The “Father of Our National Park System,” John Muir was an influential writer, naturalist, and conservationist during the late 19th and early 20th centuries. Born in 1838 in Dunbar, Scotland, he emigrated to the United States with his family and was captivated by the land. He was a prize-winning inventor, but it’s his love for wild places and absolute dedication to protecting them that we remember him for.

As a young man, he explored the North American continent by foot, walking thousands of miles until he eventually settled in California. There, he fell in love with Yosemite Valley and the Sierra Nevada Mountains.His article series, “Studies in the Sierra,” put his name on the map and launched a prolific writing career, with over 300 articles and 10 books published. A true mountain man, he encouraged everyone to “climb the mountains and get their good tidings”.

His writings inspired presidents, congressmen, and average citizens to care about nature. In 1890, due in large part to a series of articles he published in Century magazine, U.S. Congress created Yosemite National Park. Muir was also involved in the creation of the Sequoia, Mount Rainier, Petrified Forest, and Grand Canyon National Parks, thus earning his title.

But his work didn’t stop there: in 1892, Muir and his supporters founded the Sierra Club to “do something for wildness and make the mountains glad.” In 1901, he published the book “Our National Parks” and caught the attention of President Theodore Roosevelt, who visited him at Yosemite. During that visit, they laid the foundation of Roosevelt’s groundbreaking conservation programs.

Under his direction, the Sierra Club fought fiercely to protect Yosemite and the Sierra Nevada, but in 1913, the Hetch Hetchy Valley was dammed to secure drinking water for San Francisco. Muir died one year later, but his memory lives on, continuing to inspire new generations of conservationists and environmental activists everywhere. 

A prolific writer, scientist, and ecologist, Rachel Carson sparked a movement with her 1962 book, Silent Spring. Disturbed by the widespread use of chemical pesticides after World War II, she warned the pubic about the dangers and long-term effects of this practice. Challenging agricultural scientists and the U.S. government, she was attacked by government officials and the chemical industry, but never backed down.

Having served as a scientist and editor for the U.S. Fish and Wildlife Service for 15 years, she was uniquely qualified to sound the alarm. In 1963, she testified before Congress, calling for new policies to protect human health and the environment. She died of breast cancer just 1 year later.

Although she is best known for writing Silent Spring and inspiring the first Earth Day, Carson spent decades researching and writing about the environment before creating her pinnacle book. Her work continues to inspire new generations of citizens to protect the planet and everyone that lives here.

An award winning broadcaster, writer, and naturalist, Sir David Attenborough has inspired millions to connect with and care about nature.In 1954, he collaborated with reptile curator Jack Lester to create the popular TV series Zoo Quest, filming live animals in the wild and in zoos.In 1965, he became controller of BBC-2, launching a variety of productions ranging from Jacob Bronowski’s The Ascent of Man to Monty Python’s Flying Circus.In 1968, he was promoted to director of the BBC’s TV programming but resigned just 4 years later to start his freelance career.Freed from the constraints of working for a TV network, he wrote and narrated several award-winning programs, including the 9-part Life Series, The Blue Planet, State of the Planet, Are We Changing Planet Earth?, and Climate Change— The Facts.Through his work, he has brought environmental issues to the forefront, warning a failure to act on climate change could lead to “the collapse of our societies”. More recently, he narrated Blue Planet II and the 8-part Our Planet Series, and met with President Barack Obama to discuss climate change. At 93 years old, he continues to work and inspire viewers all over the world.

One of the most powerful voices in the history of American conservation, Theodore Roosevelt spent his childhood hiking, rowing, swimming, riding, bird-watching, hunting, and compiling a massive taxidermy collection.

A bookish and sickly child, he nonetheless couldn’t be kept away from his true love: the great outdoors.When he became president in 1901, he acted on that passion, establishing 150 national forests, 51 federal bird reserves, 4 national game preserves, 5 national parks, and 18 national monuments on over 230 million acres of public land and signing the 1906 American Antiquities Act.

A true advocate for the environment, he felt that “The nation behaves well if it treats the natural resources as assets which it must turn over to the next generation increased and not impaired in value.” In 1905, he established the United States Forest Service to manage the 150 million acres of land that were set aside as National Forests.

