Book excerpt: This book explores the key learning concepts for global leadership in the face of modern international health crises and argues the need for fundamental reform to governance paradigms, within the global security sphere and policymaking circles. Beginning with an analysis of the worldwide response to the COVID-19 pandemic, the book provides insights from evolution, history, and human behaviour to explain how our current leadership paradigms have contributed to today’s global health challenges and draws lessons for the much larger crisis of climate change with the threat of massive biodiversity collapse. The second part of the book outlines tangible solutions to transform leadership and policy to enhance global security for both people and the planet, with the aim of averting future pandemics and our planetary emergency. This book: Will be among the first published works to examine the international response to the COVID-19 pandemic, and draws valuable lessons for our climate crisis. Directly addresses the nexus between scientific advice and policymaking, highlighting recommendations for future leaders. Provides a bridge between public health, the environment, and leadership. This book will prove an insightful resource for current and future world leaders, politicians, and policymakers, as well as environmental and public health professional bodies, think tanks, and institutions shaping the next generation of leadership.