Aldo Leopold (1887–1948)
1894 In The Mountains of California, Scottish–American naturalist John Muir describes his travels through wild places in California, evoking the deep spirituality and adventure he feels when in the wilderness.
1909 Gifford Pinchot’s The ABC of Conservation argues that future generations should be able to utilize Earth’s natural resources.
1968 US academic Paul R. Erlich and his wife, Anne, publish The Population Bomb, warning of the dangers of human population growth.
1970 On April 22, the first Earth Day is celebrated in the US. It becomes an annual global celebration of environmental ...