Shared socioeconomic pathways of key viticultural indicators in the Douro Region

Abstract

Climate change is poised to substantially alter viticulture in traditional wine regions, including the Douro winemaking region (DWR) of northern Portugal. This study assesses projected impacts on grapevine yield, phenology, and potential alcohol content using an ensemble of high-resolution downscaled climate simulations for the recent past (1986–2015) and mid-century (2041–2070) under two emission pathways: SSP1–2.6 and SSP5–8.5. Results show a consistent and robust signal of change across all indicators, with greater magnitude and variability under SSP5–8.5. Yield is projected to decline widely across the region (−1 to −3 t/ha), particularly in high-productivity zones such as Douro Superior, highlighting substantial spatial heterogeneity and increased vulnerability. Phenology is expected to advance markedly, with flowering occurring up to 30 days earlier, especially under the high-emissions scenario, potentially affecting berry development, amplifying frost risk, and challenging established vineyard management practices. Potential alcohol content is also projected to rise across the DWR, exceeding +2% vol in some areas under SSP5–8.5, posing risks to wine typicity, regulatory classifications, and Denomination of Origin boundaries, and requiring both viticultural and oenological adjustments. Overall, the findings indicate significant, spatially variable climate-driven shifts in Douro viticulture. While impacts may be moderated under SSP1–2.6, the stronger changes projected under SSP5–8.5 underscore the need for timely adaptation to safeguard wine quality, socioeconomic resilience, and regional identity.