Using producers’ own production and financial data from the Yarrawalla region, modelling was initially undertaken to assess pasture and livestock production, and enterprise profitability for two prior periods (1970-1999 and 2000-2009) to ensure the models were performing correctly. Modelling was then performed looking ahead to 2030, using 4 different climate scenarios.
The enterprise modelled was a dual purpose terminal sire x merino ewes (not self-replacing)
Grazing was on annual pastures plus crop stubble, on red loams over clay soils
Weather predictions & pasture production
Projected weather for the four 2030 scenarios and the impact on pasture production are shown below
- Compared to the period 1970-1999, in 2000-2009:
- Average annual rainfall was down 4% while average daily temperature was up 2%.
- Annual pasture production was down by 17%.
- Looking forward to 2030, compared to the base period 1970 – 1999, the 4 different climate scenarios showed:
- Average daily temperature increase is pretty consistent across the 4 scenarios by about 1°C (+6%)
- Average annual rainfall was slightly more variable – averaging 2% lower but ranging from +2% to -7% decrease.
- This leads, on average, to a 9% decrease in annual pasture production (but ranges from 23% lower to 5% higher).
- Predicted pasture production in 2030 is, on average, not dissimilar to that experienced during 2000-2009.
- Three of the four GCM’s indicated a reduction in winter-spring rain and an increase in summer rain
Livestock & Financial Impacts, and Adaptations
Using the modelled pasture production figures, the impacts on livestock production and farm profitability were then calculated. Such impacts were initially based on a “business as usual” case i.e. no adaptations (changes to farm management practices) were made.
Then, by discussing these predicted results with farmers, a series of possible adaptations were agreed to and modelled. These adaptations were assessed for their ability (either individually or in combination) to help reduce the impact of climate change on livestock production and farm profitability.
To see the ‘business as usual’ impacts, and then what adaptations were proposed by producers and modelled, for the enterprise at Yarrawalla, please click on: