Svante Arrhenius (1859-1927) was a Swedish scientist that was the first to claim in 1896 that fossil fuel combustion may eventually result in enhanced global warming. He proposed a relation between atmospheric carbon dioxide concentrations and temperature. He found that the average surface temperature of the earth is about 15 o C because of the infrared absorption capacity of water vapor and carbon dioxide. This is called the natural greenhouse effect. Arrhenius suggested a doubling of the CO 2 concentration would lead to a 5 o C temperature rise. He and Thomas Chamberlin calculated that human activities could warm the earth by adding carbon dioxide to the atmosphere. This research was a by-product of research of whether carbon dioxide would explain the causes of the great Ice Ages. This was not actually verified until 1987.
After the discoveries of Arrhenius and Chamberlin the topic was forgotten for a very long time. At that time it was thought than human influences were insignificant compared to natural forces, such as solar activity and ocean circulation. It was also believed that the oceans were such great carbon sinks that they would automatically cancel out our pollution. Water vapor was seen as a much more influential greenhouse gas.