Comparing the influence of net and gross anthropogenic land use and land cover changes on the carbon cycle in the MPI-ESM

Abstract. Global vegetation models traditionally treat anthropogenic land use and land cover changes (LULCC) only as the changes in vegetation cover seen from one year to the next (net transitions). This approach ignores sub-grid-scale processes such as shifting cultivation which do not affect the net vegetation distribution but which have an impact on the carbon budget. The simulations for the Coupled Model Intercomparison Project Phase 5 (CMIP5) all describe LULCC using the Harmonized Land-Use Protocol. Though this protocol describes such sub-grid-scale processes (gross transitions), some of the CMIP5 models still use the traditional approach. Using JSBACH/CBALANCE – the land carbon component of the Max Planck Institute Earth System Model (MPI-ESM), this study demonstrates how this potentially leads to a severe underestimation of the carbon emissions from LULCC. Using net transitions lowers the average land use emissions from 1.44 to 0.90 Pg C yr–1 (38%) during the historical period (1850–2005) – a total lowering by 85 Pg C. The difference between the methods is smaller in the RCP-scenarios (2006–2100) but in RCP2.6 and RCP8.5 still cumulates to 30–40 Pg C (on average 0.3–0.4 Pg C yr–1 or 13–25%). In RCP4.5 essentially no difference between the methods is found. Results from models using net transitions are furthermore found to be sensitive to model resolution.

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Comparing the influence of net and gross anthropogenic land-use and land-cover changes on the carbon cycle in the MPI-ESM

Biogeosciences ◽

10.5194/bg-11-4817-2014 ◽

2014 ◽

Vol 11 (17) ◽

pp. 4817-4828 ◽

Cited By ~ 42

Author(s):

S. Wilkenskjeld ◽

S. Kloster ◽

J. Pongratz ◽

T. Raddatz ◽

C. H. Reick

Keyword(s):

Land Use ◽

Land Cover ◽

Traditional Approach ◽

Cmip5 Models ◽

Historical Period ◽

Land Cover Changes ◽

Subgrid Scale ◽

Max Planck ◽

Rcp Scenarios ◽

Anthropogenic Land Use

Abstract. Global vegetation models traditionally treat anthropogenic land-use and land-cover changes (LULCCs) only as the changes in vegetation cover seen from one year to the next (net transitions). This approach ignores subgrid-scale processes such as shifting cultivation which do not affect the net vegetation distribution but which have an impact on the carbon budget. The differences in the carbon stocks feed back on processes like wildfires and desert formation. The simulations for the Coupled Model Intercomparison Project Phase 5 (CMIP5) all describe LULCCs using the "Land-Use Harmonization Dataset". Though this dataset describes such subgrid-scale processes (gross transitions), some of the CMIP5 models still use the traditional approach. Using JSBACH/CBALANCE – the land carbon component of the Max Planck Institute Earth System Model (MPI-ESM), this study demonstrates how this potentially leads to a severe underestimation of the carbon emissions from LULCCs Using net transitions lowers the average land-use emissions from 1.44 to 0.90 Pg C yr−1 (38%) during the historical period (1850–2005) – a total lowering by 85 Pg C. The difference between the methods is smaller in the RCP scenarios (2006–2100) but in RCP2.6 and RCP8.5 still cumulates to 30–40 Pg C (on average 0.3–0.4 Pg C yr−1 or 13–25%). In RCP4.5 essentially no difference between the methods is found. Results from models using net transitions are furthermore found to be sensitive to model resolution.

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Corrigendum to "Comparing the influence of net and gross anthropogenic land-use and land-cover changes on the carbon cycle in the MPI-ESM" published in Biogeosciences, 11, 4817–4828, 2014

Biogeosciences ◽

10.5194/bg-12-3041-2015 ◽

2015 ◽

Vol 12 (10) ◽

pp. 3041-3041

Author(s):

S. Wilkenskjeld ◽

S. Kloster ◽

J. Pongratz ◽

T. Raddatz ◽

C. H. Reick

Keyword(s):

Land Use ◽

Land Cover ◽

Carbon Cycle ◽

Land Cover Changes ◽

Anthropogenic Land Use

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Do we need to include anthropogenic land-use and land-cover changes in paleoclimate simulations?

Past Global Change Magazine ◽

10.22498/pages.26.1.4 ◽

2018 ◽

Vol 26 (1) ◽

pp. 4-5 ◽

Cited By ~ 4

Author(s):

Sandy P Harrison ◽

BD Stocker ◽

K Klein Goldewijk ◽

JO Kaplan ◽

P Braconnot

Keyword(s):

Land Use ◽

Land Cover ◽

Land Cover Changes ◽

Anthropogenic Land Use

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Biases in the albedo sensitivity to deforestation in CMIP5 models and their impacts on the associated historical Radiative Forcing

10.5194/esd-2019-94 ◽

2020 ◽

Cited By ~ 2

Author(s):

Quentin Lejeune ◽

Edouard L. Davin ◽

Grégory Duveiller ◽

Bas Crezee ◽

Ronny Meier ◽

...

