crill, Ray F. Weiss, Nicolas Viovy, Michiel van Weele, Anna Peregon, Shamil Maksyutov, Vaishali Naik, Zhen Zhang, Thomas Kleinen, Lori Bruhwiler, Yukio Yoshida, Lena Höglund-Isaksson, Kristofer R. Covey, Fortunat Joos, Misa Ishizawa, Bowen Zhang, Christine Wiedinmyer, Ronny Schroeder, Nicola Gedney, Hanqin Tian, Changhui Peng, Apostolos Voulgarakis, Mihai Alexe, Victor Brovkin, Ray L. Langenfelds, Isamu Morino, Glen P. Peters, Xiyan Xu, Andy Wiltshire, Isobel J. Simpson, Ben Poulter, Marielle Saunois, Qiuan Zhu, Donald R. Blake, Paul B. Krummel, Frans-Jan W. Parmentier, Makoto Saito, Gordon Brailsford, Robert B. Jackson, Renato Spahni, Earth and Climate, Hydrology and Geo-environmental sciences, Faculty of Earth and Life Sciences, Saunois, Marielle, Bousquet, Philippe, Poulter, Ben, Peregon, Anna, Ciais, Philippe, Canadell Josep, G, Dlugokencky Edward, J., Etiope, Giuseppe, Bastviken, David, Houweling, Sander, Janssens Maenhout, Greet, Tubiello Francesco, N., Castaldi, Simona, Jackson Robert, B., Alexe, Mihai, Arora Vivek, K., Beerling David, J., Bergamaschi, Peter, Blake Donald, R., Brailsford, Gordon, Brovkin, Victor, Bruhwiler, Lori, Crevoisier, Cyril, Crill, Patrick, Covey, Kristofer, Curry, Charle, Frankenberg, Christian, Gedney, Nicola, Höglund Isaksson, Lena, Ishizawa, Misa, Ito, Akihiko, Joos, Fortunat, Kim Heon, Sook, Kleinen, Thoma, Krummel, Paul, Lamarque Jean, Françoi, Langenfelds, Ray, Locatelli, Robin, Machida, Toshinobu, Maksyutov, Shamil, McDonald Kyle, C., Marshall, Julia, Melton Joe, R., Morino, Isamu, Naik Vaishali, Oapo, Doherty, Simon, Parmentier Frans Jan, W., Patra Prabir, K., Peng, Changhui, Peng, Shushi, Peters Glen, P., Pison, Isabelle, Prigent, Catherine, Prinn, Ronald, Ramonet, Michel, Riley William, J., Saito, Makoto, Santini, Monia, Schroeder, Ronny, Simpson Isobel, J., Spahni, Renato, Steele, Paul, Takizawa, Atsushi, Thornton Brett, F., Tian, Hanqin, Tohjima, Yasunori, Viovy, Nicola, Voulgarakis, Apostolo, van Weele, Michiel, van der Werf Guido, R., Weiss, Ray, Wiedinmyer, Christine, Wilton David, J., Wiltshire, Andy, Worthy, Doug, Wunch, Debra, Xu, Xiyan, Yoshida, Yukio, Zhang, Bowen, Zhang, Zhen, Zhu, Qiuan, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), ICOS-ATC (ICOS-ATC), Istituto Nazionale di Geofisica e Vulcanologia, The Department of Thematic Studies - Water and Environmental Studies, Linköping University (LIU), SRON Netherlands Institute for Space Research (SRON), European Commission - Joint Research Centre [Ispra] (JRC), LM, Canadian Centre for Climate Modelling and Analysis (CCCma), Environment and Climate Change Canada, Department of Animal and Plant Sciences, University of Sheffield [Sheffield], JRC Institute for Environment and Sustainability (IES), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Tropospheric sounding, assimilation, and modeling group [JPL], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH)-NASA-California Institute of Technology (CALTECH), National Institute for Environmental Studies (NIES), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Atmospheric Chemistry Division [Boulder], National Center for Atmospheric Research [Boulder] (NCAR), Oceans and Atmosphere, CSIRO, Strathom Energie, Centre Européen de Réalité Virtuelle (CERV), École Nationale d'Ingénieurs de Brest (ENIB), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Université du Québec à Trois-Rivières (UQTR), ICOS-RAMCES (ICOS-RAMCES), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Shandong Agricultural University (SDAU), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Department of Physics [Imperial College London], Imperial College London, Royal Netherlands Meteorological Institute (KNMI), Faculty of Earth and Life Sciences [Amsterdam] (FALW), Vrije Universiteit Amsterdam [Amsterdam] (VU), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Climate Research Division [Toronto], California Institute of Technology (CALTECH), Laboratoire de Physique et d'Etude des Matériaux (UMR 8213) (LPEM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), USC Viterbi School of Engineering, University of Southern California (USC), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universität Bern [Bern]-Universität Bern [Bern], Scripps Institution of Oceanography (SIO), and University of California-University of California

