Agentic AI Systems: A Review of Architectures, Autonomy, and Ethical Implications

Artificial Intelligence (AI) is a new revolution in the development of intelligent systems, which enables the machine to perceive, reason, and take intelligent actions without much human interference. This review attempts to explore architecture principles, autonomy models, ethical concerns and application of agentic AI in terms of its potential to deliver environmental sustainability. It highlights the transition towards architectures based on advanced cognitive, modular, reinforcement learning-based, and Hybrid systems and points out the fact that these systems are able to be more flexible, scalable and make better decisions. The review explains how agentic AI has been used in climatic modelling, biodiversity monitoring, intelligent agriculture, sustainable cities, and disaster response and demonstrates how the technology has the capability of unleashing data driven ecological decision-making. Moreover, it takes care of governance, like accountability, transparency, and value alignment issues, peripheral to the prudent application of such technologies to ecologically fragile zones. Finally, the article even provides some critical paths to go in the future such as scalability of computations, reliability, explicability, and even ethical questions in critical contexts, but rather proposes future tracks in human ai cooperation, policy relations, and even sustainable invention. The agentic AI is a revolutionary force that could help in reducing the threat of the climatic predicament, resource management as well as environmental conservation within the global ecosystem through the incorporation of the technological advancement with environmental stewardship. This review points at the explosion of agentic AI in confronting environmental decision-making, climate sustainability, and ecological resilience.