In conceiving this manuscript, that explores the Evolution of International Environmental Law, Sustainability, and Justice," My impetus derives from the profound connection observed on the gravity and need to champion a greener legacy during my tenure as a legal practitioner and lecturer of law. The catalyst for this endeavor emanated from a genuine desire to document the intellectual discourses that transpired during the academic engagements with my students, particularly at Maasai Mara University located at the epicenter of The Great Mara Triangle an ecological marvel and the cornerstone of Kenya's renowned Wildebeest migration. The lamentable circumstances surrounding the destruction of the Mau forest and the vulnerable state of Kenya's indigenous communities in the wake of climate change have been instrumental in galvanizing my scholarly pursuits. This book, therefore, undertakes a meticulous reevaluation of international law, scrutinizing Kenya's alignment with the global community concerning the dynamic landscape of International Environmental Law. The book explores the relationship between the environment and the law, underscoring the critical imperative for environmental conservation. It examines the topography of international law, revealing its role as a steadfast guardian of our environment and examining its evolution, notably its impact on sustainable development. I have made an earnest endeavor to confront a pivotal theme - The concept of environmental justice. Specifically, delving into how legal frameworks can be transformative for marginalized communities, and how the intersectionality of environmental issues underscores the urgency of equitable solutions. The main theme of this book is an urgent call to action to seek a path towards harmony, where legal systems become catalysts for global environmental well-being, particularly championing the rights of impoverished communities and in this pursuit equitable justice, and a sustainable future for all.A central focus in this book is the critical role of public participation in shaping environmental policies. i have made an endeavor to explore case studies from around the world, illustrating the power of grassroots movements and citizen engagement in influencing legislative decisions. I have explored the intersection of law, governance, and public sentiment, emphasizing the need for a harmonious balance that reflects the diverse perspectives within society. Environmental impact assessment emerges as a pivotal tool in the book, I have dissected its significance in mitigating the consequences of human activities on ecosystems. Through detailed analyses of landmark projects and their environmental assessments, readers gain a profound understanding of the complexities involved in striking a balance between development and conservation. There is a chapter dedicated to chemical pollution and water pollution that unveils the hidden threats that jeopardize our ecosystems. It delves into the legal frameworks governing the use and disposal of hazardous chemicals, shedding light on the pressing need for stringent regulations. The exploration of water pollution takes readers on a global journey, uncovering the challenges faced by communities grappling with contaminated water sources and the legal remedies available to them. The heart of the book lies in its examination of international laws and conventions that transcend borders in addressing environmental issues. I have made an earnest effort to navigate the agreements, treaties, and accords designed to foster global cooperation in the face of climate change and ecological degradation. From the Kyoto Protocol to the Paris Agreement, readers gain insights into the evolution of international environmental governance as well as the disproportionate impact of climate change on vulnerable communities and advocates for a holistic approach that intertwines environmental sustainability with social responsibility.