title: Hotspots of uncertainty in land-use and land-cover change projections: a global-scale model comparison.
abstract: Model-based global projections of future land-use and land-cover (LULC) change are frequently used in environmental assessments to study the impact of LULC change on environmental services and to provide decision support for policy. These projections are characterized by a high uncertainty in terms of quantity and allocation of projected changes, which can severely impact the results of environmental assessments. In this study, we identify hotspots of uncertainty, based on 43 simulations from 11 global-scale LULC change models representing a wide range of assumptions of future biophysical and socioeconomic conditions. We attribute components of uncertainty to input data, model structure, scenario storyline and a residual term, based on a regression analysis and analysis of variance. From this diverse set of models and scenarios, we find that the uncertainty varies, depending on the region and the LULC type under consideration. Hotspots of uncertainty appear mainly at the edges of globally important biomes (e.g., boreal and tropical forests). Our results indicate that an important source of uncertainty in forest and pasture areas originates from different input data applied in the models. Cropland, in contrast, is more consistent among the starting conditions, while variation in the projections gradually increases over time due to diverse scenario assumptions and different modeling approaches. Comparisons at the grid cell level indicate that disagreement is mainly related to LULC type definitions and the individual model allocation schemes. We conclude that improving the quality and consistency of observational data utilized in the modeling process and improving the allocation mechanisms of LULC change models remain important challenges. Current LULC representation in environmental assessments might miss the uncertainty arising from the diversity of LULC change modeling approaches, and many studies ignore the uncertainty in LULC projections in assessments of LULC change impacts on climate, water resources or biodiversity.
authors.affiliation: Environmental Geography Group, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Prestele
authors.affiliation: School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh, EH89XP, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Alexander
authors.affiliation: School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh, EH89XP, UK.
authors.forename: Mark D A
authors.initials: MD
authors.lastname: Rounsevell
authors.affiliation: Department Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology, Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany.
authors.forename: Almut
authors.initials: A
authors.lastname: Arneth
authors.affiliation: Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, 20740, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Calvin
authors.affiliation: PBL Netherlands Environmental Assessment Agency, P.O. Box 303, 3720, AH Bilthoven, The Netherlands.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Doelman
authors.affiliation: Environmental Geography Group, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
authors.forename: David A
authors.initials: DA
authors.lastname: Eitelberg
authors.affiliation: Department of Geography and Ecosystem Science, Lund University, Sölvegatan 12, Lund, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Engström
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimori
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Ecosystem Services and Management Program, International Institute for Applied Systems Analysis, A-2361, Laxenburg, Austria.
authors.forename: Petr
authors.initials: P
authors.lastname: Havlik
authors.affiliation: Potsdam Institute for Climate Impact Research (PIK), P.O. Box 60 12 03, 14412, Potsdam, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Humpenöder
authors.affiliation: Department of Atmospheric Sciences, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Atul K
authors.initials: AK
authors.lastname: Jain
authors.affiliation: Ecosystem Services and Management Program, International Institute for Applied Systems Analysis, A-2361, Laxenburg, Austria.
authors.forename: Tamás
authors.initials: T
authors.lastname: Krisztin
authors.affiliation: Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, 20740, USA.
authors.forename: Page
authors.initials: P
authors.lastname: Kyle
authors.affiliation: Department of Atmospheric Sciences, University of Illinois, Urbana, IL, 61801, USA.
authors.forename: Prasanth
authors.initials: P
authors.lastname: Meiyappan
authors.affiliation: Potsdam Institute for Climate Impact Research (PIK), P.O. Box 60 12 03, 14412, Potsdam, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Popp
authors.affiliation: Resource and Rural Economics Division, Economic Research Service, US Department of Agriculture, Washington, DC, 20250, USA.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Sands
authors.affiliation: Center for Environmental Systems Research, University of Kassel, Wilhelmshöher Allee 47, D-34109, Kassel, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Schaldach
authors.affiliation: Center for Environmental Systems Research, University of Kassel, Wilhelmshöher Allee 47, D-34109, Kassel, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Schüngel
authors.affiliation: PBL Netherlands Environmental Assessment Agency, P.O. Box 303, 3720, AH Bilthoven, The Netherlands.
authors.forename: Elke
authors.initials: E
authors.lastname: Stehfest
authors.affiliation: LEI, Wageningen University and Research Centre, P.O. Box 29703, 2502, LS The Hague, The Netherlands.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Tabeau
authors.affiliation: LEI, Wageningen University and Research Centre, P.O. Box 29703, 2502, LS The Hague, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Van Meijl
authors.affiliation: Environmental Geography Group, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Jasper
authors.initials: J
authors.lastname: Van Vliet
authors.affiliation: Environmental Geography Group, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.|Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Verburg
mesh_terms: D044822:Biodiversity; D003247:Conservation of Natural Resources; D017753:Ecosystem; D008962:Models, Theoretical; D035501:Uncertainty
keywords: land-use allocation; land-use change; land-use model uncertainty; map comparison; model intercomparison; model variation