Thomas Malthus

1776 - 1834

A British Economist who said, "Human population cannot continue to increase. Consequences will be war, famine, and pestilence.

John Muir

1838 - 1914

Founded Sierra Club in 1892; fought unsuccessfully to prevent the damming of the Hetch Hetchy Valleu in Yosemite National Park.

Paul Ehrlich

1854 - 1915

A biologist who published "The Population Bomb" in 1968; discussed overpopulation and food production issues for future generations.

Theodore Roosevelt

1858 - 1919

president of the United States from 1901 to 1909, well-known for his conservation efforts. He established the first National wildlife Refuge at Pelican ISland.

Gifford Pinchot

1865 - 1946

First chief of the United States Forest Service; advocated managing resources for multiple use using principles of sustainable yield.

Aldo Leopold

1887 - 1948

Wrote a "Sand Country Almanac" published a year after his death in 1948; promoted a "Land Ethic" in which humans are ethically responsible for saving as the protecters of nature.

Rachel Carson

1907 - 1964

Published "Silent Spring" in 1962; documented the environmental damage done by DDT and other pesticides. This book heightened public awareness at the start of the modern environmental movement.

Garrett Hardin

1915 - 2003

Published "The Tragedy of the Commons" in the journal "Science" in 1968; argued that rational people will exploit shared resources.

Frank Sherwood Rowland

1927 - 2012

IN 1974, determined that CFC's destroy stratospheric ozone.

E.O. Wilson


Biologist who co0coined, with Robert MacArthur, the theory of island biogeography, which identifies factors that regulates species richness on islands.

Wangari Maathai

1940 - 2011

Won the 2004 Nobel Peace Prize for "Green Belt" movement-planting trees in Kenya that provided food and fuel, and improved soil erosion and desertification.