This timeline of the history of environmentalism is a listing of events that have shaped humanity's perspective on the environment. This timeline includes human induced disasters, environmentalists that have had a positive influence, and environmental legislation.

For a list of geological and climatological events that have shaped human history see Timeline of environmental history and List of years in the environment.

7th century B.C. The Book of Deuteronomy in the Torah states: "When you besiege a city for a long time, making war against it in order to take it, you shall not destroy its trees by wielding an axe against them. You may eat from them, but you shall not cut them down. Are the trees in the field human, that they should be besieged by you?" The Book of Deuteronomy also emphasizes that individuals must take responsibility for their own waste to mitigate adverse human impacts on the environment: "Designate a place outside the camp where you can go to relieve yourself. As part of your equipment have something to dig with, and when you relieve yourself, dig a hole and cover up your excrement."

7th century 630s — Caliph Abu Bakr commanded his army: "Bring no harm to the trees, nor burn them with fire, especially those which are fruitful. Slay not any of the enemy's flock, save for your food." 676 — Cuthbert enacts protection legislation for birds on the Farne Islands (Northumberland, England).

9th–12th centuries Arabic medical treatises dealing with environmentalism or environmental science, including pollution, were written by Al-Kindi, Qusta ibn Luqa, Al-Razi, Ibn al-Jazzar, al-Tamimi, al-Masihi, Avicenna, Ali ibn Ridwan, Ibn Jumayʿ, Isaac Israeli ben Solomon, Abd-el-latif, Ibn al-Quff, and Ibn al-Nafis. Their works covered a number of subjects related to pollution, such as air pollution, water pollution, soil contamination, municipal solid waste mishandling, and environmental impact assessments of certain localities. Cordoba, Al-Andalus, had waste containers and waste disposal facilities for litter collection. William the Conqueror, a great lover of hunting, established the system of forest law. This operated outside the common law, and served to protect game animals and their forest habitat from destruction. In the year of his death, 1087, a poem, "The Rime of King William", inserted in the Peterborough Chronicle, expresses English indignation at the forest laws.

14th century 1306 — King Edward I of England bans the burning of sea-coal by proclamation in London, after its smoke had become a problem. 1366 — In september, the city of Paris forces butchers to dispose of animal wastes outside the city. 1388 — The English Parliament passes an act forbidding the throwing of filth and garbage into ditches, rivers and waters. The city of Cambridge also passes the first urban sanitary laws in England.

15th century 1420 to 1427, Madeira islands: destruction of the laurisilva forest, or the woods which once clothed the whole island when the Portuguese settlers decided to clear the land for farming by setting most of the island on fire. It is said that the fire burned for 7 years. 16th century

17th century

1609 — Hugo Grotius publishes Mare Liberum (The Free Sea) with arguments for the new principle that the sea was international territory free to use for seafaring trade. The ensuing debate had the British Empire and France claim sovereignty over territorial waters to the distance within which cannon range could effectively protect it, the three mile (5 km) limit. 1640 — Isaac Walton writes The Compleat Angler about fishing and conservation. 1664 — John Evelyn publishes one of the first texts on forestry, Sylva, or A Discourse of Forest-Trees and the Propagation of Timber in His Majesty's Dominions, in response to deforestation in England. 1690 — Colonial Governor William Penn requires Pennsylvania settlers to preserve of trees for every five acres cleared. — The last Mauritius dodo dies. The extinction was due to hunting, but also by the pigs, rats, dogs and cats brought to the island by settlers. Later the species has become an icon of animal extinction.

18th century

1710 — Jonathan Swift notes the contents of London's gutters: "sweepings from butchers' stalls, dung, guts and blood, drowned puppies, stinking sprats, all drenched in mud..." 1730 — In India, hundreds of Bishnois of Khejarli are killed trying to protect trees from Maharaja Abhai Singh of Marwar, who needed wood to fuel the lime kilns for cement to build his palace. This event has been considered as the origins of the 20th century Chipko movement. 1739 — Benjamin Franklin and neighbors petition Pennsylvania Assembly to stop waste dumping and remove tanneries from Philadelphia's commercial district. Foul smell, lower property values, disease and interference with fire fighting are cited. The industries complain that their rights are being violated, but Franklin argues for "public rights." Franklin and the environmentalists win a symbolic battle but the dumping goes on. 1748 — Jared Eliot, clergyman and physician, writes Essays on Field Husbandry in New England promoting soil conservation. 1762 to 1769 — Philadelphia committee led by Benjamin Franklin attempts to regulate waste disposal and water pollution. 1773 — William Bartram, (1739–1823). American naturalist sets out on a five-year journey through the US Southeast to describe wildlife and wilderness from Florida to the Mississippi. His book, Travels, is published in 1791 and becomes one of the early literary classics of the new United States of America. 1798 – Thomas Robert Malthus publishes An Essay on the Principle of Population, an evolutionary social theory of population dynamics as it had acted steadily throughout all previous history.

