Western Australian agriculture has always been shaped by climate. In recent decades, however, rainfall has declined, droughts are more frequent. If the trend continues farmers across the Great Southern and Eastern Wheatbelt will likely need to adapt. In this report we outline how a drier future will influence farm profitability, greenhouse gas (GHG) emissions, and management decisions.
Great Southern
As drought years become more common, farm profitability is reduced. Modelling shows that doubling the probability of consecutive droughts (defined as years with decile 3 or lower rainfall) cuts expected profit by around $52,000 per year.
However, it’s not just the total amount of rain that matters — the pattern of drying can shift profitability by up to 26%. Seasons with late breaks are especially damaging, even more so than dry springs, despite springs reducing total growing-season rainfall to a greater extent. The reason is that late breaks reduce crop establishment and restrict early pasture growth, tightening feed supply at a critical point for livestock and driving up supplementary feeding costs. These timing effects also alter the best management responses, with optimal stocking rates and pasture allocations shifting by around 20–24% depending on how the climate dries.
The analysis shows that with optimal management adjustments, losses from a drying climate can be partly offset. Strategic changes were minimal — for example, only a slight reduction in stocking rate was required under future scenarios. Most of the resilience comes from tactical decisions made as the season unfolds. This flexibility allows farmers to limit losses in poor years without missing opportunities in favourable ones. Tactics included adjusting stocking rates, crop rotations, sale timing, grazing pressure, and supplementary feeding (see past article on tactical management).
Despite the financial impact of more droughts, the overall conclusion is reassuring: farmers in the Central Great Southern are likely to remain viable under a drying climate. Profitability will continue to depend on how the climate dries, how prices evolve, and what other production efficiencies are achieved.
Eastern Wheatbelt
In the Eastern Wheatbelt, the financial impact of a drying climate is even greater. Modelling shows that a 10% increase in the frequency of drought years reduces expected profit by around $91,000 per year. As in the Great Southern, it is not just the amount of rainfall that matters but also when it arrives.
Management adjustments can partly offset these losses. Strategic changes — particularly reducing stocking rates and increasing the share of land allocated to pasture — improved profitability by about 18% under a drier climate. Tactical adjustments also became more important, with greater year-to-year swings in land use allocation and stocking rates as farmers responded to seasonal conditions. Although, the economic value of these tactical shifts was not quantified.
Greenhouse gas emissions are also affected. A drying climate reduces total farm GHG emissions simply because less is produced, but emissions intensity (per unit of product) increases, reflecting the reduced efficiency of production.
Looking Ahead
The research is clear: Western Australian farms can adapt, but the path forward will require a mix of strategic planning and tactical agility. Improvements in genetics, feedbase management, and technology—combined with realistic climate modelling—will be essential to help farms remain profitable and sustainable in the face of a drying climate.
🌱 This project was funded by the MLA Donor Company with matching funds from the Australian Government and delivered in collaboration with DPIRD.