After taking the time to learn about many theories of sustainability, the state of our environment, and the way our world functions, I wanted to create a book to explain some of these concepts to my designer peers. Citing scientists, designers, theorists, business thinkers, and systems strategists, the book provides a view of sustainability through three lenses: why the world needs our help, where designers fit as changemakers, and finally how we can use design to change the world.