She put carbon dioxide in a jar, set it in the sun, and became the first person to describe a warming world.
On a clear day in 1856, a woman in upstate New York filled a pair of glass cylinders with different airs, slid a thermometer into each, and stood them side by side in the sunshine. Hydrogen climbed to 104°F. Ordinary air reached 106°, oxygen 108°. The cylinder she had charged with carbonic acid gas — carbon dioxide — went to 125°, and when she carried it into the shade it was, in her words, "many times as long in cooling." From that gap of nineteen degrees Eunice Newton Foote drew the largest conclusion anyone had yet drawn from a thermometer: that an atmosphere holding more of that gas would make the whole Earth hotter.
She was thirty-seven, trained at a girls' seminary in Troy and at the science lectures next door — about as much formal science as America then offered a woman. Eight years earlier she had signed the Declaration of Sentiments at Seneca Falls, fifth of the sixty-eight women who put their names to it. When her paper reached the American Association for the Advancement of Science that August, custom did not permit her to read it aloud; a man read it for her. The Association printed the meeting's papers in its Proceedings and left hers out. Three years later an Irish physicist in London ran finer versions of the same experiment, and for the next century and a half the greenhouse effect belonged to him.
A life between two revolutions
The lifeline
1819
Born in Goshen, Connecticut, to Isaac Newton Jr. — a distant relation of the famous one
1836
Enters the Troy Female Seminary, and the science lectures at the Rensselaer school nearby
1848
Signs the Declaration of Sentiments at Seneca Falls and helps edit the proceedings
1856
Her carbon-dioxide paper is read aloud at the AAAS in Albany — by someone else
1857
Returns with a second paper, on electrical charge in atmospheric gases
1888
Dies at Lenox, Massachusetts, at 69, her experiment already forgotten
By the numbers
The measure of her
125°F
What her carbon-dioxide cylinder reached in the sun — ordinary air managed 106°
3
Years by which she beat John Tyndall to the heat-trapping power of CO2
5th
Of the 68 women who signed the Declaration of Sentiments at Seneca Falls
155
Years her paper lay unread before a 2011 article pulled it back into the light
What she proved, wrote and built
The work
1848
The Declaration of Sentiments. She signs it at Seneca Falls and serves as one of five women appointed to prepare the convention's proceedings for publication.
1856
"Circumstances Affecting the Heat of the Sun's Rays." Read at the AAAS meeting in Albany on 23 August by Joseph Henry of the Smithsonian, and printed in full in the American Journal of Science and Arts. The first experiment to tie carbon dioxide in the air to a hotter Earth.
1857
"On a New Source of Electrical Excitation." Read at the AAAS in Montreal — this one the Proceedings did print.
1860
US Patent 28,265. A vulcanised rubber filling for the soles of boots and shoes, to stop them squeaking.
1864
US Patent 45,149. An improvement to the cylinder paper-making machine.
Erased, then recovered
Recognition
In her lifetime
Custom barred her from reading her own paper; Joseph Henry read it for her
The AAAS Proceedings printed the meeting's papers — but not hers
Tyndall's 1859 experiments took the credit, and never cited her
Scientific American praised her under the headline "Scientific Ladies"
No portrait or photograph of her is known to survive
Today
A 2011 article by the geologist Ray Sorenson returned her paper to circulation
The Royal Society published a full reconstruction of her experiments in 2020
Google marked her 204th birthday in 2023 with a Doodle — an imagined face
She is now widely named the first person to describe the greenhouse effect
Her 1856 paper is public domain and free to read in full
The village on the Seneca River
Seneca Falls
She and her husband Elisha settled in Seneca Falls, New York, in 1841 — a mill village on the river, and by accident of history the place where American women first gathered to demand their rights. Both Footes were in the Wesleyan Chapel in July 1848. The same hands that signed the Declaration of Sentiments there would, eight years later, fill the cylinders.
1841
The year she settled in the village, aged twenty-two
68
Women who signed the Declaration there; she was the fifth
2
Days the convention ran — 19 and 20 July 1848
"An atmosphere of that gas would give to our earth a high temperature."
— Eunice Newton Foote, 1856