Due to the continuous increase in fuel consumption in the transportation sector and the related environmental issues, such as climate change and energy depletion, there is a pressing need to research, develop, and implement more sustainable modes of transportation. This study assesses the expected environmental implications of the penetration of electric motorcycles in the Australian market. For this purpose, the total greenhouse gas (GHG) emissions to be produced by motorcycles during the next 15 years were determined by developing relevant ARIMA and exponential smoothing prediction models and using different scenarios (25%, 50%, 75%, and 100% electric motorcycles penetration). Moreover, this study considered the future contribution of renewable energy to electricity sources. The results showed that the continuous dependence on the internal combustion engine motorcycle (ICEM), as a two-wheeled mode of transportation, can lead to a considerable increase in GHG emissions and fossil fuel consumption in the long term, and in this case, the expected increase in GHG emissions could be around 40% from 2020–2040. Meanwhile, the partial substitution of ICEMs with electric motorcycles at a percentage of more than 25% by 2040 could lead to substantial GHG emissions reductions. With EM penetration rates of 50% and 75%, the corresponding fall in GHG emissions would be 44.56% and 66.84%, respectively. Meanwhile, a complete replacement of ICEMs with electric motorcycles could lead to an 89.12% reduction in GHG emissions by 2040.