Sustainable blockchain technology employs various methods to reduce energy usage and improve overall efficiency. This includes utilizing energy-efficient consensus mechanisms, such as Proof of Stake (PoS) instead of energy-intensive Proof of Work (PoW), as well as leveraging renewable energy sources and optimizing the blockchain architecture. The goal is not only to support the growing demand for blockchain applications but also to align with global efforts toward sustainability and climate change mitigation. Sustainable blockchains aim to maintain the benefits of decentralization without the high environmental costs often associated with traditional blockchain systems.