How to sustain our world for future generations has perplexed us for centuries. We have reached a crossroads: we may choose the rocky path of responsibility or continue on the paved road of excess that promises hardship for our progeny. Independent efforts to resolve isolated issues are inadequate. Different from these efforts and from other books on the topic, this book uses systems thinking to understand the dominant forces that are shaping our hope for sustainability. It first describes a mental model, the bubble that holds our beliefs - that emerges from preponderant world views and explains current global trends. The model emphasizes economic growth and drives behavior toward short-term and self-motivated outcomes that thwart sustainability. The book then weaves statistical trends into a system diagram and shows how the economic, environmental, and societal contributors of sustainability interact. From this holistic perspective, it finds leverage points where actions can be most effective and combines eight areas of intervention into an integrated plan. By emphasizing both individual and collective actions, it addresses the conundrum of how to blend human nature with sustainability. Finally, it identifies primary three lessons we can learn by applying systems thinking to sustainability. Its metaphor-rich and accessible style makes the complex topic approachable and allows the reader to appreciate the intricate balance required to sustain life on earth.