(Color Edition) The Frontier of Climate Science explores climate dynamics through physics, complex systems, and astronomy, synthesizing several decades of peer‑reviewed research. The book critically reviews the scientific foundations of modern climate theory, the evolution of IPCC assessments, and the limits of global climate models (GCMs) when confronted with observations. It investigates natural variability across multiple timescales, including oceanic oscillations, solar variability, and astronomical cycles driving both solar and climate variability, integrating satellite data, paleoclimate reconstructions, and empirical modeling approaches. From this evidence emerges a balanced view of climate risk, favoring pragmatic adaptation over narrowly defined policy pathways such as Net Zero. Rich in insights and analytical approaches, the book helps readers understand climate variability, assess risks, think critically, and explore key open questions in climate science. Endorsed by the International Association for Gondwana Research (IAGR) and by CERI - Sapienza University of Rome. Forewords by M. Santosh, A. Prestininzi and J. Curry.