Climate change: towards an evolution of the Mediterranean vine-growing area
With climate change, iconic Mediterranean crops will see their distribution areas change. Serge Zaka, agroclimatologist, explains how the biogeography of vines in the Mediterranean will evolve in the coming years, based on models he carried out as part of the AACC-Med project.
Biogeography is a term used to talk about the species' distribution areaThis definition can be extended to vine varieties. Since species or grape varieties do not thrive in all climates, their biogeography depends in particular on climatic conditions. Thus, in a context of climate change-induced climate change, biogeographies are also likely to evolve.
Since the beginnings of agriculture, humans have exploited each agricultural species in biogeographies that allowed them to maximize their production in both quality and quantity. That is to say, they sought the environmental conditions (climate, pedology, etc.) closest to the optimum growth and development for each production (the establishment of economic sectors was added later).
What is the Mediterranean climate?
It is a temperate climate type characterized by hot, dry summers and mild winters.
It is distinguished mainly by the coincidence between the annual rainfall minimum and thermal maximum, which means that the hottest season is also the least rainy. The main characteristics of this climate are very hot summers, reaching 35-40°C, mild winters, with temperatures rarely below 0°C, significant sunshine, and rainfall concentrated in autumn and winter. It is not only found in the Mediterranean region, but is also characteristic of the coastal regions of southern California, central Chile, southwestern Australia, and the Cape region of South Africa.
The cultivation of vines and grapes has gradually conquered all Mediterranean climates
Within this vast biogeography of the vine, we observe a gradient of grape varieties and winemaking practices depending on the distance from the equator. Each grape variety thus has its own biogeography, adapted to a specific climate. This balance between quality and quantity has been refined over the centuries, anchoring the different terroirs and the appellations associated with them.
However, the terroir, which is based on a trilogy between humans, soil, and climate, is today threatened by climate change. This is modifying all terroirs across the world, calling into question a balance shaped by humans for centuries.
Anticipating has become essential
The vine, a long-lived species—which can reach over 50 years—requires us to start thinking now about the future of our terroirs. This begins with an in-depth study of the biogeography of each grape variety to ensure their adaptation to new climatic conditions.
Animation of changes in vine cultivation areas between 1960 and 2100
Developed in 1974 at the University of California, Davis, by AJ Winkler and Maynard Amerine, the Winkler index is an agroclimatic indicator used to classify different wine production areas (grape varieties and types of wine). It is the cumulative temperature above 10°C between April and October (northern hemisphere); 10°C is considered the minimum temperature for the physiological activity of the vine.
With the rise in temperature, Climate change redefines Winkler index zones across the Mediterranean.
As the maps above show, new wine-growing lands will thus be potentially exploitable in Central and Northern Europe, such as England or Belgium. Conversely, the surface area of wine-growing lands will shrink in the Mediterranean. They will even disappear in North Africa, Andalusia, parts of Italy and Greece. At the same time, vines will rise in altitude. Some reliefs in the Mediterranean zone will potentially see vines flourish on their slopes. The Mediterranean zone is also one of the areas on the globe where vines will be most affected. These changes underline the crucial importance of anticipating the future of our wine-growing terroirs now and of supporting the adaptation of Mediterranean agriculture as best as possible.
Learn more:
On the AACC-Med project : https://fondation-farm.org/projet/aaccmed/
Download the white paper The urgency of adaptation and find other maps and analyses: https://fondation-farm.org/projet-aacc-med-livre-blanc/
