The value of adapting to climate change in Australian wheat farm systems: farm to cross-regional scale

摘要: Wheat is one of the main grains produced across globe and wheat yields are sensitive to changes in climate. Australia a major exporter wheat, variations its national production influence trade supplies global markets. We evaluated effect climate change 2030 compared baseline period (1980–1999) by upscaling from farm level. gross margins under current projected climates were assessed using technology management practices then with ‘best adapted’ yield achieved adjustments planting date, nitrogen fertilizer, available cultivars for each region. For (1980–1999), there was potential gap modelled as optimized adaptation gave up scaled (tonne/ha) (AUD$/ha) 17% 33% above baseline, respectively. In at Australian wheatbelt level, impact decline 1%. 2030, simulated decrease 1% when existing but increase them 18% assuming optimal adaptation. Hence, nationally fully-adapted system, increased margin 0.3% fully adapted baseline. However, substantial regional variation median decreasing 55% sites. Full systems not expected, so this will remain an on-going challenge. be greater opportunity overall water use efficiencies belt, mostly resulting elevated atmospheric CO2 concentrations.