Rapport sur la vulnérabilité de la Wallonie au changement climatique

In order to assess climate risks to the main crop production in Wallonia (crops and grasslands), the STICS crop model and a grassland model (GrasSim) were used. Standard crop management techniques were developed for the main Walloon crops (wheat, rapeseed, potatoes, beetroot, maize) and for grassland.

The models were interfaced with soil databases covering the whole of Wallonia. Climate projections corresponding to historical conditions and different projection scenarios were used to characterise the effects of climate change on agricultural production.

Changes in production levels for different crops compared to the historical period depend heavily on the crop, the level of global warming (+2°C, +3°C and +4°C) and the climate model used (CMCC, MIROC or MPI). Below +2°C, the majority of simulated crops predict a drop in production levels compared to the reference period. This implies that, in the short term, agricultural production is likely to decline. However, under global warming of +3 and +4°C, crop models predict an increase in yield levels. This increase is explained, in part, by the fertilising effect of CO₂ (improved photosynthetic efficiency).

However, the stability of yields between years is likely to be significantly affected by global warming. Much greater yield variability is generally observed, meaning that yields could be (much) better or very poor (or even zero). Furthermore, the response within Wallonia is not the same across different agricultural regions. The Jurassic region seems, as a general rule, to be the most negatively affected.

How to cite the report

Lacroix, C., Bindelle, J., Harchies, M., Dumont, B. (2025). Risques climatiques en Wallonie. Indicateurs de rendements des grandes cultures face aux changements climatiques. Service Public de Wallonie (SPW) - Agence Wallonne de l’Air et du Climat (AWAC).

Link to the methodological report:

https://rapport-methodo.s3.eu-west-1.amazonaws.com/Rapport+me%CC%81thodo+-+04.A+-+Agriculture+-+Rendement+des+cultures.pdf

Link to the interactive maps

https://portailclimat-awac.be/indicateurs?location=R%C3%A9gion%20Wallonne&theme=agricultureRendement