In focus: How the Australian wine industry is dealing with climate change
Climate change is having a major effect on Australia’s wineries, as temperatures rise and water becomes increasingly scarce. Phoebe French speaks to winemakers in the country about how they are adapting to increasingly erratic conditions.
Last summer was Australia’s hottest on record. It was also one of the 10 driest the country has experienced, with only parts of northern Queensland and northwest Victoria exposed to above-average rainfall.
The Australian Government Bureau of Meteorology revealed that 2018 was Australia’s third-warmest year on record, with the annual national mean temperature 1.14 °C above average. The potential for an El Niño warming weather pattern remains, with a 50% chance of it developing during the southern hemisphere’s autumn or winter this year – twice the normal likelihood.
With extreme temperature spikes and unsettled weather becoming more frequent, how is climate change affecting the nation’s AU$6 billion (£3.3bn) wine industry? And in a country covering 7.69 million square kilometres, with 65 registered wine regions and 140,000 hectares under vine, is it even possible to generalise?
“Contrary to what President Trump suggests, it’s not ‘just weather’, and we can’t bury our heads in the sand,” says Paul Braydon, buyer at UK wine supplier Kingsland Drinks, which works with wineries based in Victoria, South Australia and New South Wales .
He recounts how this year, while the vintage is not yet complete, there are early indications that “significant weather events” have led to a fall in production volumes and a rise in grape prices.
Braydon adds: “Forecasts are for volumes to be 30-50% down this year from the premium regions including Barossa, McLaren Vale and Clare Valley, and 10-30% from the Riverland. Grape prices are up by around 25% for red varieties to around AU$600 per tonne and 9% for whites to AU$375 per tonne, compared with 2018. Water is now AU$570/ml for temporary water rights.”
According to a 2011 study, published in Global Change Biology, observing changes in grape maturity in Australia, Webb, Whetton and Barlow examined the records of 44 sites, finding that grapes ripened at a rate of 1.7 days earlier between 1993 and 2009.
A study in 2012 in Nature Climate Change published by Webb, Whetton, Bhend, Darbyshire, Briggs and Barlow found that warmer temperatures and lower soil-moisture levels contributed to this alteration.
It noted, in the period from 1985 to 2009, that grape maturation dates had advanced by eight days per decade in southern Australia. Nine out of 10 sites studied exhibited earlier ripening trends, with only vineyards in Margaret River in Western Australia showing later ripening when observed over the full period of 1977 to 2009.
Geoff Merrill, owner and winemaker of his eponymous wine label in McLaren Vale, agrees with the findings. “Over the past 20 years we have seen an average shift in harvest date by approximately two weeks earlier than the past,” he says.
He also notes that not only has the vintage been brought forward, but it has also been compressed. “The beginning of the vintage may be two weeks earlier, but the duration of the vintage is much shorter. We must crush more per week than ever before,” he adds.
Neil McGuigan, CEO of Australian Vintage, which owns McGuigan Wines, Tempus Two and Nepenthe, explains that needing to get grapes off the vines faster has resulted in significant investment in harvesting and winery equipment.
“To ensure grapes are being harvested at the optimum level of ripeness, winemakers are starting to use more processing equipment to increase the amount of grapes that can be picked per day,” he says. “As temperatures get warmer we have to invest in products to offset the seasonal variations. We are doing this by making sure we have the capacity to cope with a higher influx of grapes at one given time.”
The winery is not the only area where investment is being made. In the vineyard too, winemakers have adopted practices to cope with the heat. Growing a larger leaf canopy to generate shade and protect grapes from sunburn is becoming very important, says Merrill.
In research published in January 2019, Charles Sturt University postdoctoral researcher, Dr Joanna Gambetta, from the National Wine and Grape Industry Centre (NWGIC) said sunburn can affect up to 15% of wine grapes in Australia in any given season.
“The browning, cracking and berry shrivelling means that yields are reduced and the fruit can be downgraded, causing significant economic losses to growers and wineries,” she says.
“On a sensitive, fully mature Chardonnay grape, symptoms of sunburn can appear within five minutes once surface temperature on the berry reaches an ambient temperature of 40–43°C.”
Adam Levy, founder of International Beverages Competitions, notes the creative ways in which Australian winemakers are adapting to change to ensure grape- and wine quality are not affected. “Some are experimenting with new grapes that may be able to handle the climate disruption,” he says. “Others are looking for better ways to control the moisture of the soil to reduce sudden and extreme differences. Some are also looking at land at higher altitude to combat the rising heat, which leads winemakers to review their use of land.”
Techniques including mulching and low-growing cover crops to retain soil moisture, planting at higher altitudes, growing hot-climate and drought-tolerant varieties including Tempranillo, Assyrtiko and Nero d’Avola, and even putting special ‘sun cream’ on grapes, are all being implemented in Australia.