Bordeaux and Global Warming





This was one of the main topics discussed at the Wine and Climate Change conference held in Barcelona in February 2008.


Opinions are divided. Wine consultant Michel Rolland and winemaker Jacques Lurton, by and large, have seen the warmer climate in recent years as being largely beneficial to Bordeaux - longer growing seasons, riper grapes, rounder and fuller resulting wines.

And by and large, according to canopy management expert (and brilliant speaker) Richard Smart, existing cool regions such as Bordeaux will do best if they can accept that their international reputation will have to change as variety-suitability changes.

And that surely will be the sticking point for Bordeaux. In fact all of France - will the bureaucracy and tight regulations overseeing everything from yield to grape variety, move quickly enough to keep uo with the inevitable march of the changing climate?

In terms of more concrete changes - we already know that harvests are getting earlier (average two weeks earlier than 10 years ago), and alcohol levels are rising. A few interesting questions: will today's sought after terroirs (the 'hot' gravelly terroirs of the Left Bank) give way to cooler clay climates of the Right Bank? Will merlot survive, given its propensity to over-ripen quickly? Will the old 'forgotten' Bordeaux grape varieties, such as Malbec and Carmanere, make a come-back here as they are better adapted to hot climates? Certainly Petit Verdot is already doing well out of longer growing seasons.

An what will this mean for consumers? There are also two schools of thought about who will do best at convincing customers to accept the new realities. The New World has an advantage in that its present regions are not so well known to consumers, so if producers do need to develop new cooler regions, it won’t matter so much from a marketing point of view. However, the New World has hung its hat on varietal labelling for the past decade, so if there is a need to change varietals, or to produce entirely new hybrids, they may encounter more resistance – whereas if Old World regions such as Bordeaux simply change the grape varieties, or blend their wines differently, they won’t need to change their entire appellation-led labelling, thus keeping a ‘recognised’ name to reassure the end consumer.

Global Warming and Cabernet Sauvignon

As temperatures rise what will be the future for the variety? Cabernet sauvignon is a variety suited to the warmer end of the range in terms of growing conditions (as opposed to, for example, Pinot Noir), which probably means that it is less vulnerable to warming than other varieties, and new areas which are now too cold could become suitable, such as New Zealand, Northern France, even Germany.

In the world’s two key Cabernet areas, there are very different reactions. Wine consultant Michel Rolland said at a recent climate conference that, ‘Global warming can only be good for Bordeaux, allowing for the richer, rounder wines we have seen in recent years’. Kim Nicholas Cahill, Department of Global Ecology at Stanford University, sees things rather less optimistically. ’Our research shows that, for wine grape varieties as a whole, California is within 1 degree Centigrade of a peak where warmer spring temperatures would no longer help and may hurt wine grape yields. Some of our other research shows that the temperature during the last month or so of ripening is quite important to California Cabernet quality (as measured by wine scores), so warmer summers (average) or more heat spikes (extremes) are likely to be negative for quality in many cases.’