Eunice Newton Foote (July 17, 1819 – September 30, 1888) was an American scientist (including biology, especially botany), an inventor, and a women's rights campaigner from Seneca Falls, New York.

She was the first scientist known to have experimented on the warming effect of sunlight on different gases, and went on to theorize that changing the proportion of carbon dioxide in the atmosphere would change its temperature, in her paper Circumstances affecting the heat of the sun's rays at the American Association for the Advancement of Science conference in 1856. Although it appears that women were allowed to present papers to AAAS at that time, Professor Joseph Henry of the Smithsonian Institution delivered the paper that identified the research as her work. 


Local historian tells ‘long-forgotten story’ of scientist, suffragist from Bloomfield ( 



Foote conducted a series of experiments that demonstrated the interactions of the sun's rays on different gases. She used an air pump, four mercury thermometers, and two glass cylinders. First she placed two thermometers in each cylinder, then by using the air pump, she evacuated the air from one cylinder and compressed it in the other. Allowing both cylinders to reach the same temperature, she placed the cylinders in the sunlight to measure temperature variance once heated and under different moisture conditions. She performed this experiment on CO2, common air, and hydrogen. Of the gases she tested, Foote concluded that carbon dioxide (CO2) trapped the most heat, reaching a temperature of 125 °F (52 °C). From this experiment, she stated "“The receiver containing this gas became itself much heated—very sensibly more so than the other—and on being removed [from the Sun], it was many times as long in cooling.” Looking to the history of the Earth, Foote theorized that "An atmosphere of that gas would give to our earth a high temperature; and if, as some suppose, at one period of its history, the air had mixed with it a larger proportion than at present, an increased temperature from its own action, as well as from increased weight, must have necessarily resulted."

Foote illustrated her findings in a paper entitled, Circumstances affecting the heat of the sun's rays, which was accepted at the eighth annual American Association for the Advancement of Science meeting on August 23, 1856 in Albany, NY. It is not clear why Foote did not present her own work at the conference, as women were in principle allowed to speak, but the presentation of her paper was made instead by Prof. John Henry of the Smithsonian Institution. Before reading Foote's work, Henry introduced the findings by stating "Science was of no country and of no sex. The sphere of woman embraces not only the beautiful and the useful, but the true". Foote's paper was published later the same year under her name in the American Journal of Science and Arts. However, this paper was not included in Proceedings from 1856, which was the published work from the AAAS meetings of the year. A summary of Eunice Foote's work was published in The 1857 Anneal of Scientific Discovery, a book containing reviews of scientific progress in the year proceeding each publication (pg. 159–160). Summaries of Eunice Foote's findings were also reported in the New York Daily Tribune, Canadian Journal of Industry, Science and Art, and Scientific American as well as the European journals Jahresbericht in 1856 and the Edinburgh New Philosophical Journal in 1857. However, Eunice's brief recognition was not complete. Both European summaries omitted her direct conclusions about the impact of carbon dioxide on climate, and the summary written in the Edinburgh New Philosophical Journal misrefers to the scientist as “Elisha Foote”, Eunice's husband. Meanwhile, Foote was praised in the September 1856 issue of Scientific American titled "Scientific Ladies." The authors were impressed with her findings backed up by her experiments, stating, "this we are happy to say has been done by a lady.” An extensive analysis of Foote's 1856 paper was published in 2020 by Joseph D. Ortiz, a paleo-climatologist and Roland Jackson, a historian of science. Their work explores how Foote related changes in the types and amounts of atmospheric gases, including carbon dioxide, to warming and changes in climate. It traces the derivation of her ideas and explores how she constructed, carried out, and interpreted her experiments.

Foote's work had shown that the heating effect of sunlight was affected by CO2 and water vapour in the atmosphere. Three years later, John Tyndall reported his more sophisticated research which showed that various gases both trapped and emitted infrared thermal radiation rather than sunlight. His work was published by the Proceedings of the Royal Society, where he was a fellow, and is commonly regarded as foundational to climate science. He gave credit to Pouillet's work on solar radiation through the atmosphere, but appears to have been unaware of Foote's work, or did not think it was relevant. Foote's work is discussed by Ralph Lorenz in a modern planetary climate context, who notes that the near-infrared (0.8 to 3 μm) radiation absorption reported by Foote is effectively an "antigreenhouse effect" because it involves primarily solar radiation absorption rather than absorption and re-radiation of terrestrial longwave ('thermal') infrared radiation. This distinction was not fully appreciated in the 1850s.


In 2010, retired petroleum geologist Ray Sorenson came across Foote's work in a 1857 volume of Annual Scientific Discovery. He quickly realized that Foote was the first to make the connection between carbon dioxide and climate change and that her work had gone unrecognized. In January 2011, Sorenson published his findings on Foote in AAPG Search and Discovery, where it received "more response than any of his other work". A symposium in May 2018 led by John Perlin, a Visiting Scholar in the Department of Physics at the University of California, Santa Barbara, discussed Foote's contributions to climate change science, women's rights and the question of priority over the claim that a man, John Tyndall, discovered the role of carbon dioxide in global warming. In November 2019 the library of the University of California, Santa Barbara, displayed an exhibit to honor Foote's work and legacy, presenting the claim thatshe had discovered that "CO2 is uniquely proficient at absorbing and radiating solar heat back to earth". Perlin, who is writing a book about Foote to claim her primacy in laying the foundation for understanding the greenhouse effect, said "I call her the Rosa Parks of science".

From a modern perspective it seems strange that Foote's work was not noticed by other researchers. Historian of science Roland Jackson, a Visiting Fellow at the Royal Institution, set out to analyse the social context and questions of priority. Foote's paper gives only outline information about her apparatus and does not name those who influenced her. Similar apparatus had been introduced in the 1770s by de Saussure, and Foote deserves credit as the first to experiment with different gases. Scientists in Europe were looking into the roles of sunlight and "obscure heat" or "terrestrial radiation" (now known as infrared) in what we now call the greenhouse effect, and Tyndall cited de Saussure, Fourier, Pouillet, and Hopkins as inspiring his research into its molecular physics. He used infrared sources, and developed Melloni's apparatus to get accurate measurements: Foote's simple apparatus could not distinguish between visible and infrared radiation. Not all researchers were aware of each other: it took two years after publication before Tyndall and Gustav Magnus realised they were both working on this topic. Foote was an amateur at a time when women were excluded from many scientific societies, and few European publications mentioned her work. Joseph Henry (who had read out her paper) could have promoted it, but did not grasp its significance, so her speculation that CO2 variation could have changed climate gained little attention. Transatlantic travel was infrequent, and though America was advanced in natural history, physics was still developing and few American physicists had an international reputation.

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