Subjects
010504 meteorology & atmospheric sciences, Naturgeografi, TRACE GASES, 010501 environmental sciences, Atmospheric sciences, 7. Clean energy, 01 natural sciences, Physical Geography and Environmental Geoscience, Methane, chemistry.chemical_compound, Natural gas, 11. Sustainability, SDG 13 - Climate Action, Meteorology & Atmospheric Sciences, Geosciences, Multidisciplinary, Greenhouse effect, lcsh:Environmental sciences, ComputingMilieux_MISCELLANEOUS, lcsh:GE1-350, [PHYS]Physics [physics], GREENHOUSE-GAS EMISSIONS, methane, lcsh:QE1-996.5, Geology, PAST 2 DECADES, Carbon project, Atmospheric chemistry, Physical Sciences, hydroxyl, Earth and Related Environmental Sciences, Wetland methane emissions, BIOMASS BURNING EMISSIONS, NATURAL-GAS, PROCESS-BASED MODEL, TROPOSPHERIC METHANE, 530 Physics, methane sources, Climate change, Atmospheric Sciences, ATMOSPHERIC HYDROXYL RADICALS, SDG 14 - Life Below Water, ISOTOPIC COMPOSITION, 550 Earth sciences & geology, 0105 earth and related environmental sciences, global model, Science & Technology, business.industry, Environmental engineering, Geovetenskap och miljövetenskap, 15. Life on land, methane budget, lcsh:Geology, Climate Action, Geochemistry, chemistry, Physical Geography, 13. Climate action, Greenhouse gas, General Earth and Planetary Sciences, Environmental science, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], INTERCOMPARISON PROJECT ACCMIP
Abstract

The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and concentrations of CH4 are continuing to increase, making CH4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH4 sources that overlap geographically, and from the destruction of CH4 by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (similar to biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations). For the 2003-2012 decade, global methane emissions are estimated by top-down inversions at 558 TgCH(4) yr(-1), range 540-568. About 60% of global emissions are anthropogenic (range 50-65 %). Since 2010, the bottom-up global emission inventories have been closer to methane emissions in the most carbon-intensive Representative Concentrations Pathway (RCP8.5) and higher than all other RCP scenarios. Bottom-up approaches suggest larger global emissions (736 TgCH(4) yr(-1), range 596-884) mostly because of larger natural emissions from individual sources such as inland waters, natural wetlands and geological sources. Considering the atmospheric constraints on the top-down budget, it is likely that some of the individual emissions reported by the bottom-up approaches are overestimated, leading to too large global emissions. Latitudinal data from top-down emissions indicate a predominance of tropical emissions (similar to 64% of the global budget, amp;lt;30 degrees N) as compared to mid (similar to 32 %, 30-60 degrees N) and high northern latitudes (similar to 4 %, 60-90 degrees N). Top-down inversions consistently infer lower emissions in China (similar to 58 TgCH(4) yr(-1), range 51-72, -14 %) and higher emissions in Africa (86 TgCH(4) yr(-1), range 73-108, + 19 %) than bottom-up values used as prior estimates. Overall, uncertainties for anthropogenic emissions appear smaller than those from natural sources, and the uncertainties on source categories appear larger for top-down inversions than for bottom-up inventories and models. The most important source of uncertainty on the methane budget is attributable to emissions from wetland and other inland waters. We show that the wetland extent could contribute 30-40% on the estimated range for wetland emissions. Other priorities for improving the methane budget include the following: (i) the development of process-based models for inland-water emissions, (ii) the intensification of methane observations at local scale (flux measurements) to constrain bottom-up land surface models, and at regional scale (surface networks and satellites) to constrain top-down inversions, (iii) improvements in the estimation of atmospheric loss by OH, and (iv) improvements of the transport models integrated in top-down inversions. The data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (http://doi.org/10.3334/CDIAC/GLOBAL_METHANE_BUDGET_2016_V1.1) and the Global Carbon Project. Funding Agencies|Swiss National Science Foundation; NASA [NNX14AF93G, NNX14AO73G]; National Environmental Science Program - Earth Systems and Climate Change Hub; European Commission [283576, 633080]; ESA Climate Change Initiative Greenhouse Gases Phase 2 project; US Department of Energy, BER [DE-AC02-05CH11231]; FAO member countries; Environment Research and Technology Development Fund of the Ministry of the Environment, Japan [2-1502]; ERC [322998]; NERC [NE/J00748X/1]; Swedish Research Council VR; Research Council of Norway [244074]; NSF [1243232, 1243220]; National Science and Engineering Research Council of Canada (NSERC); Chinas QianRen Program; CSIRO Australia; Australian Bureau of Meteorology; Australian Institute of Marine Science; Australian Antarctic Division; NOAA USA; Meteorological Service of Canada; National Aeronautic and Space Administration (NASA) [NAG5-12669, NNX07AE89G, NNX11AF17G, NNX07AE87G, NNX07AF09G, NNX11AF15G, NNX11AF16G]; Department of Energy and Climate Change (DECC, UK) [GA01081]; Commonwealth Scientific and Industrial Research Organization (CSIRO Australia); Bureau of Meteorology (Australia); Joint DECC/Defra Met Office Hadley Centre Climate Programme [GA01101]

