Earth visionaries. Climate drivers. Believers. World in their Hands tells the stories of those who saw the importance of our natural world and dedicated their lives to its conservation, preservation, and protection in diverse and inspiring ways. These were tireless champions–thinkers, doers, and fighters who spoke up and took action long before it was fashionable, or critical. Thinkers such as Henry David Thoreau and Aldo Leopold ground us in their deeply rooted emotional and physical attachments to nature. Doers like Theodore Roosevelt, John Muir, and Rachel Carson include those who geared up and went out there to study, learn, record, report, and otherwise inspire the rest of the world. Fighters are the folks that got vocal, sometimes loudly, and stood their ground in the face of staunch adversity and resistance. Even at their own peril, they refused to abandon their commitment to saving a species or coveted piece of land. Taking the preservation of the natural world into their own hands, their efforts led to the founding of the National Park Service and the Wilderness Society, the establishment of the Wilderness Act, the preservation of untold millions of acres of land around the world, and countless other victories. Their inspiring stories evoke a deeper appreciation of nature in each of us; showing us where we’ve been, how far we’ve come, and what the road ahead will look like for the next generation of conservation crusaders, at a time when conservation, environmentalism, and action is more vital than ever.