Wednesday, December 14, 2011

Croll's 1864 Paper on Climate Change

James Croll's first paper on climate change, On the Physical Cause of Climate Change during Geological Epochs, was published in 1864 in Philosophical Magazine, Vol 28. In it he starts out by reviewing earlier discussions of climate change and proposes an alternative theory. He notes that in past ages there were alternating periods of warm and cold which could be deduced from the species of sea shells that were present in the oceans around England. Glaciers and icebergs transported broken rock which ended up as breccias in the seas. A warm period was responsible for the coal formations in England. He suggests that the cold period may have been due to an absence of the Gulf Stream at that time. There is a discussion of trade winds and ocean currents. He proceeds to a discussion of Leverrier's work of the variation of the eccentricity of the Earth's orbit and the effect of the Earth's precession in alternating the temperature of the northern and southern hemispheres. Finally he correlates these temperature changes with the warm and cold periods in the two hemispheres.

Supplemental (Dec 14): Another paper, On the Change in the Obliquity of the Ecliptic, was published in the Transactions of the Geological Society of Glasgow in 1866.

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