The researchers looked at the relationships between temperature, rainfall, extreme weather events and yield in England's main grape-growing regions, and surveyed wine producers for their views on the role of climate change in the success of English wine.
"Our findings identify threats to the industry as well as opportunities," said lead researcher Alistair Nesbitt. "While average temperatures over the growing season have been above a key minimum threshold for cool-climate viticulture for two decades, wine yields vary. Producers recognised the contribution of climate change to the sectors recent growth, but also expressed concerns about threats posed by changing conditions."
June rainfall was found to be the strongest indicator in explaining year-to-year yield variability, as cool, wet weather at this time delays flowering and reduces berry formation, while frosts pose a particularly high threat to yields if they occur at critical times such as soon after bud-burst. The bumper years of 1996, 2006 and 2010 are attributed to warm springs and autumns and the absence of frosts at critical times.
Nesbitt added: "Between 1989 and 2013 there were ten years where the temperature was 14 degsC or higher - around the same temperature as the sparkling wine producing region in Champagne during the 1960s, '70s and '80s. However, UK wine yields are very low by comparison. In Champagne, yields can be more than 10,000 litres per hectare, but in the UK, it is around 2,100 on average."
And he warned: "The impact of short-term weather events such as cold snaps, sharp frosts, and downpours will continue to threaten productivity."
The UK has been warming faster than the global average since 1960. Over the past decade, land used for viticulture in England has increased by two and a half times to around 1,900 hectares.
The paper 'Climate and weather impacts on UK viticulture' is published in the Australian Journal of Grape and Wine Research.