Researchers found that Europe has endured the worst effects of climate change, with higher temperatures and more extreme heat days than other continents.
Dr Elizabeth Wolkovich of the University of British Columbia, who led the study, said the data was ‘sobering’.
Her team studied the phenology of grape vines, focusing on the timing of different stages of growth and reproduction in response to the changing environment.
They assessed data from more than 500 grape varieties. The study considered 10 measures of climate, from the lowest temperatures during dormancy and when buds emerge, to heat extremes during the growing season, along with temperatures and rainfall during harvest.
The researchers determined that climate change has impacted all of the world’s wine growing regions, but the effects have been uneven.
Europe has experienced the greatest shift, with significant increases in the number of days over 35°C and the highest temperatures during the growing season. By contrast, North America showed smaller increases in average temperatures and extremes.
‘I was very surprised by the level of warming across the globe, but especially in Europe, where our results show clearly just how much the growing season has warmed with human-caused climate change,’ said Dr Wolkovich,
‘As someone who has visited Europe for over 15 years, I have witnessed the increasing heat waves, but seeing the data – and how much change growers are facing – was sobering and even higher than I expected.’
This study required a ‘major interdisciplinary and international undertaking’, drawing on the expertise of climatologists, crop modelers, macroecologists and wine grape genetics experts from France, Spain, the United States and Canada.
The researchers also relied on extensive data resources, particularly from the INRAE experimental unit Domaine de Vassal, which has collected data on wine grapes for decades.
Dr Wolkovich added: ‘The fact that the biggest shifts were in heat extremes and metrics related to total heat was also surprising as we tend to expect climate change to warm minimum temperatures more – so I expected metrics like cold temperatures around the time of budburst and harvest to change the most – but it was often the metrics related to higher temperatures.’