His Federal Bird Reserves eventually became today’s national wildlife refuges, which are managed by the United States Fish and Wildlife Service.While he didn’t establish the National Park Service (that was signed into law by President Woodrow Wilson, 7 years after he left office), he did establish 23 parks and monuments during his tenure. The first president of the 20th century, he set an important precedent by refusing to exploit the environment for personal gain.

When Congress fought his efforts to establish Grand Canyon National Park, Roosevelt used his executive power to protect it as a National Monument instead, imploring them to “keep this great wonder of nature as it now is. I hope you will not have a building of any kind, not a summer cottage, a hotel, or anything else, to mar the wonderful grandeur, the sublimity, the great loneliness and beauty of the canyon. Leave it as it is. You cannot improve on it. The ages have been work on it, and man can only mar it.”

An avid hunter, he earned his nickname “Teddy” while hunting in Mississippi. While there, his hunting party cornered a Louisiana Black Bear and tied it to a willow tree, urging the president to shoot it. Offended by this lack of sportsmanship, Roosevelt refused to kill the bear.

When political cartoonist Clifford Berryman heard the story, he scrambled to draw a cartoon celebrating the President’s decision. When he saw the cartoon, Brooklyn candy shop owner Morris Michtom created a stuffed toy bear and dedicated it to Roosevelt, calling it Teddy’s Bear. The name stuck and children have been cuddling teddy bears ever since.

A conservationist to the core, he mused that “we have become great because of the lavish use of our resources. But the time has come to inquire seriously what will happen when our forests are gone, when the coal, the iron, the oil, and the gas are exhausted, when the soils have still further impoverished and wash into the streams, polluting the rivers, denuding the fields, and obstructing navigation.”

U.S. senator, lawyer, WWII veteran, and champion of environmental causes Gaylord Nelson conceived the idea of Earth Day, which American Heritage Magazine called “one of the most remarkable happenings in the history of democracy.”

The son of a country doctor, Nelson began his political career in 1948, starting as the Dane Country state senator and then moving on to become the governor of WI. During this time, he created Wisconsin’s Outdoor Recreation Acquisition Program, which funded the purchase of 1 million acres of park land.

In 1962, he was elected to the U.S. senate and represented WI for 18 years. While there, he quickly established himself as a trailblazer, authoring legislation to create a national hiking trail network and helping to preserve the 2,100-mile Appalachian Trail. He also sponsored several important pieces of environmental legislation, including the Wilderness Act, the Alaska National Interest Lands Conservation Act, and the National Environmental Education Act.

The senator also helped create the St. Croix Wild and Scenic Riverway and the Apostle Islands National Lakeshore, and established the Upper Great Lakes Regional Commission and Operation Mainstream/Green Thumb, a program that employed the elderly in conservation projects.)

In a 1963 letter to President John F. Kennedy, he wrote that “There is no domestic issue more important to America in the long run than the conservation and proper use of our natural resources, including fresh water, clean air, tillable soil, forests, wilderness, habitat for wildlife, minerals, and recreational assets.”

What he is best known for, however, is conceiving the idea of Earth Day. In 1969, he traveled to California to speak at a water conference and saw for himself the damage from the Santa Barbara oil spill, calling it “a horrible scene.” While flying home, he read a magazine article about the college campus teach-ins of the Vietnam War era, and was struck by an idea: “Why don’t we have a nationwide teach-in on the environment?” Earth Day was an instant success, drawing 20 million participants in the first year. Over 2,200 colleges marked the occasion and Congress adjourned so that its members could speak to their constituents across the nation. And his efforts laid the foundation for groundbreaking laws like the Environmental Protection Act, the Clean Air Act, and the Clean Water Act.

After leaving senate in 1981, he served on the board of The Wilderness Society, as Chairman of the Earth Day XXV celebrations, and started the Earth Day Network’s Clean Energy Now! campaign. In honor of his efforts, he received the Ansel Adams Conservation Award, the UN Environment Programme’s Only One World Award, and the Presidential Medal of Freedom. In 2002, the University of Wisconsin-Madison’s Institute for Environmental Studies was renamed in his honor, and in 2004 the Gaylord A. Nelson Wilderness was designated in WI. One year later, he died of cardiovascular failure. But from the continued prevalence of Earth Day to the powerful legislation he crafted and backed, his legacy lives on.

