Carbonated recycled aggregate concrete (CRAC), which involves the recycling of concrete waste and fixing CO₂, is expected to achieve a good positive net CO₂ benefit. Unfortunately, the existing studies imply that the application of recycled aggregates and carbonation modification have both advantages and disadvantages in producing a net climate benefit. To explore the net CO₂ benefit of CRAC, the life-cycle CO₂ emissions of recycled aggregate concrete (RAC) and CRAC are calculated considering the uncertainty of CO₂ emissions from material production. Three different scenarios are analyzed: transporting CO₂ through pipelines, producing recycled concrete on site, and using clean-energy transportation. Based on the analyzed data, a machine learning model is well trained and can be used to efficiently pre-estimate the possibility of a positive net CO₂ benefit of RAC/CRAC in practical engineering design. Based on the analysis results, the authors suggest the adoption of high-efficiency carbonation treatment on recycled aggregates, specifically when the CO₂ curing duration is less than 48 h and the strength ratio is greater than 0.95. The combination of clean-energy transportation and high-efficiency carbonized recycled aggregates is a promising path to achieve good life-cycle CO₂ benefits in the construction industry.