Article: Hannah, Lee, Patrick R. Roehrdanz, Makihiko Ikegami, Anderson V. Shepard, M. Rebecca Shaw, Gary Tabor, Lu Zhi, Pablo A. Marquet, and Robert J. Hijmans. “Climate change, wine, and conservation.” Proceedings of the National Academy of Sciences 110, no. 17 (2013): 6907-6912. Doi: doi.org/10.1073/pnas.1210127110
Our changing climate (Marcott et al., 2013) is at the forefront of global politics and economic planning decisions. There is growing evidence that climate change will affect most fields of study and many professions from agriculture to zoning. One such field that is gaining attention is viticulture, or wine production. A study published in PNAS led by Dr. Hannah and colleagues (2013) looked at how changes in temperature and precipitation will affect global wine production. In addition, the researchers explored how the locations of wine-making regions may shift due to climate stress, and how this might affect conservation.
Exploring wine-making as a tool to study climate change
Climate change will directly and indirectly impact ecosystems. In response to climate change researchers have investigated the seasonal changes in animals and plants (Walther et al., 2002; Bale et al., 2002) for the past decade or so to track direct changes in the habitats and behaviors of species. Recent studies have also explored creative ways to study the indirect effects of climate change. A study conducted in 2013 investigated wine grape production as a test bed to measure the indirect impacts of climate changes as observed in agriculture. Wine-making is concentrated in Mediterranean climate regions that are sensitive to temperature and moisture changes (Figure1) and are global biodiversity hotspots. Furthermore, the authors put forward the idea that wine production might impact freshwater conservation, as the warming climate may cause increased irrigation to be required. As wine production regions migrate north in response to climate change, there is concern that they may encroach on valuable environments that need to be conserved in their natural state.
Models to the rescue
The authors predicted how climate change could affect wine production using suitability models. Suitability models represent a range of global climate models (GCMs) in addition to measuring an “ecological footprint” index. The models can be used to look at ecosystem changes associated with different future climate change scenarios. For further reading on using models for different scenarios check out this post by SkepticalScience.
What were the results?
Based on various model outputs, Hannah et al. observed that the land suitability of wine production is projected to decline in many traditional wine-producing regions (the Bordeaux and Rhone valley regions in France and Tuscany in Italy) and increase in more northern regions in North America and Europe (Figure2). Water use for wine production may increase in traditional wine growing areas, as vineyards will need additional water for misting or sprinkling to reduce grape temperature on the vine to adapt to climate change. Chile was the region most likely to be severely affected by freshwater scarcity by 2050, followed closely by Mediterranean Europe and California. The authors suggest that the majority of premium wine-producing landscapes in Chile (Maipo, Cachapoal, and Colchagua) will become mostly unsuitable. The reason, according to the authors, is that Chile’s agricultural activities depend on water derived from snowmelt, which are particularly vulnerable to climate change. Increasing water demands paired with a decrease in snowmelt will threaten Chile’s freshwater systems. North America will be most greatly impacted around the Rocky Mountain region near Canadian/US border. Higher latitude regions are likely to become more suitable for wine production as global temperatures rise. Vineyards are already rapidly expanding in areas near the Columbia River basin of eastern Washington, the Snake River valley of Idaho, and the Okanagan Valley in British Columbia encroaching valuable environments.
Wine under a hot world
Wines represent comradery and enjoyment across cultures. However, with a changing climate, the authors of this study conclude that the shifting geography of wine grape production will have substantial implications for conservation. Hannah et al. provide an example of a vineyard industry-led effort in South Africa which avoids areas of high conservation importance. A growing and increasingly affluent global population will likely create an increasing demand for wine. To ensure we don’t overuse the land, it is vital for wine-making to adapt to sustainable and ecosystem conscious methods that consider secondary impacts of agricultural change on ecosystems and biodiversity.
Note: Featured image is credited to grapes from Chateau Subilaux, Bordeaux, France. Commonly used to make Bordeaux blends.
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Marcott, Shaun A., Jeremy D. Shakun, Peter U. Clark, and Alan C. Mix. “A reconstruction of regional and global temperature for the past 11,300 years.” science 339, no. 6124 (2013): 1198-1201.
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