Achieving net zero transportation emissions requires energy efficiency improvements and shifts to less carbon-intensive travel. This article addresses the gap in Australian transportation research regarding the impact of shifting short commuting trips from cars to bicycles on greenhouse gas (GHG) emissions. We model potential emissions reduction at the suburb scale across Australia centering on scenarios of increasing mode shift towards bicycling. Results indicate if all short commute car trips (≤10 km) shift to bicycles, 3.4 million cars per day will no longer be used for commuting, leading to a reduction of up to 5.4% of car commuting GHG emissions. This study also identifies where such mode shifts would result in the highest emissions reductions. The magnitude and location of potential emissions reduction brings a new perspective to emissions reduction, transportation, and bicycle planning, suggesting mode shift to bicycling in areas with a high number of short car trips could reduce GHG emissions.