Published
2016

12. Contribution of environmental forcings to US runoff changes for the period 1950–2010

Author

Whitney L. Forbes, Joshua B. Fisher, Akihiko Ito, Yutao Wang, Hanqin Tian, Peter E. Thornton, Wenting Fu, Forrest M. Hoffman, Tianbao Zhao, Atul K. Jain, Shih-Chieh Kao, Ben Poulter, Christopher R. Schwalm, Daniel J. Hayes, Mingzhou Jin, Aurélien Ribes, Jiafu Mao, Shilong Piao, Daniel M. Riccuito, Yuanyuan Fang, and Xiaoying Shi

Subjects
geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Land use, Renewable Energy, Sustainability and the Environment, 0208 environmental biotechnology, Simulation modeling, Public Health, Environmental and Occupational Health, Climate change, 02 engineering and technology, Seasonality, medicine.disease, 01 natural sciences, 020801 environmental engineering, Climatology, Spring (hydrology), medicine, Period (geology), Environmental science, Precipitation, Surface runoff, 0105 earth and related environmental sciences, General Environmental Science
Published
2018

13. Measuring the economic effects of sea level rise on shore fishing

Author

Okmyung Bin, John C. Whitehead, Ben Poulter, and Christopher F. Dumas

Subjects
Shore, Global and Planetary Change, geography, geography.geographical_feature_category, Ecology, Fishing, Climate change, Fishery, Recreational fishing, Oceanography, Sea level rise, Environmental science, Economic impact analysis, Empirical relationship, Recreation
Abstract

In this paper we develop estimates of the economic effects of sea level rise on marine recreational shore fishing in North Carolina, USA. The relationship between angler behavior and spatial differences in beach width is estimated using the Marine Recreational Fishing Statistics Survey and geospatial data. We exploit the empirical relationship between beach width and fishing site choice by simulating the effects of sea level rise on angler site choice. We find that reductions in beach width negatively affect the quality and number of fishing trips even as anglers adapt by using piers and bridges. Welfare losses are potentially substantial, ranging up 39% of the total value of marine shore fishing in North Carolina.

Published
2009

14. Multicriteria evaluation of discharge simulation in Dynamic Global Vegetation Models

Author

Mark R. Lomas, Yue Li, Soenke Zaehle, Yi Yin, Stephen Sitch, Samuel Levis, Matthieu Guimberteau, Shilong Piao, Fang Zhao, Zhenzhong Zeng, Philippe Ciais, Anders Ahlström, Xiran Li, Lei Wang, Ning Zeng, Hui Yang, Nicolas Viovy, Pierre Friedlingstein, Ben Poulter, Chris Huntingford, Philippe Peylin, Mengtian Huang, Peter Levy, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University [Beijing], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Stanford EARTH, Stanford University, Centre for Ecology and Hydrology [Wallingford] (CEH), Natural Environment Research Council (NERC), National Center for Atmospheric Research [Boulder] (NCAR), Centre for Ecology and Hydrology (CEH), University of Sheffield [Sheffield], Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Montana State University (MSU), Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, University of Maryland [College Park], University of Maryland System, Chinese Academy of Sciences [Beijing] (CAS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospheric Science, geography, geography.geographical_feature_category, Discharge, Drainage basin, Climate change, Forecast skill, Vegetation, 15. Life on land, Snow, Geophysics, Meteorology and Climatology, 13. Climate action, Space and Planetary Science, Climatology, Middle latitudes, Earth and Planetary Sciences (miscellaneous), Environmental science, Hydrology, Surface runoff, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Abstract

