Introduction We are living in a new era. There is a growing consensus among scientists that we have entered into a period of time in which human activity is now the dominant force upon Earth. There are more of us than ever before--our population has more than quadrupled in the last century, from 1.8 billion in 1920 to nearly 8 billion today. The utilization of Earth's natural resources to support and power all of the systems and activities of civilization has dramatically changed its air, water, and land. We are beginning to see that there are consequences for all of our actions. This book provides a visual perspective of that story, with the hope it will lead to greater awareness, better decisions, and a more sustainable future. Since 2013, Overview has had the mission to inspire the Overview Effect--a feeling reported by astronauts who have had the opportunity to look back at Earth from outer space.

From this distant vantage point, they experience a sensation of overwhelming awe and amplified appreciation for the planet we call home. When seen from space, Earth and our civilization seem simultaneously intriguing and unfamiliar. The abstract shapes, colors, and patterns inspire wonder at the planet's natural beauty and the impressive scale of the things we have created here. If we use this vantage point over different periods of time, we have the ability to see how things change. The stories in this book combine the scale afforded by satellite and aerial photographs with the element of time. This offers a powerful medium to observe and understand the massive scope of change that has taken place recently on Earth. The rapid growth of our population and advancement of our technological capability have made modern civilization not only possible, but incredible. We live in the most resource-abundant time ever because of our ability to invent and support our growing needs and expectations.

And yet it seems we have not fully come to a consensus with how our actions are beginning to jeopardize the most essential element of human life--a healthy, stable planet. Simply put, our rapid growth and societal complexity has led to far-reaching exploitation of the planet's natural resources. The burning of fossil fuels for energy has released dangerous amounts of carbon dioxide into the atmosphere. Just as decades of scientific research predicted, the globe is indeed warming, and the climate is indeed showing signs of change. Despite all the evidence of our impact and its consequences staring back at us, there is reason to be optimistic. The same scientists who predicted and continue to monitor global climate change have made it clear that it is not too late to adopt solutions that can both support our species and move us toward a more harmonious relationship with the planet. The combination of collective action, thoughtful policies, and technological innovation has the power to move us in a better direction. All of these forces begin with, and are amplified by, awareness.

Understanding how our choices impact the planet is an essential step if we hope to change course. The images and stories in this book provide a framework for thinking about how we have already impacted the planet and what is to come. It is only with that knowledge that we can build a vibrant civilization that grows, adapts, and operates in balance with the natural systems of our one and only home.