On August 23, 1856, Eunice Foote's work is presented to a meeting of the American Association for the Advancement of Science (AAAS) in Albany, New York. She is the first to articulate the possibility of global warming from carbon dioxide in the atmosphere.
Eunice Foot was a scientist, inventor, women's rights campaigner, wife and mother. Her 1856 paper, "Circumstances affecting the heat of the sun's rays", argued that carbon dioxide and water vapor absorbed and held heat from the sun more readily than other gases. Foote's experiment used an air pump and cylindrical jars to measure changes in the air temperature of various gases in the sun and in the shade.
Her work was presented at a meeting of the AAAS, but she did not present it herself—a friend, Joseph Henry, presented her paper for her. As an amateur scientist and as a woman, Foote likely would not have been taken seriously had she presented her research herself. At the time, no one who read Foote's findings seems to have appreciated their importance. Joseph Henry admitted that he had difficulty in "interpret[ing] their significance."
John Tyndall, a renowned Irish physicist, was originally credited with the discovery of carbon dioxide's ability to absorb radiation. His first paper on the subject was published in 1859, three years after Foote's. (There is no direct evidence that Tyndall ever read Foote's work.) Tyndall's experiment was more sophisticated and accurate than Foote's, and accounted for the role of infrared radiation from Earth, as well as solar radiation from the sun.
Tyndall was a respected member of prestigious European scientific circles; his work was widely appreciated, and laid the foundation for the modern understanding of the greenhouse effect. The work of Foote, an amateur and a woman, was largely forgotten. Her contribution to climate science was only rediscovered by scholars in 2011. However, both Tyndall and Foote reached the same fundamental conclusion: that increased CO2 in the atmosphere would increase Earth's temperature.