Using producers’ own production and financial data from the Trangie 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.
A 20um self-replacing merino enterprise on an annual grass, sub clover and native grass pasture.
Weather predictions & pasture production
Projected weather for the four 2030 scenarios and the impact on pasture production are shown below
- Compared to 1970-1999, over the period 2000-2009 rainfall was 6% lower, average maximum temperature was 5% higher and pasture production 15% lower
- For 2030:
- The temperature increases are consistent (+8%) but the rainfall forecast is variable ranging from a 1% increase to a 20% decrease, and averaging an 7% reduction.
- This leads, on average, to a 16% decrease in annual pasture production and to maintain minimum ground cover a decrease in stocking rate will be required
- There is some variation between the models in pasture production (from -8% to -29%) and therefore stocking rate.
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 sheep enterprises at Trangie, please click on: