The Story:
In the mid 1890s a Swedish chemist, Sven Arrhenius, published the first-ever model of atmospheric change based in variant levels of CO2. He posited that the doubling of the amount of CO2 that was in the air at that time would lead to an increase of temperature of between 5 and 6 degrees celsius. This didn’t seem a very imminent threat to Arrhenius: he also postulated that such a doubling of the amount of CO2 would take 3,000 years.
Significance:
Arrhenius was awarded the first ever Nobel Prize in Chemistry, when the award was established in 1903, though that was for work largely unrelated to his climate modeling. He is now regarded as both a pioneer of modern chemistry and a pioneer of climate science.
Erroneous time scale notwithstanding, Arrhenius’ postulated link between changes in CO2 level and changes in temperature doesn’t seem very far off from where the present consensus on that subject stands.
Strange New Worlds:
Arrhenius’ own interest in the subject resulted from looking back, not forward. It had in his time only recently become an established geological fact that the globe had seen multiple advances and retreats of glaciation (Ice Ages). Arrhenius was interested in looking systematically, as a chemical problem, at how that alternation of “ages” can come about. Yet his work also serve us as a warning. Early hominids may have struggled with the advance of glaciers. Twenty-first century hominids are arguing about the consequences of the melting of glaciers.
