<p>The polymer industry is confronting an urgent sustainability trilemma: accelerating plastic pollution, substantial CO₂ emissions from production processes, and dependence on diminishing fossil resources. Upcycling CO₂ into polymers presents a promising solution to these interconnected issues; however, existing CO₂-to-polymer technologies face significant challenges: dependence on concentrated CO₂ sources rather than direct air capture (DAC), reliance on complex catalysts and energy-intensive conditions (elevated temperatures/pressures), and generation of polymers with limited self-healing and recyclability. Herein, we propose a catalyst-free strategy of converting atmospheric CO₂ into carbonate ions (CO₃^2-) as intermediates for the synthesis of dynamic covalent polymers. This approach is based on a dynamic bond system, termed the CO₃^2--bridged dynamic covalent bond, enabling catalyst-free synthesis of polymers from ambient air at room temperature and pressure. The resultant polymers show excellent mechanical properties, rapid self-healing, and versatile circularity through three distinct pathways: thermal reprocessing, closed-loop chemical recycling via acid-triggered depolymerization at room temperature, and upcycling of mixed CO₂-derived polymers into hybrid materials with enhanced properties. This study provides a platform for both low-energy-consuming CO₂ valorization and the development of sustainable polymers.</p>