Update of the Köppen–Geiger climate classification for EFSA PLH risk assessment

TL;DR

This paper updates the climate classification used by EFSA for plant health risk assessments to a more accurate and recent version.

Contribution

The paper introduces the adoption of the Beck et al. climate classification for improved EU plant health risk assessments.

Findings

The Beck et al. classification provides improved accuracy in regions with complex topography and climate gradients.

Adopting the Beck et al. version results in notable shifts in climate zone boundaries in Europe.

The updated classification enhances the scientific consistency of early-stage plant health risk assessments.

Abstract

The Köppen–Geiger climate classification is widely used for characterising global climatic conditions. At EFSA, in the context of Plant Health Risk Assessment, the Köppen–Geiger system is used as a preliminary step to delineate zones of potential pest establishment across EU territories, providing a first screening prior to more detailed analyses. The version currently used by EFSA is the one by Kottek et al. rescaled after Rubel et al. which is now nearly one decade old. Since its publication, several refined and improved Köppen–Geiger datasets were made available, incorporating broader climate datasets, finer spatial resolutions and updated methodologies for climate variables interpolation. Among these, the recent Beck et al. version provides a globally consistent dataset based on the latest observation‐based gridded climate products and satellite‐derived data, offering improved accuracy particularly in regions with heterogeneous topography and significant climatic gradients. This report highlights the main differences between the version by Kottek et al. and Rubel et al. and the Beck et al. version, with a focus on their relevance for EU plant health risk assessment. The transition to Beck et al. results in notable shifts in classification boundaries within Europe, including adjustments in the extent of temperate, continental and Mediterranean climate zones. These changes are particularly relevant for forecasting the potential distribution of plant pests whose establishment is constrained by specific climatic thresholds. EFSA will therefore be adopting the climate classification developed by Beck et al. enhancing the scientific consistency of its early stage risk assessments, ensuring alignment with the most current and robust climate data available.

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