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1780s Thomas Malthus
1890 U.S. Government declares frontier closed
1891 Forest Reserve Act (1891)
1892 John Muir (1892), preservationist
1892 Sierra Club
1900 Lacey Act (1900)
1900-1909 Theodore “Teddy” Roosevelt (early 1901-1909 The Golden Age of Conservation)
1902 Reclamation Act (1902)
1905 Audobon Society, founding of (1905)
1905 Gifford Pinchot (1905)
1906 Antiquities Act (1906)
1908 Svante Arhenius (1908)
1910 Alice Hamilton (1910?)
1916 Woodrow Wilson and National Park Service Act (1916)
1918 Migratory Bird Treaty Act (1918)
1930s Franklin D. Roosevelt (early 1930s stuff … think history class!)
1933 Civilian Conservation Corps (1933)
1933 Tennessee Valley Authority (1933?)
1934 Dust Bowl begins in Midwest (1934)
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1968 Paul Ehrlich (1968)
Paul Ralph Ehlrich
WHAT DID HE DO?
Paul Ralph Ehlrich was famous for his warnings about exponential population growth and limited resources. However, Ehlrich was most famous for helping create the formula used to determine the human impact on a society, commonly expressed I=PAT, such that Human Impact (I) on environment equals the product of Population (P), Affluence (A) and Technology (T). This formula is very commonly used by environmental scientists all over the world to find the human impact.
WHEN DID HE DO IT?
The equation was developed in the 1970's during a debate between Barry Commoner, Paul R. Ehlrich and John Holdren regarding population growth. Commoner argued that human impact on the environment was caused primarily by changes in it production technology following World War II, while Ehlrich argued that all three elements, population, affluence and technology, were important and emphasized in particular the role of population growth.
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