Wine
How does Climate Change in Australia effect winemaking?
The very serious issue of climate change in Australia is affecting us all. Here, we discuss the effect of climate change on terroir and its implications for the Australian wine industry.
National Geographic defines climate change as a long-term shift in global or regional climate patterns. It may cause weather patterns to be less predictable, making it difficult to maintain and grow crops because expected temperature and rainfall levels can no longer be relied on. Climate change has also been connected with other damaging weather events, including more frequent and intense droughts, hurricanes, floods, hail storms, and frost.
Wine Australia is the Australian grape and wine sector’s statutory body for research, innovation, marketing, and regulation. On its website, it states that “climate change in Australia is already impacting the grape and wine community, as evidenced by changes in grape phenology and harvest dates, which has led to compressed harvests and greater pressure on vineyard and winery infrastructure. Vulnerability to the impacts of climate change varies along the value chain, with the vineyard being the most vulnerable.
“The ability to manage the impact of heatwaves, drought, increased fire risk and salinity to mitigate their effect on grapevine physiology, and grape and wine quality, has become an integral part of vineyard management in the Australian grape and wine community.”
To investigate this subject further, we asked award-winning winemaker Cath Oates from Oates Ends, located in Wetern Australia’s Margaret River sub-region of Wilyabrup, two very important questions.
Q. HOW DOES CLIMATE CHANGE IN AUSTRALIA AFFECT WINEMAKING?
A. Climate change in Australia is creating issues for viticulturists and winemakers due to the increasing variability of the growing season. Regions that have traditionally been considered very stable are now showing wider vintage conditions than usual. Reducing winter rainfall in some areas, including here in Margaret River, means producers who irrigate are looking at increasing dam capacity for storage. Longer, dryer summers also may lead to consideration of some irrigation to protect older vines, where traditionally they have just been dry grown, as they can access sub-surface water throughout the growing season, or there may have been a few scattered and beneficial rain events in normal vintages. More vineyards now are maintaining permanent cover crops swards mid-row to protect the soil from heat and retain organic matter and moisture.
Q. HOW ARE VINEYARDS BEING ADAPTED TO ACCOMMODATE CLIMATE CHANGE IN AUSTRALIA?
A. Vineyard management has a wealth of tools winemakers can use; in the 2024 vintage, which was forecasted to be warm and dry, there tended to be less leaf plucking than in the cooler, moister vintages — so looking for protection of grapes from midday sun rather than promoting exposure and airflow to avoid disease. The ultimate winemaker lever is the harvest date. Harvest dates tend to be earlier in warmer vintages, with winemakers picking to retain acidity and avoid excessive sugar and ripeness. A spread of varieties is a good insurance policy, and it has been interesting to see the Tempranillo over the succession of quick vintages here, with them happily soaking up the sun in 2022 and 2024. One of Australia’s climate change outcomes is vintage compression, which can make it difficult to pick everything at optimum ripeness when capacity becomes a limiting factor; many winemakers are increasing fermentation capacity to ensure they can manage if they need to shave a few weeks off vintage.
On its website, Wine Australia also adds that some of the adaptation responses in Australian vineyards have included:
- Increased irrigation efficiency
- Modified irrigation practices in response to heatwaves and frosts
- Vineyard floor management practices aimed at retaining soil moisture
- Use of alternative varieties and/or rootstocks
- Modified canopy management practices
- Establishment of vineyards in cooler regions and/or sourcing cooler climate fruit
- Delayed pruning practices to manipulate harvest dates.
Are you interested in further information regarding the effect of climate change on winemaking in Australia?
A three-year project involving Wine Australia and the University of Tasmania has generated climate projections for Australia’s wine regions and provided detailed information about how the climate may change in the near, mid, and long term (out to 2100).
One of the outcomes was Australia’s Wine Future: A Climate Atlas, a free online resource of climate information for all Australian Geographic Indications (GI).