Land-Use Harmonization Project

Land-Use Harmonization Project
Name	Land-Use Harmonization Project
Abbreviation	LUH
Established	2010s
Discipline	Earth system modeling
Collaborators	Intergovernmental Panel on Climate Change, Coupled Model Intercomparison Project, International Institute for Applied Systems Analysis

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Land-Use Harmonization Project

The Land-Use Harmonization Project provides temporally consistent, spatially explicit land-use and land-cover change datasets for use in Earth system models and integrated assessment models. It bridges scenarios produced by the Intergovernmental Panel on Climate Change and models used in the Coupled Model Intercomparison Project and supports analyses by institutions such as the International Institute for Applied Systems Analysis, the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, and the European Commission.

Overview

Initiated during the early 2010s to address inconsistencies between historical land-cover reconstructions and future scenario projections, the project emerged as part of efforts coordinated around the Coupled Model Intercomparison Project Phase 5 and later CMIP6. Key contributors included researchers affiliated with the International Institute for Applied Systems Analysis, the University of Maryland, the Lawrence Livermore National Laboratory, and the National Center for Atmospheric Research. Funders and stakeholders involved agencies such as the European Commission, the National Science Foundation, and the United States Department of Energy, and the datasets were integrated into scenario frameworks used by the Intergovernmental Panel on Climate Change assessments and modeling work for the World Climate Research Programme.

The harmonization approach combines historical land-cover reconstructions from satellite-derived products like those from the Landsat program and the MODIS sensor, national statistics compiled by the Food and Agriculture Organization of the United Nations, and scenario outputs from integrated assessment models developed at institutions including the International Institute for Applied Systems Analysis, IIASA, Potsdam Institute for Climate Impact Research, and teams behind the Global Change Assessment Model and the IMAGE model. Algorithms apply allocation rules and bookkeeping methods influenced by studies at the Lawrence Berkeley National Laboratory and the National Center for Atmospheric Research to produce gridded products compatible with Earth system models operated by groups at the Max Planck Institute for Meteorology, Met Office Hadley Centre, and NASA Goddard Institute for Space Studies.

Researchers use the datasets to drive land-surface, carbon-cycle, and biogeochemical modules in Earth system models used by centers such as the Hadley Centre, the NOAA Geophysical Fluid Dynamics Laboratory, and the NASA Goddard Space Flight Center. Policymakers at the United Nations Framework Convention on Climate Change and analysts at the World Bank and Organisation for Economic Co-operation and Development use outputs to evaluate land-based mitigation pathways associated with Paris Agreement goals and national submissions like Nationally Determined Contributions. Conservation organizations such as World Wildlife Fund and Conservation International apply harmonized land-use scenarios to assess biodiversity impacts referenced in reports by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.

Validation compares harmonized outputs with observational datasets from the Landsat program, the European Space Agency Climate Change Initiative, and national land-use statistics from the Food and Agriculture Organization of the United Nations and United States Geological Survey. Uncertainties stem from differences among integrated assessment models produced by teams at IIASA, the Potsdam Institute, and the International Institute for Applied Systems Analysis, as well as from biases in remote-sensing retrievals from MODIS and algorithmic choices documented in publications by researchers at Lawrence Livermore National Laboratory and University of Maryland. Sensitivity analyses often reference methodologies used in the Coupled Model Intercomparison Project and assessments by the Intergovernmental Panel on Climate Change.

The project operates through collaborations among modeling centers, research institutions, and intergovernmental bodies including the Intergovernmental Panel on Climate Change, the World Climate Research Programme, the International Institute for Applied Systems Analysis, the European Commission, and national agencies like the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration. Data stewardship and distribution involve partnerships with data facilities such as the Earth System Grid Federation and repositories associated with the NASA Earth Exchange and the UK Centre for Environmental Data Analysis.

The harmonized datasets have become standard inputs for scenario-based modeling in assessments by the IPCC and in research at the Max Planck Institute for Meteorology, Potsdam Institute for Climate Impact Research, and University of Oxford, influencing policy dialogue at the United Nations Framework Convention on Climate Change and funding priorities at agencies like the National Science Foundation. Criticisms focus on aggregation choices, resolution limits, and representation of land management practices raised by scholars at Harvard University, Stanford University, and civil society groups such as Greenpeace and Friends of the Earth. Debates continue between proponents at modeling centers like the Met Office Hadley Centre and critics advocating higher-resolution, observation-driven alternatives championed by teams at the European Space Agency and the United States Geological Survey.