Keyword(s):

Land Cover ◽

Radiative Forcing ◽

Climate Model ◽

Coupled Model ◽

Climate Impact ◽

Cmip5 Models ◽

Land Cover Changes ◽

Model Simulations ◽

Land Cover Types ◽

Conversion Rates

Abstract. Climate model biases in the representation of albedo variations between land cover types contribute to uncertainties on the climate impact of land cover changes since pre-industrial times, and especially on the associated Radiative Forcing. The recent publications of new observation-based datasets offer opportunities to investigate these biases and their impact on historical albedo changes in simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Conducting such an assessment is however complicated by the non-availability of albedo values for specific land cover types, as well as the limited number of simulations isolating the land use forcing in CMIP. In this study, we demonstrate the suitability of a new methodology to extract the albedo of trees and crops/grasses in standard climate model simulations. We then apply it to historical runs from 13 CMIP5 models and compare the obtained results to satellite-derived reference data. This allows us to identify substantial biases in the representation of the albedo of trees, crops/grasses, and the albedo change due to the transition between these two land cover types in the analysed models. Additionally, we reconstruct the local albedo changes induced by historical conversions between trees and crops/grasses for 15 CMIP5 models. This allows us to derive estimates of the Radiative Forcing from land cover changes since pre-industrial times ranging between 0 and −0.22 W/m2, with a mean value of −0.07 W/m2. Constraining the albedo response to transitions between trees and crops/grasses from the models with satellite-derived data leads to an increase in this range, however after excluding two models with unrealistic conversion rates from trees to crops/grasses we obtain a revised model mean estimate of −0.11 W/m2 (with individual model results between −0.04 and −0.16 W/m2). These numbers are at the lower end of the range provided by the IPCC AR5 (−0.15 ± 0.10 W/m2). The approach described in this study can be applied on other model simulations, such as those from CMIP6, especially as a diagnostic enabling the reproduction of the model evaluation part has been included in the ESMValTool v2.0.

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Biases in the albedo sensitivity to deforestation in CMIP5 models and their impacts on the associated historical radiative forcing

Earth System Dynamics ◽

10.5194/esd-11-1209-2020 ◽

2020 ◽

Vol 11 (4) ◽

pp. 1209-1232

Author(s):

Quentin Lejeune ◽

Edouard L. Davin ◽

Grégory Duveiller ◽

Bas Crezee ◽

Ronny Meier ◽

...

Keyword(s):

Land Cover ◽

Radiative Forcing ◽

Surface Albedo ◽

Climate Model ◽

Coupled Model ◽

Climate Impact ◽

Cmip5 Models ◽

Land Cover Changes ◽

Model Simulations ◽

Conversion Rates

Abstract. Climate model biases in the representation of albedo variations between land cover classes contribute to uncertainties on the climate impact of land cover changes since pre-industrial times, especially on the associated radiative forcing. Recent publications of new observation-based datasets offer opportunities to investigate these biases and their impact on historical surface albedo changes in simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Conducting such an assessment is, however, complicated by the non-availability of albedo values for specific land cover classes in CMIP and the limited number of simulations isolating the land use forcing. In this study, we demonstrate the suitability of a new methodology to extract the albedo of trees and crops–grasses in standard climate model simulations. We then apply it to historical runs from 17 CMIP5 models and compare the obtained results to satellite-derived reference data. This allows us to identify substantial biases in the representation of the albedo of trees and crops–grasses as well as the surface albedo change due to the transition between these two land cover classes in the analysed models. Additionally, we reconstruct the local surface albedo changes induced by historical conversions between trees and crops–grasses for 15 CMIP5 models. This allows us to derive estimates of the albedo-induced radiative forcing from land cover changes since pre-industrial times. We find a multi-model range from 0 to −0.17 W m−2, with a mean value of −0.07 W m−2. Constraining the surface albedo response to transitions between trees and crops–grasses from the models with satellite-derived data leads to a revised multi-model mean estimate of −0.09 W m−2 but an increase in the multi-model range. However, after excluding one model with unrealistic conversion rates from trees to crops–grasses the remaining individual model results vary between −0.03 and −0.11 W m−2. These numbers are at the lower end of the range provided by the IPCC AR5 (-0.15±0.10 W m−2). The approach described in this study can be applied to other model simulations, such as those from CMIP6, especially as the evaluation diagnostic described here has been included in the ESMValTool v2.0.

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