When Was the Greenhouse Effect Discovered?

In 1824, French mathematician Joseph Fourier calculated that Earth should be much colder than it is based on its distance from the Sun, and proposed that the atmosphere must trap heat. In 1856, American scientist Eunice Newton Foote conducted experiments showing that a glass cylinder filled with CO2 heated more in sunlight than one filled with air — the first experimental demonstration of CO2 greenhouse warming. In 1859, Irish physicist John Tyndall (apparently unaware of Foote work) measured the heat absorption of various gases, showing CO2 and water vapour were powerful infrared absorbers. In 1896, Swedish chemist Svante Arrhenius calculated that doubling atmospheric CO2 would raise global temperatures by about 4-6 degrees Celsius — remarkably close to modern climate sensitivity estimates. His work was prescient but largely ignored for decades.