Sugarcane is one of the world’s main carbohydrates sources. We analysed the APSIM-Sugar (AS) and DSSAT/CANEGRO (DC) models to determine their structural differences, and how these differences affect their predictions of crop growth and production in Brazil. Both models initially underestimated leaf area index (LAI) and hence interception of solar radiation, although both well-predicted crop growth and production after calibration. The AS model under predicted yield at the hotter sites. Average predictions from both models of stalk yield and LAI resulted in closer predictions of the data than from the models individually. In response to elevated CO₂, both predicted higher yields, although increases with AS were greater than those with DC. AS showed higher sensitivity to rainfall reduction than DC, and DC showed higher sensitivity to temperature. Different models sensitivities to changed climate suggests the need of further studies on the crop physiology to reduce uncertainty about projected climate change.