Wine Making in a Warmer World

I was reading one of my wine news feeds which had this article: Climate change is altering the chemistry of wine. The article touched on the effect of fires on grapes as well as rising temperatures and the unpredictability of current weather patterns on winemaking and wine.
The Problem
For wine grape growing, a region’s climate change can disrupt the balance of sugar, acid and secondary compounds by changing the rate at which they develop over the growing season. A warmer growing season generates lots of sugars, fewer acids and undesirable changes in aromas.

Warmer temperatures affect the rate at which sugar and acids are accumulated in a grape berry. The amount of sugar is important because that is what the yeast converts into alcohol. A berry which is higher in sugar content leads to a wine with a higher level of alcohol. In addition, the flavor of a very ripe berry is more like raisins leading to a boozy, raisiny, "cooked" tasting wine and the drop in acidity affects the longevity of the wine in the cellar.
The Solution
All of this has an impact on the wine and blurrs the sense of place, or "terroir" of a wine grown in a specific region.

• In Bordeaux, for example, a traditional style for red wines is full-bodied with strong fruity aromas and a “pencil lead” earthiness. An earlier spring means that the grapes of traditional varieties mature during the peak of summer rather than in the fall, generating lots of sugars, fewer acids and undesirable changes in aromas.
  In the past, Bordeaux was allowed to grow 6 red varieties (Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot, Malbec, and occasionally Carménère) and 8 white varieties (Sémillon, Sauvignon Blanc, Sauvignon Gris, Muscadelle, Colombard, Ugni Blanc, Merlot Blanc and Mauzac).
  The unprecedented solution in Bordeaux as of 2021, is to allow the wine grape growers to grow an additional 4 red (Arinarnoa, Castets, Marselan and Touriga Nacional) and 2 white (Alvarinho and Liliorila) varieties. For the red Bordeaux, the addition of the French variety Arinarnoa can boost acidity and tannin levels and the Portuguese Touriga Nacional can ramp up powerful black fruit aromas that heat-sensitive varieties might lose. The caveat is that the final wine blend cannot contain more than 10% of these newly allowed grape varieties.
• Another solution researched by plant physiologist, Gregory Gambetta at Bordeaux Sciences Agro and the Institute of Vine and Wine Science is to study how to climate-proof vines by using different rootstocks. Rootstocks control a plant’s overall vigor and water use and maybe selected to tolerate the warming world. UC Davis viticulture researcher Kaan Kurtural has been testing this hypothesis at the Oakville Experimental Vineyard in Napa Valley since 2016. Kurtural his colleagues have been monitoring 16 unique combinations of rootstocks and Cabernet Sauvignon clones to learn which combinations are most resilient under stressful conditions like heat waves and drought while still producing high-quality Cabernet Sauvignon grapes. So far, the Austrian rootstock Kober 5 BB, the French 3309 Couderc and 110 Richter have looked promising.
• Investigating the effects of different viticultural practices, including a carbon-sucking grass that can grow between rows and vines tied up to wires in numerous trellising styles
• The use of shade films to slow the ripening process to selectively filter the UV spectra to prevent the loss of heat sensitive flavor compounds
• Adapt winemaking techniques to produce a well rounded wine with riper grapes

References:
1. Ula Chrobak and Katarina Zimmer, Knowable Magazine, Climate change is altering the chemistry of wine, June 22, 2022.
2. Roger Voss and Kathleen Buckley, Beverage Industry Enthusiast, Bordeaux Aims to Protect its Future with New Grape Varieties
3. Wine Industry Network, Bordeaux Receives National Approval to Introduce Six New Red and White Grape Varieties in 2021, January 26, 2021.