Assessing the impact of transient land use and land cover changes in regional climate modeling using the LUCAS LUC dataset with a focus on forest cover changes in Europe

Le résumé fourni par la source

Land use and land cover changes (LULCC), driven by human activities such as urbanization, afforestation or agricultural expansion, alter land surface properties. These alterations can lead to modifications in energy and water fluxes between the land surface and the atmosphere, thereby influencing the local and regional climate. Due to forests’ ability to sequester carbon, climate-resilient forest management is pivotal in climate change adaptation and mitigation, and its effects and feedbacks have to be well understood. However, in regional climate modeling, LULCC is often neglected, and the land cover is represented with a static land use and land cover map. Therefore, the WCRP CORDEX flagship pilot study LUCAS (Land Use and Climate Across Scales) aims to assess the impact of LULCC on regional climate with a coordinated regional climate model ensemble approach. A realistic implementation of LULCC into regional climate models requires consideration of transient LULCC. The LUCAS LUC dataset, developed by Hoffmann et al. (2023) provides these transient LULCC on high resolution suitable for regional climate modeling. The dataset is based on the plant functional type (PFT) distribution derived from the ESA-CCI LC dataset and provides annual LULCC based on the LUH2 dataset until the end of the century for different SSP scenarios and the historical period 1950–2014. As a collaboration between the FPS LUCAS and the EU Horizon project OptFor-EU, we aim to investigate the impact of LULCC, in particular of forest cover changes on the regional climate. Therefore, we implemented the LUCAS LUC dataset in our regional climate model system REMO2020-iMOVE. We use REMO in its hydrostatic configuration and couple it interactively to the mosaic-based vegetation module iMOVE, which represents the PFT distribution with land cover tiles. Our simulations cover Europe on a 12 km horizontal resolution. In the first step, our simulations are driven by the reanalysis data of ERA5.1 from 1979 – 2020, which we evaluate against observational data. In the second step, we conduct simulations driven by the global earth system model MPI-ESM-HR for the historical and the future period until the end of the century, under the SSP126 scenario with corresponding greenhouse gas forcing and LULCC data. By comparing the simulations that employ transient LULCC with those that employ static LULCC maps, we are able to quantify the impact of forest cover changes on regional climate in Europe. Reference Hoffmann, P., Reinhart, V., Rechid, D., de Noblet-Ducoudré, N., Davin, E. L., Asmus, C., Bechtel, B., Böhner, J., Katragkou, E., and Luyssaert, S.: High-resolution land use and land cover dataset for regional climate modelling: historical and future changes in Europe, Earth Syst. Sci. Data, 15, 3819–3852, https://doi.org/10.5194/essd-15-3819-2023, 2023.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.