When people think of climate change, their minds often wander to the major issues that it causes. From the saturation o the Earth’s atmosphere with greenhouse gases, to the melting of the polar icecaps, climate change is responsible for so many things that may have a massive bearing on the future of humanity.
As massive as those effects may be, the changing climates have also caused issues in the Italian wine industry. Unexpected seasonal changes make it harder for winemakers to predict and manage the growth of their grapes, with some weather issues even causing problems for entire vintages.
Grapes are some of the most responsive fruits around, which means that even slight changes in their environments can drastically affect their quality. Let’s look at the issues that climate change has caused in viticulture in some more detail.
The most obvious effect of climate change is the increasing of temperatures, a phenomenon that many dub global warming. The effects of global warming are anticipated to affect the northern hemisphere more so than the southern, which places some of the world’s most important winemaking countries, including Italy, Spain, and France, at risk.
Temperature has an enormous effect on grape growing, not least because the temperatures of the winter period affect how and when grapes bud from one year into the next. In particular, sustained periods of warm temperatures can directly affect a grapes quality. Such periods cause grapes to lose their aroma and colour, in addition to affecting how much sugar the grape produces. All of these are vital components in the makeup of the grape and, by extension, the wines that producers make using them.
Wine producers prefer sustained periods of intermediate weather, with little variation in the day-to-day cycle. The uncertainty that surrounds global warming means that winemakers can no longer feel comfortable in the idea that they will enjoy these ideal conditions, which shows in the quality of the grapes they can produce.
Beyond early budding, global warming has the odd effect of bringing along seasonal changes where they should not exist. For example, climate change could, and sometimes does, lead to frosting during the peak summer months. Even a day or two in these conditions can have a drastic effect on the quality of the grape. In fact, unexpected cold snaps can lead to lower grape yields, in addition to hurting the general fruitfulness of the grape. As the presence of phenolic compounds in wine are affected heavily by temperature, an increase in average temperatures will affect their presence in wine regions and will therefore affect grape quality.
While temperatures are the main issue when it comes to wine production, the other effects of global warming can cause just as many problems for winemakers. For example, changing rainy seasons can prevent grapes from getting the important water they need to need to grow healthily, while preventing producers from making up the shortfall with other methods.
Conversely, increases rainfall can lead to soil erosion, which alters the consistency and quality of the terroir. With so much importance placed on the region that a wine comes from, any changes to the consistency and quality of the soil can have extremely detrimental effects on the wines those regions produce.
Producers prefer for the majority of rainfall to occur during the early stages of the growing period, when the grape is still growing and thus needs every bit of help it can get to reach its full potential. The dry periods are needed for the ripening and flowering periods. Unfortunately, climate change has an effect on both, causing rain during dry periods and preventing rain from falling when it is needed most.
Carbon Dioxide Levels
Of all of the greenhouse gases, it is perhaps carbon dioxide (CO2) that is the most infamous. Produced all over the world, CO2 has a massive effect on the Earth’s atmosphere, with plants bearing many of the problems that increased amounts of CO2 in the air cause.
If you remember you high school science lessons, you will know that plants absorb carbon dioxide in the ait via a process called photosynthesis. The plant then releases oxygen into the air, which we breathe.
However, increased CO2 levels stimulate photosynthesis beyond its usual rates, which can lead to many grapes growing dry vegetation and other undesirable plant matter. While this may not seem like much of a problem at first, it actually create a huge burden for wine producers, who must clear this unneeded plant matter to make sure their grapes get the absolute most from the sun, soil, and water the vine absorbs.
As an aside, some evidence exists that suggests that increased levels of CO2 can also affect the structural integrity of the vines themselves, which has obvious ramifications for the grapes that grow on them.
Damage to the ozone layer means that higher levels of ultraviolet (UV) radiation now affects plants. This affects the production of a carotenoid and chlorophyll that plants need to survive, which has a direct effect on how well the plant can photosynthesize the CO2 that the plant absorbs.
Beyond that, some have linked UV radiation to changing grape aromas, which means the issue could lead to the entire structure of some of the world’s most famous wines changing over time.
The Final Word
Climate change presents one of the largest problems that mankind has ever faced. Increasing levels of greenhouse gases in the atmosphere, coupled with the many climate issues that these gases causes, have resulted in the creation of a clear and present danger that scientists are working as hard as possible to mitigate.
For winemakers, the effects of climate change are wide reaching. At best, the issue may cause the composition of their grapes to change, which results in changing aromas and inconsistent vintage quality. At worst, climate change will actively damage vines, preventing them from growing to their full potential. This will have a direct effect on wine quality and, by extension, the wine industry as a whole.