International audience; In this study, we assessed the performance of discharge simulations by coupling the runoff from seven Dynamic Global Vegetation Models (DGVMs; LPJ, ORCHIDEE, Sheffield-DGVM, TRIFFID, LPJ-GUESS, CLM4CN, and OCN) to one river routing model for 16 large river basins. The results show that the seasonal cycle of river discharge is generally modeled well in the low and middle latitudes but not in the high latitudes, where the peak discharge (due to snow and ice melting) is underestimated. For the annual mean discharge, the DGVMs chained with the routing model show an underestimation. Furthermore, the 30 year trend of discharge is also underestimated. For the interannual variability of discharge, a skill score based on overlapping of probability density functions (PDFs) suggests that most models correctly reproduce the observed variability (correlation coefficient higher than 0.5; i.e., models account for 50% of observed interannual variability) except for the Lena, Yenisei, Yukon, and the Congo river basins. In addition, we compared the simulated runoff from different simulations where models were forced with either fixed or varying land use. This suggests that both seasonal and annual mean runoff has been little affected by land use change but that the trend itself of runoff is sensitive to land use change. None of the models when considered individually show significantly better performances than any other and in all basins. This suggests that based on current modeling capability, a regional-weighted average of multimodel ensemble projections might be appropriate to reduce the bias in future projection of global river discharge.

Published
2015

15. Plant functional type classification for earth system models: Results from the European Space Agency's Land Cover Climate Change Initiative

Author

Natasha MacBean, Andrew Hartley, Martin Herold, Richard Betts, Carsten Brockmann, Catherine Ottlé, Céline Lamarche, Iryna Khlystova, Sophie Bontemps, Martin Boettcher, Pierre Defourny, Ben Poulter, Stefan Hagemann, Philippe Peylin, Olivier Arino, Dimitri Lederer, Grit Kirches, Marco Peters, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Montana, Institute of Environmental Physics [Bremen] (IUP), University of Bremen, Earth and Life Institute [Louvain-La-Neuve] (ELI), Université Catholique de Louvain = Catholic University of Louvain (UCL), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Modélisation des Surfaces et Interfaces Continentales (MOSAIC), International Center for Tropical Agriculture, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Cover (telecommunications), Meteorology, 010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, Climate change, Land cover, 02 engineering and technology, 01 natural sciences, phenology, Laboratory of Geo-information Science and Remote Sensing, Laboratorium voor Geo-informatiekunde en Remote Sensing, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, database, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, forests, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, business.industry, cycle, Environmental resource management, lcsh:QE1-996.5, resolution, Vegetation, Plant functional type, 15. Life on land, PE&RC, uncertainties, world map, Earth system science, lcsh:Geology, global vegetation model, Thematic map, 13. Climate action, Environmental science, business, ecosystems, World map, feedbacks
Abstract

Global land cover is a key variable in the earth system with feedbacks on climate, biodiversity and natural resources. However, global land cover data sets presently fall short of user needs in providing detailed spatial and thematic information that is consistently mapped over time and easily transferable to the requirements of earth system models. In 2009, the European Space Agency launched the Climate Change Initiative (CCI), with land cover (LC_CCI) as 1 of 13 essential climate variables targeted for research development. The LC_CCI was implemented in three phases: first responding to a survey of user needs; developing a global, moderate-resolution land cover data set for three time periods, or epochs (2000, 2005, and 2010); and the last phase resulting in a user tool for converting land cover to plant functional type equivalents. Here we present the results of the LC_CCI project with a focus on the mapping approach used to convert the United Nations Land Cover Classification System to plant functional types (PFTs). The translation was performed as part of consultative process among map producers and users, and resulted in an open-source conversion tool. A comparison with existing PFT maps used by three earth system modeling teams shows significant differences between the LC_CCI PFT data set and those currently used in earth system models with likely consequences for modeling terrestrial biogeochemistry and land–atmosphere interactions. The main difference between the new LC_CCI product and PFT data sets used currently by three different dynamic global vegetation modeling teams is a reduction in high-latitude grassland cover, a reduction in tropical tree cover and an expansion in temperate forest cover in Europe. The LC_CCI tool is flexible for users to modify land cover to PFT conversions and will evolve as phase 2 of the European Space Agency CCI program continues.

