Using producers’ own production and financial data from the Tumbarrumba 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 feeder steer enterprise 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 19% lower, average maximum temperature was 3% higher and pasture production 12% lower
- For 2030:
- The temperature increases are consistent (+10%) but the rainfall forecast is slightly variable ranging from a -6% to – 18%, and averaging a 12% reduction.
- This leads, on average, to an 8% decrease in annual pasture production and to maintain minimum ground cover a decrease in stocking rate will be required
- The trend across all models is for every month, except possibly November, to be drier.
- The greatest change (even more drier) is for the autumn and spring months.
- Less rain in April and May may affect the timing of the ‘autumn break’ for pasture growth.
- Less rain in spring may also act to shorten the growing season.
- All models predict a warmer trend throughout the year.
- The monthly median trend is for all months of the year to have warmer daily maximum and minimum temperatures, and possibly less frosts.
- Warmer temperatures are likely to increase winter pasture growth.
For more information, see the attached fact sheet.
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 Tumbarrumba, please click on: