Green Consensus Mechanism for Sustainable Blockchain in Carbon-Neutral Smart Cities

Abstract

The rapid integration of blockchain technology into smart city infrastructure presents both transformative opportunities and environmental challenges. While blockchain enhances transparency, security, and decentralization, its conventional consensus mechanisms-particularly Proof of Work (PoW)-are energy-intensive and environmentally unsustainable. As cities worldwide move towards carbon neutrality, there is an urgent need for energy-efficient and environmentally aligned blockchain systems. This paper introduces a novel Green Consensus Mechanism (GCM) tailored for smart cities that optimizes energy use, reduces carbon emissions, and leverages renewable energy sources. Drawing on interdisciplinary insights from environmental science, distributed computing, and urban planning, the proposed GCM aligns blockchain operations with sustainability goals. Through simulations and comparative analysis against existing mechanisms such as Proof of Stake (PoS), Proof of Authority (PoA), and Delegated Proof of Stake (DPoS), this study demonstrates significant gains in energy efficiency and operational scalability. The results indicate that GCM can serve as a foundational layer for building carbonneutral smart cities while ensuring secure and decentralized digital governance.