Earth3 is an initiative to make the real world fairer, more efficient and sustainable by creating a brand-new digital space. Its ultimate goal is to build a digital twin of the earth moderated by AI Agents. By harnessing the power of advanced Generative AI, alongside physical simulations (VR, AR), and renewable technologies, it aims to allow virtual space not only seamlessly intertwine with but enhance the reality. At present, Earth3 is building a decentralized AI ecosystem converging an AI Agent model layer that enables everyone to train, validate and share fruits in an AI-native era.