Environment Planet Earth 12 Environmentalists You Should Know By Marc Lallanilla University of Texas at Austin University of California, Berkley Marc Lallanilla is a sustainable living and green design expert. As a member of the Society of Environmental Journalists, he also covers science, health, and environmental topics. our editorial process Marc Lallanilla Updated November 15, 2019 Marco Bottigelli / Getty Images Share Twitter Pinterest Email Planet Earth Conservation Weather Outdoors Environmentalists have had a big impact on our lives, but most people can't name one famous environmentalist. Here's a list of 12 influential scientists, conservationists, ecologists, and other rabble-rousing leaders who have been central founders and builders of the green movement. John Muir, Naturalist and Writer MPI/String/Archive Photos/Getty Images John Muir (1838–1914) was born in Scotland and emigrated to Wisconsin as a young boy. His lifelong passion for hiking began as a young man when he hiked to the Gulf of Mexico. Muir spent much of his adult life wandering in—and fighting to preserve—the wilderness of the western United States, especially California. His tireless efforts led to the creation of Yosemite National Park, Sequoia National Park, and millions of other conservation areas. Muir was a strong influence on many leaders of his day, including Theodore Roosevelt. In 1892, Muir and others founded the Sierra Club "to make the mountains glad." Rachel Carson, Scientist and Author JHU Sheridan Libraries/Gado/ Getty Images Rachel Carson (1907–1964) is regarded by many as the founder of the modern environmental movement. Born in rural Pennsylvania, she went on to study biology at Johns Hopkins University and Woods Hole Marine Biological Laboratory. After working for the U.S. Fish and Wildlife Service, Carson published "The Sea Around Us" and other books. Her most famous work, however, was 1962's controversial "Silent Spring," in which she described the devastating effect that pesticides were having on the environment. Though pilloried by chemical companies and others, Carson's observations were proven correct, and pesticides like DDT were eventually banned. Edward Abbey, Author and Monkey-Wrencher Edward Abbey (1927–1989) was one of America's most dedicated—and most outrageous—environmentalists. Born in Pennsylvania, he is best known for his passionate defense of the deserts of America's Southwest. After working for the National Park Service in what is now Arches National Park in Utah, Abbey wrote "Desert Solitaire," one of the seminal works of the environmental movement. His later book, "The Monkey Wrench Gang," gained notoriety as an inspiration for the radical environmental group Earth First!—a group that has been accused of eco-sabotage by some, including many mainstream environmentalists. Aldo Leopold, Ecologist and Author Aldo Leopold (1887–1948) is considered by some to be the godfather of wilderness conservation and of modern ecologists. After studying forestry at Yale University, he worked for the U.S. Forest Service. Though he was originally asked to kill bears, cougars, and other predators on federal land because of demands of protesting local ranchers, he later adopted a more holistic approach to wilderness management. His best-known book, "A Sand County Almanac," remains one of the most eloquent pleas for the preservation of wilderness ever composed. Julia Hill, Environmental Activist Andrew Lichtenstein/Getty Images Julia "Butterfly" Hill (born 1974) is one of the most committed environmentalists alive today. After nearly dying in an auto accident in 1996, she dedicated her life to environmental causes. For almost two years, Hill lived in the branches of an ancient redwood tree (which she named Luna) in northern California to save it from being cut down. Her tree-sit became an international cause célèbre, and Hill remains involved in environmental and social causes. Henry David Thoreau, Author and Activist FPG/Getty Images Henry David Thoreau (1817–1862) was one of America's first philosopher-writer-activists, and he is still one of the most influential. In 1845, Thoreau—disillusioned with much of contemporary life—set out to live alone in a small house he built near the shore of Walden Pond in Massachusetts. The two years he spent living a life of utter simplicity was the inspiration for "Walden, or A Life in the Woods," a meditation on life and nature that is considered a must-read for all environmentalists. Thoreau also wrote an influential political piece called "Resistance to Civil Government (Civil Disobedience)" that outlined the moral bankruptcy of overbearing governments. Theodore Roosevelt, Politician and Conservationist NPS It might surprise some that a famed big-game hunter would make it onto a list of environmentalists, but Theodore Roosevelt (1858–1919) was one of the most active champions of wilderness preservation in history. As governor of New York, he outlawed the use of feathers as clothing adornment in order to prevent the slaughter of some birds. While president of the United States (1901–1909), Roosevelt set aside hundreds of millions of wilderness acres, actively pursued soil and water conservation, and created over 200 national forests, national monuments, national parks, and wildlife refuges. Gifford Pinchot, Forester and Conservationist Historical/Getty Images Gifford Pinchot (1865–1946) was the son of a timber baron who later regretted the damage he had done to America's forests. At his insistence, Pinchot studied forestry for many years and was appointed by President Grover Cleveland to develop a plan for managing America's western forests. That career continued when Theodore Roosevelt asked him to lead the U.S. Forest Service. His time in office was not without opposition, however. He publicly battled John Muir over the destruction of wilderness tracts like Hetch Hetchy in California, while also being condemned by timber companies for closing off land to their exploitation. Chico Mendes, Conservationist and Activist Alex Robinson/Getty Images Chico Mendes (1944–1988) is best known for his efforts at saving the rainforests of Brazil from logging and ranching activities. Mendes came from a family of rubber harvesters who supplemented their income by sustainably gathering nuts and other rainforest products. Alarmed at the devastation of the Amazon rainforest, he helped to ignite international support for its preservation. His activities, however, drew the ire of powerful ranching and timber interests —Mendes was murdered by cattle ranchers at age 44. Wangari Maathai, Political Activist and Environmentalist Wendy Stone / Getty Images Wangari Maathai (1940–2011) was an environmental and political activist in Kenya. After studying biology in the United States, she returned to Kenya to begin a career that combined environmental and social concerns. Maathai founded the Green Belt Movement in Africa and helped to plant over 30 million trees, providing jobs to the unemployed while also preventing soil erosion and securing firewood. She was appointed Assistant Minister in the Ministry for Environment and Natural Resources, and in 2004 Maathai was awarded the Nobel Peace Prize while continuing to fight for the rights of women, the politically oppressed, and the natural environment. Gaylord Nelson, Politician and Environmentalist No other name is more associated with Earth Day than that of Gaylord Nelson (1916–2005). After returning from World War II, Nelson began a career as a politician and environmental activist that was to last the rest of his life. As governor of Wisconsin, he created an Outdoor Recreation Acquisition Program that saved about one million acres of parkland. He was instrumental in the development of a national trails system (including the Appalachian Trail) and helped pass the Wilderness Act, the Clean Air Act, the Clean Water Act, and other landmark environmental legislation. He is perhaps best known as the founder of Earth Day, which has become an international celebration of all things environmental. David Brower, Environmental Activist Joe Munroe / Getty Images David Brower (1912–2000) has been associated with wilderness preservation since he began mountain climbing as a young man. Brower was appointed the Sierra Club's first executive director in 1952. Over the next 17 years, membership grew from 2,000 to 77,000, and the group won many environmental victories. His confrontational style, however, got Brower fired from the Sierra Club—he nonetheless went on to found the groups Friends of the Earth, the Earth Island Institute, and the League of Conservation Voters.