European wine suffers most from global warming, study shows

European wine has so far suffered the worst impacts of global warming, with rising temperatures and more heatwaves, according to an international study published Wednesday, although all wine-growing regions are suffering.

By cross-referencing climatic data (at flowering, at bud burst, before harvesting, etc.) and reactions according to growth stages applied to more than 500 grape varieties, the authors were able to compare the effects of disruptions from one region of the world to another.

The result: Europe suffered the most massive upheavals, with days above 35°C on a "significant increase" and the highest temperatures during ripening, reveals the analysis published in the American journal PLOS Climate.

By contrast, North America experienced more moderate increases in both average and extreme temperatures.

South America shows similar results to the European situation in terms of average temperatures, but less extreme heat, adds the study, which brought together climatologists, agronomists, ecologists and experts in vine genetics from France, Spain, the United States and Canada.

The researchers used data collected over decades by the Domaine de Vassal experimental unit, managed by the French agricultural institute INRAE.

Elsewhere, where temperatures could already reach extremes before the rise in global warming, the impacts can also be very strong (fires, etc.) with a less spectacular rise in the thermometer, as in North Africa or Australia.

The overall lesson of the study is that the vines must above all face a rise in maximum temperatures, much more than an increase in minimum temperatures or the resurgence of cold spells that occur at the wrong time.

The vine is a plant that is very sensitive to global warming and the impact of the climate is already visible in earlier harvests, higher sugar levels in production, and the emergence of new cultivation areas.

"I was very surprised by the level of warming across the globe, but particularly in Europe, where our results clearly show that the growing season has warmed due to human-related climate change," said lead author EM Wolkovich of the University of British Columbia, Canada.

"Visiting Europe for over 15 years, I've seen the rise in heat waves, but the data and the scale of change facing farmers is beyond what I expected, and it's sobering," he added.