Scientist, broadcaster, author, and environmental activist David Suzuki has a knack for explaining scientific and environmental issues to the public in a relatable way. Best known for his epic series “The Nature of Things with David Suzuki,” he’s a third-generation Japanese Canadian who feels a deep connection to the environment and keenly understands the plight of marginalized people.

With the end of the war, the Suzukis were barred from returning to their home, so they resettled in Ontario. There, David’s love for nature really developed, as he explored and collected specimens in a swamp near his home. As a young man, he studied in the U.S., eventually earning his Ph.D. in Zoology from the University of Chicago.After graduating.

While there, he was appalled by the treatment of African Americans and joined the local NAACP chapter, becoming the first non-black person to do so. Eventually, he returned to Canada, teaching Genetics at the University of Alberta and then Zoology at the University of British Columbia, spending 38 years there. 

A talented scientist, Suzuki spent years researching fruit fly genetics and became world-renowned for his work, receiving the Steacie Memorial Fellowship in 1969 for being the best young Canadian Scientist. He even authored a textbook on the subject, “An Introduction to Genetic Analysis,” which is still widely used in the U.S.Despite his talent for research, Suzuki felt that he could better serve by communicating his scientific findings and concerns with the public, appearing on several TV shows. He also created and hosted several TV specials. Although Suzuki spent much of his career in front of cameras, he actually prefers the radio. In 1989, his award-winning CBC radio show “It’s a Matter of Survival” sounded a worldwide alarm on climate change. In addition to his broadcasting career, Suzuki is a prolific writer and has published hundreds of articles, maintained several regular newspaper columns, and published more than 50 books, including an autobiography and several children’s books.

Always an outspoken advocate for the environment, he cofounded the David Suzuki Foundation in 1990 with the aim of promoting environmental conservation by providing research and information to the government, businesses, and individuals. In the late 20th century, he was one of the first major voices to sound the alarm and call for action on the threat of global warming.

He also launched the Blue Dot movement to bring attention to the fact that Canada doesn’t recognize the right to live in a healthy environment, and has a long history of involvement with groups like the Canadian Civil Liberties Association and Amnesty International.

Today, he has significantly cut down on travel in an effort to reduce his carbon footprint. He has received several awards for his work, including the UN Environment Programme Medal in 1985, UNESCO’s Kalinga Prize for the Popularization of Science in 1986, and the Right Livelihood Award in 2009. He was made an officer of the Order of Canada in 1977, and given its highest honor, a Companion of the Order, in 2006. He ranked fifth in CBC TV’s “The Greatest Canadian” competition, and has two schools named after him. And because of his vocal support of First Nations people, he has been honored and formally adopted by several indigenous groups.

At 84 years old, he continues to be an outspoken eco-warrior and truth-teller, sharing that "as an elder, I'm no longer subject to worrying about getting a job, or getting fired...so I can speak the truth from my heart."

English Primatologist, ethologist, and anthropologist, Dr. Jane Goodall is best known for her 45 year study of the social and family lives of Chimpanzees. Through her research, she discovered that Chimpanzees make tools, hunt cooperatively, eat meat, wage war, have strong mother/infant bonds, and show acts of compassion. And when she reported her findings, she upended every conceptual line we had drawn between us and other animals.

Thanks to her groundbreaking, immersive approach to research, she observed what no other scientist had before. In 1963, her discoveries were shared with the world via the National Geographic article “My Life Among the Wild Chimpanzees.” Two years later, NatGeo released “Miss Goodall,” following Jane as she worked.

In 1977, she founded the Jane Goodall Institute, thus beginning her shift from research to science-based activism. 5 years later, she founded Roots and Shoots, a network of young people who share Jane’s conservation ethic and are working to make the world a better place.

That same year, she also founded JGI’s Tchimpounga Sanctuary to provide a home for chimpanzees orphaned by the illegal bushmeat and pet trades. Today, over 150 chimpanzees live there. In 2004, she was named a UN Messenger of Peace for her Roots & Shoots program. Through her work, Goodall has redefined species conservation and changed the way we view ourselves forever.

Today, she travels the world, speaking about the environmental crisis and the unique threats facing chimpanzees. And she’s still making headlines—in January of this year, she committed to planting 5 million trees in 2020!

Known by most as the laid back, fun-loving “Crocodile Hunter,” Steve Irwin was a wildlife expert and conservation enthusiast who truly loved the animals he worked with. Growing up at the zoo that his parents owned and operated, Irwin was captivated by wildlife from the start—and he certainly had a knack for it.

