1865: John Tyndall postulated that gases such as water vapour and CO2 in the ???atmospheric envelope??? retain the heat. 1896: Svante Arrhenius predicted that increases of atmospheric CO2 from burning fossil fuels would lead to global warming; a doubling of atmospheric CO2 could cause global average temperature to rise by 5??C. The predictions of this Nobel Prize laureate (1903) went unnoticed for