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Australia's wheat belt is bracing for profound shifts as climate change accelerates.
North-West Victoria emerges as ground zero, with models forecasting up to 27 per cent yield losses under hotter, drier conditions likely by mid-century.1
State-wide, wheat production could drop 14 per cent, driven by rising temperatures and falling rainfall during critical growth phases.1
Southern cropping zones suffer most from prolonged droughts and heatwaves, while northern areas grapple with erratic rains.
Advanced simulations using APSIM and IPCC scenarios reveal stark declines across grains like barley and canola too.
Extreme heat days scorch crops, pests invade new territories, and seasonal windows narrow, squeezing farmers' margins.
ABARES reports highlight recent volatility, with 2025-26 forecasts hinging on elusive spring rains.6
Yet adaptation offers hope: drought-tolerant varieties and precise sowing could blunt the edge.
Policymakers face urgent calls to bolster regional resilience amid high-emissions pathways.
This investigation draws on peer-reviewed models and government data to map the risks ahead.
Regions at Risk
North-West Victoria stands out as the epicentre of projected crop declines.
Models predict 27 per cent wheat yield losses here under the IPCC's hotter-and-drier scenario by 2036-2065.1
Lower baseline rainfall exacerbates vulnerabilities during reproductive and grain-filling stages.
The broader Victorian wheat belt could see 14 per cent drops, as high temperatures overwhelm rain-fed systems.1
Southern Australia, including parts of New South Wales and South Australia, faces intensified droughts and aridity.11
IPCC projections confirm south-west rainfall very likely to decrease under all scenarios.11
Northern regions like Queensland encounter heavier floods but risk heat stress on sorghum and cotton.4
Yield Projections by Crop
Wheat yields in Victoria plummet most severely, with medium-term losses tied to emissions pathways.
Under RCP8.5 hotter-drier conditions, North-West Victoria wheat falls 27 per cent by 2036-2065; state-wide 14 per cent.1
Short-term (2016-2045) declines hover lower at around 10-15 per cent across scenarios, per APSIM simulations.2
Barley and canola, simulated via APSIM across 3000-plus stations, face similar rainfall-driven drops in southern belts.2
Sorghum in Queensland's Darling Downs holds steadier short-term but risks 20 per cent medium-term under high heat.6
Corn and cotton endure pest surges and moisture deficits, with vegetables wilting under heatwaves.4
ABARES notes 2025-26 wheat at 30.6 million tonnes nationally, but warns of spring frost and drought risks.11
Key Climate Drivers
Temperatures climb 1.4 degrees Celsius across Australian land since 1910, intensifying heat extremes.11
High degree-days above 29 degrees Celsius slash yields during grain filling, partially offset by rain.1
Rainfall variability worsens: south-west cools-season cuts heighten soil moisture deficits.11
Extreme heat days proliferate, wilting crops like tomatoes and berries.4
Pest pressures mount as fall armyworm spreads southwards with warming.14
Diseases thrive in humid extremes, while frost lingers as a reproductive-phase threat.1
Shifts in Seasons
Cropping windows compress as sowing rains arrive later amid autumn dryness.11
Short-term: delayed wheat sowing north of Dubbo to July if rains fail.2
Medium-term: heat hastens maturation, risking terminal drought.1
Long-term under SSP5-8.5: fire weather extends, squeezing harvest slots.11
Vegetative phases shorten, curbing biomass buildup.
Data Sources and Models
APSIM drives simulations for wheat, barley, canola, sorghum across thousands of stations.2
CMIP6 under SSP2-4.5 (medium) and SSP5-8.5 (high) informs IPCC regional factsheets.11
Bureau of Meteorology supplies daily grids for temperature, rainfall exposures.1
ABARES crop reports track real-time yields, like 2025-26 forecasts.6
DSSAT offers comparative validation, though APSIM excels in arid simulations.3
Uncertainties and Gaps
Model ensembles yield wide yield ranges, especially above two degrees warming.7
Temperature responses vary across 29 wheat models, inflating projections.7
Adaptation unaccounted: tech lifts productivity 68 per cent since 1989 despite climate.12
Pest expansions poorly quantified beyond armyworm cases.
Long-term gaps persist in vegetable, cotton under high-emissions.
Adaptation Strategies
North-West Victoria farmers should prioritise heat-tolerant wheat varieties.
Shift sowing to capture residual moisture, per APSIM rules.2
Southern zones invest in soil management to retain fallow rains.
Government fund insurance against volatility, per ABARES insights.12
National R&D targets pest monitoring, resilient canola for NSW-SA.
Integrated planning blends mitigation with extension services for real-time forecasts.
References
- Impact of climate change on agriculture in Australia: an interactive fixed effects model approach
- Methodology – Yield Gap Australia
- APSIM and DSSAT models as decision support tools
- Agricultural Impacts: How Climate Change is Altering the Australian Food Landscape
- Australian Crop Report September 2025
- The uncertainty of crop yield projections is reduced by...
- Regional fact sheet - Australasia
- ABARES says changing climate is costing every farm
- Climate change's effects on farming and agriculture