Eunice Newton Foote (July 17, 1819 – September 30, 1888) was an American scientist, inventor, and women's rights campaigner. She was the first scientist to conclude that certain gases warmed when exposed to sunlight, and that rising CO 2 levels would change atmospheric temperature and could impact climate.
In 1824 Joseph Fourier hypothesized that gases in the atmosphere create barriers that trap heat. In 1837 he surmised that over a long period of time, the amount of heat held by the atmosphere could change and be altered by both the Earth’s natural evolution and human activity.
John Tyndall (2nd August 1820 – 4th December 1893) discovered that water vapour and CO2 absorb much more radiant heat than the gases of the atmosphere and argued the consequent importance of those gases in moderating Earth's climate—that is, in the natural #GreenhouseEffect.
James Croll (1821–1890) a brilliant-minded Scotsman from Perthshire who is considered to be one of the world’s first climate scientists. Croll was the foremost advocate in the 1800s of the idea that climate change is caused by atmospheric changes between the earth and the sun.
1896 Swedish Nobel Prize winning chemist and scientist Svante Arrhenius concluded humanity could cause global #ClimateChange. He published calculations in The London, Edinburgh, Dublin Philosophical Magazine and Journal of Science showing CO2 in the atmosphere warmed the planet.
British engineer Guy Callendar, discovered the connection between human activities and #GlobalWarming in 1938. Through detailed journals on weather data, Callendar curated global temperature averages and calculated how much carbon dioxide humans were putting into the atmosphere.
Canadian physicist Gilbert Pass; 1956 concluded "If at this centuries end measurements show that atmospheric CO2 rises appreciably and at the same time the temperature continues to rise worldwide, it will firmly establish that CO2 is an important factor in AGW climatic change"