By 6 years old, he had already caught his first venomous snake and started helping his father catch crocodiles when he was just 9. In the 1980s, he spent time in the remote area of North Queensland, developing new techniques to catch and manage crocodiles.

He married his wife, Terri, in 1992 and, in lieu of a honeymoon, they filmed a wildlife documentary that was later turned into the beloved series “The Crocodile Hunter.” Throughout his tenure on the show, Irwin inspired and educated millions of viewers with his knowledge and enthusiasm for Australia’s unique wildlife.

After his tragic 2006 death, his family carried on his legacy and have realized his dream of fueling conservation efforts around the world. The Australia Zoo’s Wildlife Warriers program, which was founded by Steve and Terri, aims “to be the most effective wildlife conservation organization in the world through the delivery of outstanding outcome-based programs and projects, inclusive of humanity.”

At home on their Wildlife Reserve, the Irwin family continues to educate people about wildlife and the importance of conservation, proving that his life, though short, was not wasted. In Steve’s words, “If we save our wild places, we will ultimately save ourselves.”

2004 Nobel Peace Prize Laureate, founder of the Green Belt Movement, and author of 4 books, Wangari Muta Maathai was born in 1940 in rural Kenya. From a young age, she showed grit and determination, eventually becoming the first woman in East and Central Africa to earn her doctorate degree.Around the same time, she also became the first woman to chair The University of Nairobi’s Department of Veterinary Anatomy. Active in the National Council of Women in Kenya, she served as its chairman from 1981-1987 and introduced the idea of community-based tree planting.Focused on reducing poverty and conserving the environment via planting trees, she eventually founded the Green Belt Movement. Respected for her work in service of democracy, human rights, and environmental conservation, Maathai overcame incredible odds to change thousands of lives and become an international inspiration. She addressed the UN several times, speaking on behalf of women during the 5-year review of the Earth Summit and serving on the Commission for Global Governance and the Commission on the Future.A true barrier-breaker, she also served in the Kenyan government in many capacities and was named a UN Messenger of Peace in December 2009. In 2010, she was appointed to the Millennium Development Goals Advocacy Group and the Karura Forest Environmental Education Trust. That same year, she founded the Wangari Maathai Institute for Peace and Environmental Studies in partnership with the University of Nairobi. Just one year later, she passed away after a battle with ovarian cancer. Her work continues to inspire and uplift women everywhere.

The Father of Wildlife Ecology and the U.S. wilderness system, Leopold was a conservationist, forester, philosopher, educator, writer, and outdoor enthusiast. A 1909 graduate of the Yale Forest School, he spent much of his young life observing, journaling, and sketching nature and eagerly pursued a career within the newly established United States Forest Service.

Within just a few years of working in Arizona and New Mexico’s National Forests, he was promoted to the position of supervisor of the Carson National Forest in New Mexico. In 1924, he was instrumental in an effort to turn the Gila National Forest into the nation’s first wilderness area. That same year, he was transferred to Madison, WI and continued to investigate ecology and conservation philosophy, publishing his first wildlife management textbook in 1933. In 1935, Leopold and his family began experimenting in ecological restoration at a worn-out farm along the Wisconsin River, planting thousands of pine trees and restoring prairies there.

He wrote extensively about what he learned and saw at “the Shack.” He died of a heart attack on April 21, 1948, just one week after learning that his prolific book, “A Sand County Almanac,” would be published. With over 2 million copies in print, it remains one of the most respected and influential books about the environment.

Of course, we can’t talk about environmental heroes without mentioning Greta Thunberg. Lone protestor turned leader of the historical Fridays for the Future movement, Thunberg has inspired millions of people around the world to voice their concerns about climate change.

Rising above attacks from high and low, she has emerged to give a voice to those that are often referenced but rarely listened to when it comes to climate change: children. In 2019, she was named Time Magazine’s Person of the Year, a winner of the 2019 Right Livelihood Award in Sweden, and was nominated for the Nobel Peace Prize.

From the U.N. Climate Summit to the steps of the White House to the chambers of U.S. Congress and the World Economic Forum, Thunberg speaks truth to power everywhere she goes—and we don’t think she’ll be going away any time soon.