1. Invention of 2,4,5, trichlorophenoxyacetic acid. During the Vietnam War (1965-1971), it is used as a defoliant under the codename Agent Orange. It is expected that contaminated soil will need over a century to regenerate.

  2. Discovery of insecticide DDT. P. Müller receives the Nobel Prize in 1948. DDT has been banned in Germany since 1972.

  3. Otto Hahn and Fritz Straßmann discover nuclear fission.

  4. Over these 40 years, the lake's phosphate concentrations rise from zero to 26 mg/m_, its nitrate content from 600 mg/m_ to 800 mg/m_. The mass of phytoplankton is a factor of twenty greater. The whitefish catch falls to an all-time low in 1963. A convention on safeguarding the water quality in the Bodensee is accepted in 1961. Eutrophication in the Bodensee remains stable from 1975.

  5. Sewage containing mercury is released by Chisso's chemicals works into Minimata Bay in Japan. The mercury accumulates in sea creatures, leading eventually to mercury poisoning in the population.

  6. World Animal Day was started in 1931 at a convention of ecologists in Florence as a way of highlighting the plight of endangered species. Since then it has grown to encompass all kinds of animal life and is widely celebrated in countries throughout the world. October 4 was chosen as World Animal Day as it is the Feast Day of St Francis of Assisi, the patron saint of animals.

  7. The first patent for production of synthetic fibres is granted. Under the Nazi policy of self-sufficiency, the industry expands greatly in the 1930s.

  8. A "fog disaster" in Maastal near Lüttich claims 100 lives.

  9. NABU (then the BfV) starts a campaign against destruction of the countryside through land clearance.

  10. Hermann Joseph Müller (1890 - 1965) discovers X-rays to be agents of mutation.

  11. The first German Nature Conservation Day (Deutscher Naturschutztag DNT) took place in Munich from 26 July - 28 July 1925. Since 1957 the conference is held every two years.

  12. Accident insurance is extended, at first to cover 11 occupational illnesses.

  13. A Prussian act to protect trees is passed in 1922, with positive effects in conurbations, above all.

  14. The Oppau explosion occurred on September 21, 1921 when a tower silo storing 4,500 tonnes of a mixture of ammonium sulfate and ammonium nitrate fertilizer exploded at a BASF plant in Oppau, now part of Ludwigshafen, Germany, killing 561 people and injuring about 2,000 more. About 80 percent of all buildings in Oppau were destroyed.

  15. Compensation and widows' pensions granted in case of illness caused by aromatic nitrogen compounds.

  16. Ammonia needed for nitrogen fertiliser and munitions is produced synthetically.

  17. The first international conference on nature conservation takes place in Bern.

  18. The "Verein Naturschutzpark" sets up a protected nature park on the Lüneburg Heath.

  19. The Lakeview Gusher Number One was an immense out-of-control pressurized oil well in the Midway-Sunset Oil Field in Kern County, California, resulting in what is regarded as one of the largest oil spills in history, lasting 18 months and releasing 1.400.000m³ of crude oil.

  20. NABU (then the BfV) organises Germany's first Bird Conservation Day in Berlin.

  21. Prussia sets up a State Office for the Care of Natural Heritage.

  22. The Congress concludes that "poor water quality threatened fisheries with total ruin."

  23. The Emscher cooperative is founded to regulate sewage treatment in the Ruhrgebiet. Similar cooperatives follow: Ruhrverband, Lippeverband, Niersverband, Wupperverband.

  24. NABU (then the BfV) starts a campaign to save the yellow-billed egret and the bird of paradise, which are hunted for their feathers (for use in women's hats).

  25. In 1901, the Royal Insititute for Research and Testing in Water Supply and Waste Disposal is founded, becoming the Royal State Insititute for Water Hygiene in 1913, the Prussian State Institute for Water, Soil and Air in 1923, the Imperial Institute for Water, Soil and Air in 1942, before finally settling down as the Institute for Water, Soil and Air Hygiene under the Federal Health Office in 1952. In 1994, it became a department of the FEA, merging with it completely in 1999.

  26. The "Society for Protection of Birds" (BfV) is founded by Lina Hähnle. In 1906, members of the aristocracy are successfully recruited, including the kings of Sweden, Rumania and Bulgaria, the royal couple in Wurttemburg, as well as most German Counts. US president Wilson joins in 1912, when the society gains charitable status. In 1934, the Forestry Minister orders it to be renamed the "Imperial Society for Protection of Birds" (RfV). After 1945, the society rebuilds in West Germany with its former name, becoming the "German Society for Protection of Birds" (DBV) with its White Stork logo in 1966, while the East German society is first subsumed under the GDR Cultural Society. After reunification, the society merges with the GDR Conservation Society to form the German Nature Conservation Society (NABU). After 100 years, NABU has 225,000 members, organised in some 200 local and youth groups, as well as 15 regional (Land) societies.

  27. The Baltic Sea is suffering from a lack of oxygen. Poor oxygen conditions on the seabed are killing animals and plants, and experts are now sounding the alarm – releasing fewer nutrients into the Baltic Sea is absolutely necessary. After several years of discussions, researchers from Aarhus University (Denmark), Lund University and Stockholm University (Sweden) have determined that nutrients from the land are the main cause of widespread areas of oxygen depletion. During the last century, the areas of oxygen depletion have increased drastically from approximately 5,000 km2 in around 1900 to the present day, where they extend to 60,000 km2. The results were published on 31 March in the journal Proceedings of the National Academy of Sciences.

  28. In his authoritative speech as President of the British Association for the Advancement of Science, the physicist William Crookes (1832 - 1919) warns of the scarcity of resources, particularly nitrogen fertiliser.

  29. W.C. Röntgen discovers X-rays and receives the first Nobel Prize for physics in 1901.

  30. The world's first waste incinerator comes into operation in Hamburg.

  31. The Sierra Club was founded on May 28, 1892, by John Muir, a noted preservationist, and a group of influential friends who sought to create an organization to protect the boundaries of the newly established Yosemite National Park. Today, the Sierra Club has over 1.3 million members and supporters and is the oldest, largest, and most influential grassroots environmental organization in the United States.

  32. The hydroelectric plant Lauffen on the Neckar provides power to Frankfurt, 175 km away, marking the start of distributed electricity supply.

  33. The first German drinking water reservoir comes into operation at Remscheid. By WW1, more reservoirs are built, such as at the Eder and Möhne valleys.

  34. The first sewage treatment works comes into operation in Frankfurt-Niederrad.

  35. Robert Hasenclever (1841 - 1902), a soda producer in Stolberg, reports to the Aachen Scientific Society on desulphurisation of "smelting smoke", and publishes "On Harm to Vegetation Through Acid Gas" - a pioneering achievement in air quality.

  36. The first hydroelectric power is used to illuminate Castle Linderhof in Bavaria.

  37. Berlin's sewage system is begun. Following Gdansk's example, the sewage is passed onto sewage fields.

  38. The Yellowstone First National Park situated in the US states Wyoming (96%), Montana (3%), and Idaho (1%) was founded on March 1st, 1872 as the first national park of the world, setting an example followed in other countries, including Germany.

  39. On July, 13th, 1870 the Royal Prussian Commission for the Research of the German Seas took up work in Kiel on behalf of the fishery. The commission had been established by the Royal Prussian Ministry of Agricultural Affairs aiming at improved fishing results.

  40. At their 26th general meeting, farmers and foresters pass a resolution protecting birds deemed useful to agriculture. An international agreement follows in 1902.