19th century

1820 — World human population reached 1 billion. 1828 — Carl Sprengel formulates the Law of the Minimum stating that economic growth is limited not by the total of resources available, but by the scarcest resource. 1828/1830- Thomas Carlyle introduces the use of the term "environment" in its modern sense. 1836 — Ralph Waldo Emerson publishes Nature. 1845 — First use of the term "carrying capacity" in a report by the US Secretary of State to the Senate. 1848 — Henry David Thoreau publishes Civil Disobedience. 1849 — Establishment of the U.S. Department of Interior. 1851 — Henry David Thoreau delivers an address to the Concord (Massachusetts) Lyceum declaring that "in Wildness is the preservation of the World." In 1863, this address is published posthumously as the essay "Walking" in Thoreau's Excursions. 1854 — Henry David Thoreau publishes Walden; or, Life in the Woods. 1859 — Publication of second edition of William Elliott's Carolina Sports by Land and Water (first published in 1846), an early example of the hunter-as-conservationist, a phenomenon which became increasingly important for conservationism. 1860 — Henry David Thoreau delivers an address to the Middlesex (Massachusetts) Agricultural Society, entitled "The Succession of Forest Trees," in which he analyzes aspects of what later came to be understood as forest ecology and urges farmers to plant trees in natural patterns of succession; the address is later published in (among other places) "Excursions", becoming perhaps his most influential ecological contribution to conservationist thought. 1862 — John Ruskin publishes Unto This Last, which contains a proto-environmental indictment of the effects of unrestricted industrial expansion on both human beings and the natural world. The book influences Mahatma Gandhi, William MorrisCoates, Peter. Nature: Western Attitudes Since Ancient Times. Polity Press, 1998. (Pg. 163). and Patrick Geddes.Boardman, Philip. The Worlds of Patrick Geddes. Routledge, 1978 (pg. 33). 1864 — George Perkins Marsh publishes Man and Nature (revised 1874 as The Earth as Modified by Human Action), the first systematic analysis of humanity's destructive impact on the natural environment and a work which becomes (in Lewis Mumford's words) "the fountain-head of the conservation movement." 1865 — William Stanley Jevons publishes The Coal Question raising concerns about the sustainability of coal energy. 1866 — The term ecology is coined in German as Oekologie by Ernst Haeckel (1834–1919) in his Generelle Morphologie der Organismen. Haeckel was an anatomist, zoologist, and field naturalist appointed professor of zoology at the Zoological Institute, Jena, in 1865. Haeckel was philosophically an enthusiastic Darwinian. Ecology is from the Greek oikos, meaning house or dwelling, and logos meaning discourse or the study of. — The American Society for the Prevention of Cruelty to Animals is founded. 1869 — Samuel Bowles publishes Our New West, an influential traveller's account of the wilds and peoples of the West, in which he advocates preservation of other scenic areas such as Niagara Falls and the Adirondacks. 1872 — The term acid rain is coined by Robert Angus Smith in the book Air and Rain. — World's first national park, Yellowstone National Park. — Arbor Day was founded by J. Sterling Morton of Nebraska City, Nebraska. It occurs every year on the last Friday in April in the US. 1873 — International Meteorological Organization is formed. 1873 — Friedrich Nietzsche develops the notion of a lifeless earth without redemption or replacement in his essay "On Truth and Lies in the Non-Moral Sense," and introduces the image of nature without humanity in a manner that not previously been made explicit. 1874 — Charles Hallock establishes Forest and Stream magazine sparking a US national debate about ethics and hunting. — German graduate student Othmar Zeidler first synthesises DDT, later to be used as an insecticide. 1876 — British River Pollution Control Act makes it illegal to dump sewage into a stream. 1879 — U.S. Geological Survey formed. John Wesley Powell, explorer of the Colorado River a decade earlier, will become its head in March 1881. 1883 — Francis Galton coins the still controversial concept of eugenics in his book Inquiries into Human Faculty and Its Development. 1889 — The Extermination of the American Bison by William Temple Hornaday, described by a contemporary scholar as the first important text of the American wildlife conservation movement, is published. The book argues for the protection of the small number of bison in Yellowstone National Park. 1890 — Yosemite National Park Bill, established the Yosemite and Sequoia National Parks in California. 1891 — Oscar Baumann, Austrian explorer of East Africa, publishes an eye-witness account of the extreme drought period 1883–1902 called Emutai by the Maasai.Impact of climate 2006. Africa physorg.com — General Revision Act. 1892 — John Muir, (1838–1914), founded the Sierra Club. 1895 — Svante Arrhenius presented to the Stockholm Physical Society the paper “On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground.” It is the first scientific work concerning the influence of a rise in carbon dioxide on atmospheric warming. He used previous studies by Josef Stefan, Arvid Högbom, Samuel Langley, Léon Teisserenc de Bort, Knut Ångström, Alexander Buchan, Luigi De Marchi, Joseph Fourier, C.S.M. Pouillet, and John Tyndall. 1895 — Sewage cleanup in London means the return of some fish species (grilse, whitebait, flounder, eel, smelt) to the River Thames.

20th century

1902 — George Washington Carver writes How to Build Up Worn Out Soils. 1903 — March 14, US President Theodore Roosevelt creates first National Bird Preserve, (the beginning of the Wildlife Refuge system), on Pelican Island, Florida — 7300 hectares of land in the Lake District of the Andes foothills in Patagonia are donated by Francisco Moreno as the first park, Nahuel Huapi National Park, in what eventually becomes the National Park System of Argentina. 1905 — The term smog is coined by Henry Antoine Des Voeux in a London meeting to express concern over air pollution.