Published
2015

16. Inter-annual variability of carbon and water fluxes in Amazonian forest, Cerrado and pasture sites, as simulated by terrestrial biosphere models

Author

Gonzalo Miguez-Macho, Luis Gustavo Gonçalves de Gonçalves, Kevin Schaefer, Antonio O. Manzi, Natalia Restrepo-Coupe, Bart van den Hurk, David W. Galbraith, Bruno Paraluppi Cestaro, Xiaodan Guan, Philippe Ciais, Joshua B. Fisher, Hans Verbeeck, Marcos Heil Costa, Hewlley Maria Acioli Imbuzeiro, Marcelo Zeri, Michel Nobre Muza, M. Alaf Arain, A. K. Sahoo, Zong-Liang Yang, Alessandro Araújo, Scott R. Saleska, Mingjie Shi, Ian Baker, Bradley O. Christoffersen, Kazuhito Ichii, Naomi M. Levine, Atul K. Jain, Humberto Ribeiro da Rocha, Débora Regina Roberti, Hanqin Tian, Ben Poulter, Celso von Randow, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, Atmospheric Science, 010504 meteorology & atmospheric sciences, Eddy covariance, Climate change, Rainforest, 010603 evolutionary biology, 01 natural sciences, Pasture, Evapotranspiration, Meteorology & Atmospheric Sciences, Precipitation, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, AMAZÔNIA, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, geography, geography.geographical_feature_category, Biosphere, Forestry, Ecotone, 15. Life on land, 13. Climate action, Climatology, Environmental science, Agronomy and Crop Science
Abstract

This study analyzes the inter-annual variability (IAV) of simulations of 21 different land surface model formulations, driven by meteorological conditions measured at 8 flux towers, located in rain forest, forest-savanna ecotone and pasture sites in Amazonia, and one in savanna site in Southeastern Brazil. Annual totals of net ecosystem exchange (NEE) of carbon and evapotranspiration (ET), measured and simulated by each model for each site-year, were compared in terms of year-to-year variability and possible relation to climate drivers. Results have shown that most of models simulations for annual totals of NEE and ET, and IAV of these fluxes, are frequently different from measurements. The average of the model simulations of annual fluxes tend to respond to climatic drivers similarly to the observations, but with noticeable discrepancies. Annual measurements of NEE are negatively correlated to annual rainfall in the forest sites group. Although the ensemble of all models yields a similar result, only three model formulations reproduce a significant negative correlation of simulated NEE with rainfall. For the IAV of ET, tower measurements are controlled by annual variations of radiation and this feature is captured by the ensemble of the models, both at individual sites and when all forest sites are grouped. However, simulated ET values are also significantly correlated to the amount of precipitation in many models and in the model ensemble, while there is no significant correlation in the observations. In general, the surface models are able to reproduce the responses of fluxes to climatic drivers, but improvements are still needed to better capture their inter-annual variability. © 2013 Elsevier B.V..

Published
2013

17. Evaluation of terrestrial carbon cycle models for their response to climate variability and to CO$_2$ trends

Author

Tao Wang, Josep G. Canadell, Peter Levy, Yuecun Ma, Philippe Ciais, Stephen Sitch, Ranga B. Myneni, Nicolas Viovy, Samuel Levis, Alessandro Anav, Soenke Zaehle, Shilong Piao, Xuhui Wang, Xin Lin, Pierre Friedlingstein, Meng Lu, Chris Huntingford, Philippe Peylin, Ning Zeng, Nan Cong, Mark R. Lomas, Junsheng Li, Yiqi Luo, Zhenzhong Sun, Anders Ahlström, Martin Jung, Ben Poulter, Chinese Academy of Sciences [Beijing] (CAS), University of Exeter, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Global Carbon Project (GCP), CSIRO Marine and Atmospheric Research (CSIRO-MAR), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO)-Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Centre for Ecology and Hydrology [Wallingford] (CEH), Natural Environment Research Council (NERC), Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, UK Centre for Ecology & Hydrology, State Key Laboratory of Environmental Criteria and Risk Assessment [Beijing], Chinese Research Academy of Environmental Sciences, Department of Animal and Plant Sciences [Sheffield], University of Sheffield [Sheffield], Institute of Biodiversity Science at Fudan University [Shanghai] (IBSFU), University of Oklahoma (OU), Boston University [Boston] (BU), Department of Atmospheric and Oceanic Science [College Park] (AOSC), University of Maryland [College Park], University of Maryland System-University of Maryland System, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Temperature sensitivity, 010504 meteorology & atmospheric sciences, Climate Change, Biome, Climate change, 010501 environmental sciences, Poaceae, 01 natural sciences, Ecology and Environment, Carbon cycle, Carbon Cycle, Atmospheric Sciences, Meteorology and Climatology, IPCC Fifth Assessment Report, Environmental Chemistry, Ecosystem, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Primary productivity, 0105 earth and related environmental sciences, General Environmental Science, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Ecology, Botany, Biosphere, 15. Life on land, Carbon Dioxide, Models, Theoretical, Phylogeography, 13. Climate action, Climatology, Environmental science, Hydrology, Zoology
Abstract

