Transport‐related carbon dioxide emissions: Energy pathways, decarbonization strategies, and public health implications

The transport sector contributes nearly 23% of global energy‐related carbon dioxide (CO 2 ) emissions and remains a major source of urban atmospheric burden. Although CO 2 is non‐toxic at ambient concentrations, it plays a critical role in climate forcing and indirectly alters air quality and human exposure patterns. This review presents an integrated framework linking transport‐related CO 2 emissions, real‐world driving variability, atmospheric processes, and public health outcomes. The review was developed through a structured narrative synthesis of literature from transportation engineering, climate science, and environmental health domains. A multi‐scale perspective is adopted to connect vehicle‐level emission metrics with urban microclimate dynamics and broader climate responses. Particular emphasis is placed on the discrepancy between laboratory certification cycles and real‐world driving conditions, which often leads to underestimation of on‐road CO 2 emissions and associated environmental impacts. The review further examines the influence of CO 2 ‐driven climate change on atmospheric conditions, including urban heat island intensification, boundary layer dynamics, and secondary pollutant formation. Three major climate‐mediated health pathways are discussed: thermal stress, aeroallergen enhancement, and vector‐borne disease expansion. Transport decarbonization strategies, including electrification, hydrogen‐based systems, efficiency optimization, active transport, and compact urban planning, are evaluated for their environmental and public health implications. Overall, the review highlights the need for integrated modeling frameworks that combine emission inventories, atmospheric processes, and exposure metrics to support sustainable transport systems and informed environmental decision‐making.