When was the first ecocide “committed”?
Solution 1:
Ecocide is one of several words formed from the prefix eco-, which generated words in English after ecology came into wider usage. According to the OED, many of these words were formed in the early 20th century, and ecocide has usage cited from 1969 (Oxford English Dictionary, eco-, comb. form):
1969 Encycl. Sci. Suppl. (Grolier) 159 Discarded automobiles, old newspapers and telephone books, tin cans, nonreturnable bottles—all add to the growing problems of solid-waste disposal... Ecocide—the murder of the environment—is everybody's business.
This date corresponds to the Merriam-Webster date. To see if I can find anything further, I'm using two databases. Indications from these results is that (a) ecocide referred to a pesticide in the 1960s, and (b) gained its more general environmental usage by 1970.
JSTOR - Egler, Frank E. Ecology, vol. 47, no. 6, 1966, pp. 1077–1084. JSTOR, www.jstor.org/stable/1935663.
Further sound thoughts on this general subject are voiced by Roland C. Clement in a talk on "Mosquito control and wildlife," April 20, 1966, to the Northeastern Conference on Mosquito Suppression and Wildlife Management, at Newton, Mass. In the equally problematic field of vertebrate pest control, Alfred G. Etter's "Testimony of an ex-federal trapper" (De- fenders of Wildlife, July, 1965) reveals one of the most vigorous one-strand specialists in our society, the Sheep- man, together with the branches of our government that he has intimidated, as the subject relates to the ecocide 1080.
"Ecocide 1080"? I thought it was a numbering error at first, but according to Norbert Finzsch (2018) this is one name for a pesticide used in the early 1960s:
A substance with the scientific name sodium fluoracetate, that was used as rodent killer in the US and as 'dingo bait' in Australia, was called 'ecocide 1080.'
Finzsch cites 1080 as the origin of ecocide; the chemical is well-documented (Wikipedia). JSTOR turns up one more citation before 1970, also authored by Frank Egler, where he again refers to "ecocide 1080 (sodium fluoracetate)" : Egler, Frank E. American Scientist, vol. 56, no. 4, 1968, pp. 484A–486A. JSTOR, www.jstor.org/stable/27828398.
New York Times archive - "And a Plea to Ban 'Ecocide'." New York Times (1923-Current file), Feb 26, 1970, pp. 38.
Taking his cue from the Convention on Genocide, a Yale biologist has proposed a new international agreement to ban "Ecocide" - the willful destruction of the environment. Prof. Arthur Galston, director of the Division of Biological Sciences at Yale, made the suggestion last week at a conference in Washington on War and National Responsibility. In doing so, he pointed with alarm to United States defoliation and crop-destroying practices in South Vietnam, where he said there is evidence of "irreversible damage" to plant life.
This is the most commonly cited origin of the term in academic articles I've found. Even in 1970, the New York Times treats this as a new usage (using quotes reserved for nonce words and new words), indicating that they may have been unaware of the academic use to refer to the pesticide 1080 in the previous decade. On the other hand, given that Galston was a biologist and seemed to work in ecology, it seems likely he was aware of Frank Egler or other ecologists using ecocide to refer to pesticides. Galston's addition was to use the term more generally to refer to ecological destruction, rather than to the mere destruction of a single species by a product.
Note: One open question is how, according to the OED, an Encyclopedia Science Supplement from 1969 could have a definition that Galston uses in 1970. If anyone has access to a vintage book collection, maybe they could confirm the citation and actual publication date.