From Past Exceptional Extremes to Frequent Future Risks: How Climate Change Shapes the Fate of Common Wheat in France

Climate change is reshaping the agroclimatic conditions for wheat, taking some past decennial events to frequent climatic features, substantially increasing the probability of crop stress and yield loss. We propose a method using ecoclimatic indicators combined with probability models, continuous-time regression and copulas, to evaluate — in non-stationary context —the future climate suitability of common wheat in France expressed as the probability of exceeding past decennial thresholds. Under a high-emission scenario, our analysis identifies four emerging risks from 2050 onward: early heat stress and warm nights during the flag-leaf-to-anthesis stage, late warm nights from anthesis to grain maturity, and devernalisation. Precipitation- and humidity-related extremes during the vegetative phase are projected to slightly increase or stagnate, with strong regional and model-specific variability. Mild winters are likely to become a dominant climatic feature by century’s end, while late cold stress events decline sharply. In contrast, reproductive-phase heat stress intensifies markedly, becoming a dominant agroclimatic constraint by century’s end, whereas risks linked to excess moisture or precipitation decrease. Drought-related stress remains mostly stable, due to shorter phenological cycles. By century’s end, under high emission scenario, compound hazards —such as simultaneous drought and heat stress during key reproductive stages—are projected to become 3 to 6 times more frequent than in the historical baseline. Compound mild-winter and wet- or damp-condition events increase 2.5- to 12-fold. Regional disparities emerge: the English Channel coast and the Paris Basin appear comparatively less exposed to these climatic risks, positioning them as potential, though not risk-free, future refuges for wheat cultivation. A low-emission mitigation pathway would reduce the frequency of these risks by a factor of 2 to 6, and reduce interannual risk variability by up to 45% relative to high emissions. These findings highlight priority targets for adaptation and underscore the urgent need for mitigation to safeguard wheat production.