Wine & Climate Change
Climate Change - Drivers & Impacts on Wine & Australian-led Research
Extreme climate events - more severe droughts, heatwaves and fires, more intense rainfall and flooding - these are all outcomes scientists were predicting decades ago. Now we are living these events. It’s impacting on Australian grape and wine production, biodiversity of our ecosystems which sustains food production, and our economies and communities.
Implications of Climate Change for Australia’s capacity to produce quality wine grapes is now profound, and will become more so in the future. Two main factors are driving this:
- Temperature is 1.5oC warmer on average than it was 30 years ago, and further increases of 1 - 1.5oC are expected pre 2050, depending on whether nations cooperate on achieving net zero emissions. This warming of Australian wine regions has had a profound impact on the seasonal patterns of grape production – as outlined below.
- Rainfall is lower than it was 30 years ago in South-Eastern and South Western Australia, as evidenced by average inflows into the Murray, now 50% of the 20th Century average.
Relationships between greenhouse gas emissions and global warming are now well understood and accepted. But the ‘devil is in the detail’ as to how global warming will influence the major climate systems that drive our weather.
- Australia has one of the most variable climates in the world, because our weather is driven by the three large oceans surrounding our continent - the Pacific, the Indian and the Great Southern Oceans. Their influence is partly driven by irregular cycles or dipoles that occur in large oceans, which in turn are driven by sea surface temperatures. These dipoles work in the following ways:
- Water evaporating from large water masses such as oceans, builds up moist vapour and air pressure above that ocean;
- Winds then build up above that ocean and tend to drive the moist air from the cooler side to the warmer side of the ocean, gathering moist air as they blow e. winds will blow from either East-to-West, or from West-to-East, depending on which side of the ocean has the warmest sea surface temperature at that time.
Currently these great oceans appear to influence our weather independently, with the weather we experience being the result of all 3 oceans’ activities. For example, if the Indian Ocean Dipole (IOD) is strongly negative, (meaning weather in SE Australia is cool and wet in Winter and Spring), it will exert a stronger influence on the growth and quality of grapes than the influenced exerted by the El Nino Southern Oscillation (ENSO), irrespective of whether the Dipole is negative or positive. The Pacific has a stronger impact in Spring and Summer on grape growth and quality than the impacts of either the Indian Ocean Dipole or the Great Southern Ocean Oscillation (SO).
The intensity and potential interaction between the Oceanic drivers of climate in a warmer world, will be critically important to Australia in the next 25 years. While no definite evidence exists for this as yet, Climate scientists are deeply concerned and actively investigating the possibility that a warmer globe may lead to the nature of these events becoming even more extreme and intense.
Professor Snow Barlow a director of Baddaginnie Run, and viticultural researcher, established the Viticultural Research Team at the University of Melbourne’ 2000 This Team established that grapes mature today up to one month earlier on average than they did 30 years ago. The Team found that in each year of the entire 30-year Study period, the date of Australia’s grape harvest commenced one day earlier than it had in the previous year – an extraordinary finding!
The research team found that higher spring temperatures are shortening the period between the vines bursting their buds and their flowering, which then leads to the earlier maturity and harvest, described above. Further, the current higher temperatures during the ripening period allow the grapes to accumulate sugar faster. Potentially, this leads to higher sugar levels at flavour maturity and harvest, and also to higher alcohol wines
Australian scientists have responded to and engaged quickly with the challenges presented by climate change, making them global leaders in Climate Change research on viticulture and wine the This is because wine growers and makers experience the impact of climate first-hand as they work. As a result, they understand intuitively the influences climate has on wine terroir – so as climate changes they engage with and try to deal with it.
Our grape producers are adapting by adopting innovative viticultural practices and introducing new vine more resilient varieties from southern Mediterranean. Winemakers are adapting by developing innovative winemaking techniques and changing wine styles to ensure the quality of Australian wine remains outstanding. But there are limits to adaptation and if the limits are exceeded and nations fail to cooperate on dealing with climate challenges, the wine industry will undergo major transformational changes in future.
Baddaginnie Run Responds to Climate Change Challenge
Thanks to Snow’s decades of involvement in Climate Change research and policy, when Baddaginnie Run established our vineyards in 1996, we were already acutely aware of the need to plan for hotter, drier days ahead. Below is Baddaginnie Run’s long-term strategy for adapting to and helping mitigate Climate Change’s impact on vines and more broadly:
- We selected grape varieties that have the capacity to produce high quality wines under warm-to-hot conditions, including Shiraz, Cabernet, Merlot and Verdelho.
- We built dams larger and deeper than the industry standards of the day recommended and used low, drip irrigation to help vines cope vines long hotter drier years
- We ran vines Nth to Sth and trained canopies to protect grapes from fierce Western sun.
- We’ve surrounded vineyards with networks of native flora bio-corridors that help ameliorate hotter on-ground temperatures, and maximise carbon sequestration.
- We invested in solar panels and batteries on our management facilities and dwelling.
How the Australian Wine Industry is responding to Climate Change
The Australian Wine Industry was the first agricultural industry in Australia to engage proactively with Climate Change, due to the very direct ways in which Climate Change impacts on both grape and wine production. The industry has developed multi-pronged adaptation strategies to meet the challenges.
In Australian Vineyards:
- Vignerons are introducing a wide range of new, longer-season grape varieties, largely from Southern Mediterranean origins.
- Viticulture techniques have been developed to delay budburst and extend the season by pruning vines in ways that encourage grapes to grow on the western side of the canopy, thereby enabling the leaves to protect grapes and avoid sunburn.
- Grape growers now pick fruit a little earlier to avoid sugar levels becoming too high.
- The bigger producers are purchasing vineyards further South or at higher elevations.
In Australian Wineries:
- New oenological techniques are being used successfully to ensure wine quality is not adversely affected by the hotter days the grapes experience during ripening.
- Winemakers are now being permitted by the Australian Wine Industry to add small quantities of water to wine, to avoid alcohol levels becoming too high. This is to ameliorate the situation in which today’s higher temperatures are causing higher sugar-content in the grapes, which in turn is causing higher alcohol-levels in wines.
- Wineries are installing solar panels to minimise carbon foot-print and save costs.