Landfilling remains the dominant waste disposal method worldwide, particularly in developing countries, posing serious environmental, health, and climate challenges. Inefficient practices, weak regulations, and un-engineered sites contribute to massive greenhouse gas (GHG) emissions and resource loss. Transitioning to a circular economy (CE) offers a transformative path for sustainable waste management. By closing material loops, recovering energy, urban mining, controlling emissions and CE strategies can convert traditional landfills into eco-efficient systems. The integration of artificial intelligence (AI) further enhances this transition, enabling real-time monitoring, predictive management, and optimized resource recovery, thereby maximizing environmental and economic benefits. This review presents a three-level CE framework at micro (individual organizations), meso (industrial networks), and macro (national and international) levels designed to extract maximum value from waste streams and mitigate climate impacts. The proposed strategies demonstrate the potential to drastically reduce GHG emissions, promote clean energy via waste-to-energy routes, and contribute to SDGs 7, 11, 12, 13 and 15. By combining technology, innovation, and strategic management, this work highlights how AI-driven CE approaches can transform landfills from environmental liabilities into engines of sustainability and climate action. In implementing CE strategies at various levels, various challenges including technological, socio-economic, ethical, policy-based, and unintended consequences are encountered which impact sustainability initiatives. This review comprehensively discusses challenges associated with CE implementation and identifies technological advancement, social awareness and data-driven AI/ML-based modeling which could ensure success in circularity and ultimately curb climate change impacts in the long term.

Synthesis of small-diameter (ca. 1 nm) single-walled carbon nanotubes (SWCNTs) is rare due to the difficulty in establishing appropriate catalysts and environments that favor the generation of such species. However, because of their auspicious and structure-tunable electrical and optical properties, this goal remains at the focal point of numerous researchers. The development of a low-cost technique to create such materials could eliminate the main bottleneck hindering their widespread application. In this work, this objective was ultimately achieved by means of the Plasma-Catalytic Pyrolysis (PCP) process. The application of a DC water-stabilized plasma hybrid (WSP-H) torch within an entrained-flow reactor facilitated the breakdown of methane in the presence of an FeO micropowder (50 µm) catalyst. Consequently, high-quality SWCNTs and hydrogen were produced at a relatively large scale. Characterization of the resulting SWCNTs by microscopy and spectroscopy confirmed that the produced SWCNTs exhibited a large degree of structural perfection.