The data is still too centralized, there is no transparency, such platform prone to privacy issues and ecologically unfriendly practices. A sustainable and environmentally-respectful tourism occurs on a decentralized system architecture, the Sustainable Tourism Blockchain-based Travel System (STBTS) that combines the concept of Artificial Intelligence (AI), blockchain technology, Internet of Things (IoT), and zero-knowledge cryptography to allow secure, privacy-preserving, and sustainable tourism operations. There are six core modules in the system: Self-Sovereign Identity (SSI) framework, which uses zk-SNARK to respect the privacy of the user verification; federated AI layer, which provides the context-aware recommendations; Proof-of-Sustainable-Travel (PoST) engine, which issues the Green Travel Token (GTT) with non-linear reward logic; Decentralized Dispute Resolution (DDR) model, which introduces AI based arbitration and blockchain authenticated evidence; sustainable dynamic pricing (SDP) module, which is driven by demand Actual testing shows that 67% of the processing time is reduced, 92% of frauds can be detected, 50% increases in trust in user security, 35% of cost reduction, and up to 25 kg of average carbon offset per transaction. The system is also capable of providing dispute resolution automation of 85%, eco-discount fairness of 90%, and decentralized identity validation that accounts to 100% without the loss of performance. These findings render STBTS a strong, scalable, and eco-friendly model of the next-gen tourism infrastructures and sustainable blockchain ecosystems.