Multivariate Climate Analogues for Australian Viticulture Regions Under Climate Change

Background and Aims Climate is important to consider for viticulture, including its influence on grape development, yield and wine quality. The climate has already changed and is projected to change further into the future, so there is a need to understand these changes for viticulture regions. New methodologies and datasets are used here for insight into the climatology of five Australian viticulture regions, including observed changes over recent decades and projected future changes. Regions examined here are Barossa Valley (South Australia), Hunter Valley (New South Wales), Margaret River (Western Australia), Yarra Valley (Victoria) and Tamar Valley (Tasmania). Methods and Results A multivariate climate analogue method is used based on growing season temperature (GST) and growing season rainfall (GSR). This method identifies locations that have similar recent conditions (for 1980–2019) to those of an earlier period (1940–1979), analysed individually for each viticulture region. Results based on observations show these analogue areas are to the south, or at nearby higher elevations, from each of the five regions. This method is also applied to identify future locations projected to have similar climate conditions to those of the earlier time period. Future projections are obtained from a dataset comprising of multiple regional climate models (RCMs), based on a global warming level (GWL) of 1°C above the recent period 1980–2019. The future projections indicate analogue areas shifting further away from current viticulture regions, generally shifting in a similar direction to the observed changes, but with a larger magnitude spatial displacement. Conclusions These findings provide insight into how climate change has already influenced viticulture regions and how this could be projected to change further in the future. Differences between regions, such as analogue regions shifting southward or to higher elevations, highlight a need to consider climate adaptation strategies tailored to local conditions. Significance of the Study This study uses a novel multivariate analogue method based on observations, as well as an ensemble of bias‐corrected RCMs, complementary to previous studies that typically use global models or a single regional modelling approach. The results provide new insight into how climate conditions are shifting for viticulture regions, including revealing spatial details on how these shifts vary between regions. These findings are intended to help contribute to the broader set of knowledge available for guiding climate change adaptation in Australian viticulture. Potential is also noted to apply a similar methodology for other agricultural and ecological sectors.