A climate for sustainable wine production : modelling the effects of weather variability and climate change on viticulture in England and Wales

• Main Author: Nesbitt, Alistair
• Published: University of East Anglia 2016
• Subjects: 634.8
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.705140

The spatial distribution of commercial viticulture is within narrow climatic niches characterised by growing season average temperatures of 13–21oC and meteorological structures conducive to Vitis vinifera L. grape maturation and sustainable grape yields. Climate change may significantly threaten viticulture in some established regions if in-situ adaptation is unviable or undesirable; it may also present opportunities elsewhere. This thesis explores past, present and future weather and climate risks in the emerging cool-climate viticulture regions of England and Wales. A recent (2004–2013) significant expansion (148%) in viticulture area and a shift to Chardonnay and Pinot noir cultivation for sparkling wine production has been accompanied by international recognition of high quality English wine. Warming growing seasons have been touted as the key growth enabler, however the geographic positioning of England and Wales exposes viticulture to threats from inter-annual weather variability. This first quantitative and qualitative analysis of viticulture climate suitability in England and Wales considers grape-growers perspectives’ on climate change and weather variability, complemented by an analysis of climate and weather data and their recent relationships with wine yields and sector growth. Employing spatial modelling tools and fuzzy logic this thesis also establishes the first mesoscale assessment of land suitability for viticulture in England and Wales. Furthermore, this study examines potential for agro-economic diversification and presents projected future (2021–2040 and 2041–2060) climate change impacts on wine production and quality in south-east England and the Champagne region of France. Increasing bioclimatic index values superficially suggest enhanced cool-climate viticulture opportunities in England and Wales but critically mask shorter term meteorological phenomena and inter-annual weather variability that threaten productivity. These risks appear to have increased with the recent change to more ‘sensitive’ vine cultivars. Additionally, only 50% of vineyards were found to exist within modelled suitability parameters suggesting exposure to sub-optimal biophysical characteristics. However, significant opportunities for sector expansion into more suitable and meteorologically ‘stable’ areas were identified. An economic assessment of crop conversion potential indicates favourable returns for viticulture, and future climate change scenarios (2021–2040 and 2041–2060) indicate growing season warming in south-east England but a changing rainfall distribution that could threaten productivity. Champagne is projected to become drier during the critical maturation stages and the likely repetition of growing season conditions that have led to high quality Champagne vintages was found to be low. Knowledge and tools developed herein are supporting the development of climate services to aid greater resilience of the English and Welsh viticulture sectors to weather and climate risks.