Erosion in Europe - Projections by 2050
Projections of soil loss by water erosion in Europe by 2050
Soil loss by water erosion is projected to increase by 13–22.5% in the EU and UK by 2050, mainly due to increased rainfall intensity. This soil loss is expected to be greatest in central and northern Europe, which could see losses of up to 100% in some areas. Soil erosion in southern Europe is projected to be largely unchanged due to a decline in precipitation patterns.We used the Revised Universal Soil Loss Equation (RUSLE) adjusted at continental scale with projections of future rainfall erosivity and land use change. Future rainfall erosivity is predicted using an average composite of 19 Global Climate Models (GCMs) from the Coupled Model Inter-comparison Projects (CMIP5) WorldClim dataset across three Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5). Concerning future land use change and crop dynamics, we used the projections provided by the Common Agricultural Policy Regional Impact Analysis (CAPRI) model.
- Modelled area: 1.8 million Km2 which is about ~41.5% of European Union (EU27) and UK (focus in agricultural soils).
- Resolution: 100mx 100m
- Global Coverage: European Union (EU27) and UK
- Climate inpiuts: Three alternative (2.6, 4.5 & 8.5) Shared Socioeconomic Pathway and Representative Concentration Pathway (SSP-RCP) scenarios. 19 General Climate Circulation Models (GCMs) used to assess future rainfall erosivity scenarios
- Land cover inputs: Common Agricultural Policy Regional Impact analysis (CAPRI) model projects on crop dynamics and land use changes.
- Total soil loss:The baseline model (2016) estimates the soil loss in agricultural soils to about 553 Mt yr-1 while the projections estimate an increase to 595-645 Mt yr-1 by 2050.
- Mean soil loss: Soil loss by water erosion is projected to increase by 13–22.5 % in EU and UK by 2050. In the baseline year (2016), mean soil loss is about 3.07 t ha-1 yr-1 in EU agricultural soils. Under the business-as-usual or least mitigation pathway scenario (RCP8.5), this is expected to increase to 3.76t ha-1 yr-1 by 2050.
Changes in future soil erosion rates are driven by climatic conditions, land use patterns, socio-economic development, farmers’ choices, and importantly modified by agro-environmental policies. This study simulates the impact of expected climatic and land use change projections on future rates of soil erosion by water (sheet and rill processes) in 2050 within the agricultural areas of the European Union and the UK, compared to a current representative baseline (2016). We used the Revised Universal Soil Loss Equation (RUSLE) adjusted at continental scale with projections of future rainfall erosivity and land use change. Future rainfall erosivity is predicted using an average composite of 19 Global Climate Models (GCMs) from the Coupled Model Inter-comparison Projects (CMIP5) WorldClim dataset across three Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5). Concerning future land use change and crop dynamics, we used the projections provided by the Common Agricultural Policy Regional Impact Analysis (CAPRI) model.
Depending on the RCP scenario, we estimate a +13%-22.5% increase in the mean soil erosion rate in the EU and UK, rising from an estimated 3.07 t ha-1 yr-1 (2016) to between 3.46 t ha-1 yr-1 (RCP2.6 scenario) and 3.76 t ha-1 yr-1 (RCP8.5 scenario). Here, we disentangle the impact of land use change and climate change in relation to future soil losses. Projected land use change in the EU and UK indicates an overall increase of pasture coverage in place of croplands. This land use change is estimated to reduce soil erosion rates (-3%). In contrast, the increases in future rainfall erosivity (+15.7%-25.5%) will force important increases of soil erosion requiring further targeted intervention measures.
Given that agro-environmental policies will be the most effective mechanisms to offset this future increase in soil erosion rates, this study proposes soil conservation instruments foreseen in the EU Common Agricultural Policy (CAP) to run policy scenarios. A targeted application of cover crops in soil erosion hotspots combined with limited soil disturbance measures can partially or completely mitigate the effect of climate change on soil losses. Effective mitigation of future soil losses requires policy measures for soil conservation on at least 50% of agricultural land with erosion rates above 5 t ha-1 yr-1.
Compared to land use change, climate change showed a dominant effect on future soil erosion projections. To ensure comprehensiveness, we have considered climate projections for the year 2050 from 19 models applied in the EU plus the UK for three different RCP scenarios. Although the RCP2.6 and RCP4.5 climate change scenarios could result in similar mean values for the entire study area, we found consequentially different spatial variations in the patterns of soil loss (between 2016 and 2050). The less aggressive mitigation pathway RCP8.5 climate change scenario is alarming as it will aggravate soil loss in 84% of the study area and increase the soil loss rates by at least 45% in Western Europe. The Mediterranean basin shows smaller increases mainly due to the mixed impact of climate change on rainfall erosivity in this region.
The future projections of soil loss rates could be at least 3% higher if land use changes were ignored. In this study, the main drivers of land use change between 2016 and 2050 were crop composition dynamics, the transformation of cropland to grasslands and the shrinkage of EU agricultural area by 3.9%. Therefore, it is recommended that projections of soil losses due to water erosion should consider both a wide range of climate change scenarios but also future land use changes.
As agro-environmental policies are the only mechanism to mitigate the future negative trend of soil loss in the EU, we performed a policy relevant scenario analysis. Among the scenarios, we included the uptake of management practices relevant to green soil coverage and minimum soil disturbance and have some quotations in the future Common Agricultural Policy (post-2020 CAP). The most effective policy instrument is to link CAP incentives to environmental performance in a targeted way. However, the application of soil conservation measures such as cover crops and reduced tillage should include at least 50% of the hotspots (i.e., where soil losses exceed 5 t ha-1 yr-1) to neutralize the future impact of climate change on water erosion. The post 2020 Common Agricultural Policy and other EU policy developments (EU Green Deal) may include a stronger soil conservation package with quantitative targets to mitigate the important soil erosion increase which is expected due to climate change in Europe.
Data and additional material
Panagos, P., Ballabio, C., Himics, M., Scarpa, S., Matthews, F., Bogonos, M., Poesen, J., Borrelli, P., 2021. Projections of soil loss by water erosion in Europe by 2050. Environmental Science & Policy, 124: 380-392.
Fig.1: Summary of main indicators for soil loss by water erosion in agricultural soils of the EU by 2050.
Fig.2: Regional differences between the baseline and the future soil loss projections
Fig.3: Model integration for estimating the erosion projections 2050.