Global warming
Starting in 1859, John Tyndall showed that nitrogen and oxygen—together totaling 99% of dry air—are transparent to radiated heat. However, water vapour and gases such as methane and carbon dioxide absorb radiated heat and re-radiate that heat into the atmosphere. Tyndall suggested that changes in the concentration of these gases may have caused climatic changes in the past, including ice ages. In 1896, Svante Arrhenius tried to prove that it would take thousands of years for the industrial production of CO2 to raise the Earth’s temperature 5-6°C.