This textbook is intended to provide the core elements of a curriculum for teaching environmental science at the introductory level in Canadian colleges and universities. This book is suitable for students beginning a program in environmental science, environmental studies, or sustainability. It is also appropriate for arts students who require a science elective, and for science students who require a non-major elective. This book was written from the ground-up to provide Canadian information and examples. This national context is integrated throughout the text, along with North American and global data that provide a broader perspective.