Regional Climate Change Effects on the Viticulture in Portugal

The grapevine (Vitis vinifera) is widely cultivated for the production of wine and other commodities. Wine is globally traded, with an annual market value of approximately USD 4 billion in Portugal alone. However, climate change is expected to profoundly alter regional temperature and precipitation regimes across the Iberian Peninsula and, thus, in continental Portugal, potentially threatening to impact viticulture. We used boosted regression trees and environmental variables describing the climate, soil, topography, and irrigation with a large number of presences (N = 7002) to estimate grapevine suitability for a baseline (1981-2010) and three future periods spanning from 2011 to 2100 using two climate trajectories (SSP3-7.0 and SSP5-8.5) and irrigation scenarios (continued and ceased). Under SSP3-7.0 with irrigation and SSP5-8.5 without irrigation, our results suggest a decline in suitable viticulture area across continental Portugal of similar to 20% and similar to 80% by 2041-2070 and 2011-2041, respectively. Following this decline, our data suggest a potential recovery by 2071-2100 of similar to 6% and similar to 186%, respectively. However, regional change is more complex: by 2071-2100, the Regiao Norte, the Douro wine region, and the Algarve, for example, each would experience future changes in suitable area in the range of approximately -92% to -48%, -86% to -24%, and -59% to 267%, respectively, depending mostly on the practicality of irrigation.