The grapevine, an accurate thermometer of global warming

Vine growing is a centuries-old tradition in Spain, a country that houses the largest expanse of vineyards in the world, with more than 1.1 million hectares planted, and where the quality of wines has undergone revolutionary changes over the last few decades.

But this situation could change, and not just because China is hot on Spain’s heels as the second largest wine producer on the planet, but also because the vine is a plant that is extremely sensitive to temperature increases. The impact of global warming is already becoming evident in vineyards, a crop that literally has deep roots in the Mediterranean climate, and which is particularly sensitive to environmental changes.

"The temperature increase of just one degree that we have witnessed in the Penedès in the last 40 years has made our grape harvest jump ahead about 10 days, on average," says Miguel Ángel Torres, president of Bodegas Torres, whose origins date back to 1870. He added: "If the temperature continues to rise, the quality of wine will be affected, as the maturity of the grapes and the phenolic maturity will get out of sync." In his opinion, it is the greatest threat to the worldwide wine industry today and he considers it critical for governments to include the problem in their agendas, unite their efforts and make a joint commitment during what he calls the final opportunity to curb global warming: the 21st United Nations Conference on Climate Change, to be held this December in Paris.

Torres is preparing for the new climate scenario by purchasing land at higher altitudes or latitudes, and by searching for cooler climates (temperatures drop one degree for every 100 metres of altitude, or 328 feet).

A small winery, Marqués de Terán, founded in La Rioja just a decade ago, responded to the problem by becoming a global pioneer in the use of geothermal energy. "With our five wells over 100 metres deep we get the temperature required for the different processes of production and aging of wines. This way, we reduce our CO2 emissions released into the atmosphere by over 80%", says Manuel Garcia Ortega, the winery's managing director. He also refers to 'mad grapes' to explain how it gets more difficult every year to find the right moment for harvesting. "We no longer have a problem of temperature with the grapes, we always have sufficient temperature for alcoholic maturation; but the polyphenol ripening is particular to every harvest, and it's increasingly difficult to find the correct acidity. Sometimes green grapes go rotten in just two days, without maturing properly. The weather is crazy and therefore grapes go crazy," he concludes.

For Pau Roca, secretary general of the Spanish Wine Federation (FEV), data from recent studies on global warming is alarming, specifically regarding its impact on vineyards. "If no action is taken, crops will move to cooler zones and, in fact, it is already happening." He believes the industry is well aware of the problem, "it has never been in denial." This approach probably stems from the fact that wineries, many of them centuries old, have an extraordinarily valuable historical memory: information kept, harvest after harvest, for years, both for vintages and samplings of wine, winemaker records for changes in production processes and cultivation, etc. He says that "the evolution of vine growing is symptomatic of climate change".

In 2011, the Wineries for Climate Protection (WFCP) movement was born in Spain, driven by the FEV. Many wineries subscribed to a set of commitments to be more responsible and active in the face of global warming and its consequences. Now, the FEV has designed the first and only specific certification for the wine industry in environmental sustainability, and it aims to establish it as an international benchmark.

Another century-old winery, Faustino, acknowledges that over recent years it has faced many challenges in its wine production that ‘might’ be attributed to climate change. "We say 'might', because climate change is difficult to prove, although by observing the evolution of the grape in recent years and therefore, of wine, there might be a relationship with this phenomenon."

Well aware of the harm brought on by global warming, the wine group Matarromera, present in several wine regions, has led comprehensive research on the effects of climate change on vine growing and wine making through the Cenit Demeter project, which brought together 69 designations of origin and 5,000 wineries. In addition, it is investigating new methods of producing the Verdejo white grape variety as it faces climate change.

Grapevines may withstand warmer temperatures of one or two degrees this century, but if the temperature rises four or five degrees, as experts predict, the consequences will be disastrous for the culture of grapevine cultivation, which, through millennia of experimentation, established the best locations for each grape variety. Miguel Ángel Torres adds that "the day might come when we will have to face substituting some varieties with others." He forecasts that "the map of designations of origin may change not only in Spain, but across the whole of Europe".

COMMENT NOW