He focused his career on the issue of human overpopulation, and is best known for his exposition of the tragedy of the commons in a 1968 paper of the same title in Science,[1][2][3] which called attention to "the damage that innocent actions by individuals can inflict on the environment".

[17] In 1968, Hardin applied his conceptual model developed in his essay "The Tragedy of the Commons" to human population growth, the use of the Earth's natural resources, and the welfare state.

[1][citation needed] His essay cited an 1833 pamphlet by the English economist William Forster Lloyd which included an example of herders sharing a common parcel of land, which would lead to overgrazing.

"[1]: 1244  Environmental historians Joachim Radkau, Alfred Thomas Grove and Oliver Rackham criticized Hardin "as an American with no notion at all how Commons actually work".

[18] In addition, Hardin's pessimistic outlook was subsequently contradicted by Elinor Ostrom's later work on success of co-operative structures like the management of common land,[19] for which she shared the 2009 Nobel Memorial Prize in Economic Sciences with Oliver E. Williamson.

[10][24] In 1993, Garrett Hardin published Living Within Limits: Ecology, Economics, and Population Taboos, which he described at the time as a summation of all his previous works.

[26] Hardin writes, "At this late date millions of people believe in the fertility of money with an ardor seldom accorded to traditional religious doctrines".

[9] Hardin's last book The Ostrich Factor: Our Population Myopia (1999), a warning about the threat of overpopulation to the Earth's sustainable economic future, called for coercive constraints on "unqualified reproductive rights" and argued that affirmative action is a form of racism.