A response to the European Court of Auditors Special Report 33/2018

Land degradation is widespread across the European Union (EU) and refers to the long-term decline in the quality and productivity of land resources due to various factors, including human activities and natural processes. It can be manifested through processes such as soil erosion, a loss of soil fertility, and changes in vegetation cover, among other impacts. The United Nations Convention to Combat Desertification (UNCCD) defines desertification as land degradation that occurs in drylands. Drylands are regions where water availability is limited, defined by a low aridity index (precipitation relative to potential evapotranspiration). Sustained periods of increasingly high temperatures, irregular rainfall distribution and intensity in recent years, together with increased competition for land, remind us of the pressing importance of this problem. In addition, climate change scenarios indicate an increasing vulnerability to aridity across, but not limited to, southern and central Europe. Among the conclusions of the European Court of Auditors (ECA) Special Report 33/2018 was the need to establish a methodology and relevant indicators to assess the extent of land degradation and desertification in the EU. To achieve this goal, the ECA report recommended that the Commission should collate and analyse relevant data on land degradation while building on the existing UNCCD indicator framework for SDG 15.3.1 “proportion of land that is degraded over total land area” (this is also referred as the Strategic Objective 1 in the UNCCD Strategic Framework 2018-2030 ). The outcome of the methodology should be regularly presented in a clear and user-friendly way for public use in the form of interactive maps. The ECA report made no recommendation regarding formal reporting obligations. The proposed methodology consists of an improvement of the baseline assessment provided by the UNCCD SDG 15.3.1 framework through: • better characterisation of land cover change, through a more relevant nomenclature for the EU, increased spatial resolution and a revised transition matrix that assess the impact of change based on biophysical changes in vegetation cover; • an optimised characterisation of land productivity for the EU; • replacement of the changes in soil organic carbon stock indicator with a more comprehensive and representative soil degradation indicator; • application of an aridity threshold to define desertification, as highlighted in the ECA report; • identification of areas vulnerable to desertification based on future scenarios of the Aridity Index. The methodology also foresees that the spatial extent of the soil degradation layer can be updated through periodic data collection and derived assessments through the Soil Monitoring and Resilience Directive (entry into force on 16/12/2025). This document describes the: • key concepts; • current strengths and weaknesses in assessing land and soil heath/degradation • a new methodology to assess land degradation by integrating broader soil health data with adapted land cover and land productivity trends that upgrades the SDG 15.3.1 indicator framework; • the identification of desertification and those areas vulnerable to desertification in the future. A separate document presents the application of the methodology on current pan-EU datasets. As requested by the ECA report, a user-friendly dashboard will be made available through the EUSO to provide access to statistics and interactive maps

SCHILLACI Calogero;  BROOTHAERTS Nils;  YUNTA MEZQUITA Felipe;  PANAGOS Panos;  JONES Arwyn; 

2026-07-07

Publications Office of the European Union

JRC140897

978-92-68-39520-2 (online),   

1831-9424 (online),   

EUR 40710,    OP KJ-01-26-190-EN-N (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC140897,   

10.2760/1452814 (online),