Using producers’ own production and financial data from the Glen Innes 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 18 um self-replacing merino flock was examined.
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 10% lower, average maximum temperature was 3% higher and pasture production 8% lower
- For 2030:
- Glen Innes is quite unique in the SLA2030 project
- Unlike most other sites in NSW, a decrease in rainfall does not necessarily lead to a decrease in pasture production. This site is at 1060m so the cold winter temperatures are a major constraint on pasture production. The increase in temperature is buffering the decline in rainfall. The driest model does show there is a limit to this buffering capacity and that all production factors can drop below base.
- The temperature increases are fairly consistent across the four scenarios (+9%) but the rainfall forecast is more variable from a 7% to a 17% decrease (average 10% decrease).
- This leads, on average, to an increase (+1%) in annual pasture production, with a range of +8% to -8%.
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.
As there was little difference in pasture and livestock production, and profitability under the four climate scenarios to 2030, no adaptations were modelled
- Compared to 1970-1999, stocking rate and profit changed only marginally over the period 2000-2009
- For 2030, while there was some variation in the impact of the 4 climate scenarios examined these were, relative to other NSW locations, quite small on average