What will the climate of a given region be like in 20, 30 or 50 years? Climate analogues provide a robust methodological framework to address this question by identifying regions whose current climate matches the future climate of another area. For the first time, a research team from the University of Geneva (UNIGE) has applied this approach to vineyards, in collaboration with Agroscope. Through a dedicated mobile application, winegrowers – but not only – can visualise the expected impacts of climate change on their vineyards by identifying regions that already experience comparable climatic conditions. This research, published in Agricultural and Forest Meteorology, is a key tool for anticipating and adapting viticultural practices in the context of climate change.
Drought, hail, emerging pathogens and earlier bud break: the effects of global warming are already being felt in vineyards. But how will these phenomena evolve over the coming decades, and what challenges will they pose for viticulture? To address these questions, a research team from the University of Geneva (UNIGE), in collaboration with Agroscope, applied the concept of climate analogues to vineyards. The objective was to develop a mobile application capable of identifying, for any given vineyard in Europe, regions whose current climate corresponds to the climatic conditions that vineyard is expected to experience in 20, 30 or 50 years.
To develop this tool, the researchers drew on several existing databases, including those from the Coordinated Regional Climate Downscaling Experiment (CORDEX), which brings together the results of numerous high-spatial-resolution regional climate models covering Europe until the end of the 21st century. Vineyard locations were extracted from the Corine Land Cover database. Overall, the application encompasses 57 wine-growing regions and more than 20,000 individual vineyard plots, with climate projections extending to 2090.
Accurate bioclimatic indicators
“We modelled the temporal evolution of six key bioclimatic indices, taking into account both vine development and pathogen-related risks, such as the number of frost days, extreme heat events and the mildew index. Microclimatic variability was fully integrated into the analysis. The application also allows users to select one or more specific indicators,” explains Héloïse Allaman, PhD student in the Department of Applied Physics at the Faculty of Science and in the Institute of Environmental Sciences (ISE) at UNIGE, and lead author of the study.
“Temperature-related indices primarily drive north–south and altitudinal shifts in climate analogues, whereas pathogen-related indices, which incorporate humidity and precipitation, tend to produce east–west shifts. These contrasting effects highlight the importance of integrating all relevant indices in order to accurately identify climate analogues,” explains Stéphane Goyette, senior research scientist and lecturer in the Department of Applied Physics at the Faculty of Science and in the Institute of Environmental Sciences (ISE) at UNIGE, and co-author of the study. ‘‘Taking into account indicators of diseases and pests makes projections more accurate, as it considers phytosanitary factors that affect vines and not just the climate,’’ adds Pierre-Henri Dubuis, a research associate at Agroscope.
Inevitable Adaptations
For example, what conditions will vineyards in Dardagny, Canton of Geneva, face by 2070? According to the mobile app, these conditions will be similar to those currently observed in Saint-Matré, in southwestern France, around 100 kilometres from Toulouse. This information allows Geneva winegrowers to anticipate the impact of climate change by studying the practices employed in their future climate “twin”.
"Overall, the study reveals a shift in viticultural suitability – the ability of a region to sustainably produce high-quality grapes – towards northern Europe and areas that are on average 650 metres higher than today. However, the predicted increase in humidity in most of these new regions could compromise the long-term sustainability of viticulture by intensifying disease pressure. The wine industry will therefore have to anticipate major geographical changes and adapt its practices by the end of the century," says Jérôme Kasparian, professor in the Department of Applied Physics at the Faculty of Science and director of the Institute of Environmental Sciences (ISE) at UNIGE, who led the study.
The “Climate Analogues – Vineyards” app is available free of charge and can be downloaded from the official iOS and Android stores.