James Croll (2 January 1821 – 15 December 1890) was a Scottish physical scientist who was the leading proponent of an astronomical theory of climate change in the 19th century. The son of a stonemason and crofter from Cargill in Scotland, he started work as a millwright, but became caretaker at Anderson's College, Glasgow, in 1859, where he was in charge of the library with ample time for reading. He was later appointed resident geologist in the Edinburgh office of the Geological Survey, where he remained until he retired in 1880. Croll, who was effectively self-taught, is best known for his work on the astronomical theory of the ice ages, but he also made major contributions on the glacial geology of Scotland, on the mechanisms that drive ocean circulation and the impact of that circulation on climate, tidal theory and the rotation of the Earth.  His insights into the interplay between astronomical and geological factors – into cosmic physics and climate dynamics -- were extremely influential.
Climate and Time
In 1875 Croll published his major book Climate and Time which had a profound influence on geologists around the world. Charles Lyell, the leading geologist of the time, revised his Principles of Geology in response to Croll’s theory. His view was notably followed by James Geikie in The Great Ice Age (1874–84),
In 1864, inspired by Joseph Adhémar’s Révolutions de la mer (1842), Croll published an article entitled On the Physical Cause of the Change of Climate During Geological Epochs, where he proposed that periodic variations in the earth’s orbit around the sun accounted for the periodic variations in climate evidenced by geological evidence of ice ages , and alternating cold and warm periods in each hemisphere (i.e. that ice ages in the Northern Hemisphere coincided with interglacials in the Southern Hemisphere). He proposed that feedback mechanisms, including the radiative effects of the ice fields, enhanced formation of cloud and fog, changes in sea level, and the mixing and redirection of warm and cold ocean currents enhanced the climatic changes initiated by the orbital changes. Because of uncertainties in the timing of ice ages, and because Croll’s theory predicted glaciation in only one hemisphere at a time, his theory was disregarded at first. Nevertheless, Croll's work attracted much attention, not least because Croll had worked with none of the advantages of a scientific training, and he was awarded the Wollaston Medal of the Geological Society of England in 1872.
Croll's other works included The Philosophy of Theism (1857), Climate and Cosmology (1885) and The Philosophic Basis of Evolution (1890). In 1876, Croll was elected as a Fellow of the Royal Society and was awarded an honorary doctorate from the University of St Andrews. His 1889 book Stellar Evolution and Its Relations to Geological Time contains "the first modern attempt to explain the chemical composition of the stars"
- International Commission on History of Meteoro, James Fleming (Lead Author);Cutler Cleveland (Topic Editor) "James Croll and the astronomical theory of climate change". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth May 5, 2007; Last revised Date May 5, 2007; Retrieved December 19, 2010
- James Croll F.R.S. Nature 43:180-181 (1890)
- Sketch of James Croll Popular Science Monthly August 1897
- Fleming JR (2006) James Croll in Context: The Encounter between Climate Dynamics and Geology in the Second Half of the Nineteenth Century History of Meteorology 3:43-54
- Croll, James, 1875. Climate and Time in Their Geological Relations. A theory of secular changes of the earth's climate. New York.
- James Croll (1886) Discussions on Climate and Cosmology Appleton, New York Contemporary review in The American Naturalist 20:359-61 (1886)
- James Croll (1890) The Philosophic Basis of Evolution pub. Edward Stanford, London Contemporary review by Thomas Whittaker in Mind 16:268-71 (1891)
- James Croll (1889) Stellar Evolution and Its Relations to Geological Time: New York, Appleton
- A concise history of solar and stellar physics By Jean Louis Tassoul, Monique Tassoul (2004) Princeton University Press ISBN: 069111711X