The Age of Global Change provides an in-depth examination of the major forces reshaping societies in the twenty-first century, by referring to themes of demography, globalization, cultural change, inequality, governance, health, and sustainability. It highlights how rapid population growth, urbanization, migration, and shifts in religious and linguistic patterns are transforming the social fabric worldwide. At the same time, globalization has brought about profound cultural shifts, fostering individualism, gender equality, and diversity discourses, while also provoking nationalist and populist reactions. This book discusses the emergence of a global culture defined by hyperconnectivity, symbolic consumption, and the post-truth condition, alongside the rise of contested phenomena such as wokeism that reflect deeper struggles over identity and values. In international affairs, the book situates these changes within a broader geopolitical realignment, where the decline of Western dominance is matched by the ascent of multipolar power centers, particularly in Asia. Economic inequality and corporate concentration of power are shown to exacerbate global divides, fueled by financialization, tax evasion, and crony capitalism. Health and sustainability are positioned as defining challenges of the century. From pandemics to mental health crises, and from climate change to ecological degradation, these issues highlight the vulnerabilities and interdependencies of an interconnected world. The author argues that humanity is undergoing a paradoxical transformation, marked by both fragmentation and integration, the persistence of traditions amid modernization, and escalating risks accompanied by new possibilities. Ultimately, the century will be shaped not only by crises but also by opportunities for innovation, cultural synthesis, and collective action.