Environmental nonprofits include The Nature Conservancy, Sierra Club, Greenpeace, the World Wildlife Fund and the Humane Society. Each of these groups operates nationally and internationally to advocate for sustainable practices and ecological and wildlife preservation.
The Nature Conservancy is a million-member-strong organization, as of 2015, that works in every state in the United States and 35 countries. Established in 1951, the Conservancy notes that it protects land, waterways and wildlife habitats.
Since its founding in 1892, the Sierra Club has grown to more than 2 million members and contributors, as of 2015, according to the club's website. These individuals support the organization's mission to protect wilderness, air, water and endangered species, and reduce pollution from fossil fuels. Its efforts have been instrumental in the creation of such legislation as the Endangered Species Act.
Greenpeace considers itself a "campaigning organization" that uses political protest to call attention to environmental challenges and solutions, as stated on the group's website. This financially independent organization was founded in 1971 in response to nuclear tests being conducted off Alaska's coast. As of 2015, Greenpeace has more than 2.8 million members internationally.
Known for its iconic panda-bear logo, the World Wildlife Fund works throughout the United States and in 100 countries, the organization states in 2015. Its focus is science-based, and its mission is to protect both humans and wildlife, helping them live harmoniously with their environments.
The Humane Society protects animals against cruel practices, such as irresponsible breeding, fighting, large-scale farming, cruel or illegal trade and wide-scale slaughter. The organization also cares for thousands of animals annually through a network of sanctuaries and animal care centers.