International audience; The purpose of this study was to evaluate 10 process‐based terrestrial biosphere models that were used for the IPCC fifth Assessment Report. The simulated gross primary productivity (GPP) is compared with flux‐tower‐based estimates by Jung et al. [Journal of Geophysical Research 116 (2011) G00J07] (JU11). The net primary productivity (NPP) apparent sensitivity to climate variability and atmospheric CO2 trends is diagnosed from each model output, using statistical functions. The temperature sensitivity is compared against ecosystem field warming experiments results. The CO2 sensitivity of NPP is compared to the results from four Free‐Air CO2 Enrichment (FACE) experiments. The simulated global net biome productivity (NBP) is compared with the residual land sink (RLS) of the global carbon budget from Friedlingstein et al. [Nature Geoscience 3 (2010) 811] (FR10). We found that models produce a higher GPP (133 ± 15 Pg C yr−1) than JU11 (118 ± 6 Pg C yr−1). In response to rising atmospheric CO2 concentration, modeled NPP increases on average by 16% (5–20%) per 100 ppm, a slightly larger apparent sensitivity of NPP to CO2 than that measured at the FACE experiment locations (13% per 100 ppm). Global NBP differs markedly among individual models, although the mean value of 2.0 ± 0.8 Pg C yr−1 is remarkably close to the mean value of RLS (2.1 ± 1.2 Pg C yr−1). The interannual variability in modeled NBP is significantly correlated with that of RLS for the period 1980–2009. Both model‐to‐model and interannual variation in model GPP is larger than that in model NBP due to the strong coupling causing a positive correlation between ecosystem respiration and GPP in the model. The average linear regression slope of global NBP vs. temperature across the 10 models is −3.0 ± 1.5 Pg C yr−1 °C−1, within the uncertainty of what derived from RLS (−3.9 ± 1.1 Pg C yr−1 °C−1). However, 9 of 10 models overestimate the regression slope of NBP vs. precipitation, compared with the slope of the observed RLS vs. precipitation. With most models lacking processes that control GPP and NBP in addition to CO2 and climate, the agreement between modeled and observation‐based GPP and NBP can be fortuitous. Carbon–nitrogen interactions (only separable in one model) significantly influence the simulated response of carbon cycle to temperature and atmospheric CO2 concentration, suggesting that nutrients limitations should be included in the next generation of terrestrial biosphere models

Published
2013

18. Improving Our Understanding of Earth System Processes: GREENCYCLES Annual Network and Midterm Review Meeting, Barcelona, Spain, 21-23 March 2007

Author

Nicholas Stephens, Ben Poulter, and Sönke Zaehle

Subjects
Environmental change, media_common.quotation_subject, Biosphere, Climate change, Earth system science, Sustainability, General Earth and Planetary Sciences, Environmental science, Physical geography, Function (engineering), Futures contract, Environmental planning, Global environmental analysis, media_common
Abstract

The latest Intergovernmental Panel on Climate Change report documents numerous examples of how human activities are profoundly affecting our global environment with long-term consequences for the climate system. However, considerable uncertainty remains concerning future Earth system responses and likely impacts on the sustainability of life on Earth under the threat of changing climate. The International Geosphere-Biosphere Programme recognizes that understanding and quantifying the complex interactions between the biosphere and the climate system are essential for assessing potential sustainable futures. Major limits to our current understanding of biosphere-climate feedbacks result from (1) a lack of observations on biosphere-atmosphere fluxes of important radiatively active gases and aerosols; (2) insufficient mechanistic understanding of the processes driving these exchanges over different temporal and spatial scales; (3) a lack of Earth system models adequately constrained to predict these exchanges as a function of environmental change; and (4) a lack of integration between scientific disciplines and research centers.

Published
2007

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