Impact of Annual Land-Cover Changes on Recent Decades of European climate

The OptFor-EU project investigates the influence of forests on climate and explores Land use and Forest Ecosystem Services practices to support climate change mitigation. To achieve this, regional climate model simulations with RegCMv5 and REMO2020-iMOVE models were conducted to simulate the European climate over the period 1976-2005, incorporating new land use and land cover change derived from the LUCAS LUC dataset (Hoffmann et. al. 2023).

The primary objective presented here is to analyse the role and contribution of land-use (LU) changes along recent decades to the actual transient climate at European scale. According to experiment setup of the CORDEX Flagship Pilot Study LUCAS phase 2, two distinct sets of simulations were conducted: (1) "Dynamical" (D) runs, utilizing yearly varying land-cover data from 1976-2005 to capture the impact of dynamic land-cover changes; and (2) "Static" (S) runs, employing fixed land-cover data from the year 2015 to provide a baseline for comparison. ERA5 reanalysis data served as the lateral boundary conditions for atmospheric forcing in both sets of simulations.

Our results show that although the yearly mean, continental average contribution is small, at seasonal and regional scales the impact can be significant and should be considered as a source contribution to the changing climate trends. Furthermore, we demonstrate that anomaly trends induced by annual regional LU changes trigger large-scale circulation changes at the European level, with anomaly patterns in seasonal temperature and precipitation in Europe linked to induced, quasi-steady thermal gradient changes.

At the regional-local climate scale, changes involve mainly an albedo- evaporation- roughness balance. We analyze the link between LU change hot spots in Europe and recent changes in the frequency and intensity of heavy precipitation, and the underlying mechanisms.

Moreover, our analysis reveals an acceleration in the differences between the D and S simulations during the third decade of the study period. Involved feedbacks are analyzed as potential contributors to the observed recent faster changes.

Preliminary conclusions suggested by this analysis may point to potential implications of LU changes on climate change mitigation and adaptation.

 

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.