The Australian wine industry is exposed and sensitive to a range of weather and climate risks. At the same time there is significant adaptive capacity within the industry. Both the climate risks and the adaptation options differ from region to region and within a region between blocks of vineyards.
The threat of climate change to the Australian wine industry is likely to come from changes in mean temperature, changes in extreme temperature events and the reduction in quality and quantity of water. Australian wine regions are distinguished by their climate (cool regions, warm regions, hot inland regions). Individual vintages are characterised by the climate. It stands to reason that changes in climate will first influence individual vintages and then overall styles of wine and finally threaten the suitability of a region for grape growing.
A series of regional workshops was held to better understand the potential impacts and to assist viticulturists to prepare for a projected warmer and very possibly drier future.
The regional workshops started with Leanne Webb (CSIRO/University of Melbourne) presenting the science of climate change and regional projections. We then used a grape phenology calendar to identify the risks to viticulture from climate and weather for their region. The confidence from climate science of these risks changing, the impact on grapevines from each risk, and management strategies for addressing these risks were presented.
The process for interpreting a region’s vulnerability to climate change included using the region’s historic climate to identify the vulnerability that the region had experienced to the risks, and to highlight the variability in recent climate that had been experienced by the region. Recently experienced climate in the region was related to what had been experienced during the World Meteorological Organization’s current climate normal period from 1961 to 1990 to highlight the nature of a continually changing climate, while future climate scenarios for the region were produced using a range of models. In both cases the impact on key climate descriptors that are related to the risks were examined. For example Growing Season Temperature (GST) or Growing Degree Days (GDD) are frequently used to determine a variety’s suitability to a region or to provide information of a season’s ranking (such as cool or warm vintages), while the number of days warmer than a particular threshold of say 35°C can be used to gauge the risk of extreme heat days or heat wave events.