As global challenges continue to intensify, the need for psychology to meaningfully engage with today's most serious problems has never been clearer. This book demonstrates how the discipline can answer this call to action. Written by leading scholars, it offers a clear and comprehensive presentation of the theories and research that contribute to solving our most serious everyday world issues. Chapters explore extremism, polarization, and conflict; environmental and economic deterioration; systemic obstacles to adaptation; football disorder; the influence of AI on young people; weaknesses in STEM education; and the collapse of effective communication and dialogue. Together, these contributions provide both depth and breadth, showing how psychological science can illuminate and address the most pressing global concerns. Unifying these diverse topics into a coherent whole, the volume is an indispensable resource for students, academics, and professionals committed to applying psychology where it matters most.