Weather potential for high-quality still wine from Chardonnay viticulture in different regions of the UK with climate change

UK viticulture is benefitting from climate change with an increase in vineyard area and a move towards French grapevine varieties, primarily Chardonnay and Pinot noir, to produce sparkling wine. Doubt remains, however, as to how good UK still wine can be from these varieties. The simple Chablis vintage model uses only three climatic indices: mean temperature from April to September, mean minimum temperature in September (cool night index) and total rainfall from June to September. It was applied to the UK for the periods 1981–2000, 2010–2019 and, with climate change projections, to 2040–2059 to locate sites in the UK with the climate potential to produce high-quality Chardonnay still wine. Weather data for 1981–2000 and 2010–2019 were taken from the Met Office’s HadUK-Grid at a resolution of 5 × 5 km, and climate projections for 2040–2059 were derived from UKCP18, using intermediate emission scenario RCP 4.5 at the 5th, 50th and 95th percentile probabilities. Recent and current climatic conditions throughout most of the UK were unsuitable for sustainable production of high-quality still Chardonnay wine (only 0.2 to 1.8 % of UK land area suitable), but model scores corresponded with high-quality Chardonnay still wine production observed in some regions of England in 2018. Under the 5th percentile RCP 4.5 projection for 2040–2059, climatic conditions are similar to 2010–2019 and generally unsuitable for sustainable, high-quality still Chardonnay wine production. Under the median and 95th percentile projections for 2040–2059, however, South East England and East of England have the potential for high-quality still Chardonnay wine production in an average year, and Central England also with the 95th percentile projection. Overall, climate change is expected to benefit the production of high-quality still Chardonnay wine in the medium term, with up to 42.4 % of UK land possibly climatically (but not necessarily agronomically) suitable by mid-century. The model does not account for extreme events, however, and there is uncertainty over future inter-annual weather variability, and so the sustainability of high-quality still wine production. Planting Chardonnay clones suitable for both sparkling and still wines in the most-suitable areas of England would provide flexibility and so resilience.