James Croll (1821–1890) was a Scottish scientist who made major, although still largely unrecognised, contributions to the theory of the effects of variations in the Earth's orbit on the global climate. He was the first to identify the importance of positive feedbacks in the climate system, especially the ice-albedo feedback, and he placed the astrochronological method on a sound footing. Croll's theory was the first to predict multiple ice ages. However, it was unable to place the end of the most recent glaciation more recently than 80,000 years ago, and as evidence accumulated throughout the 19th century for a much more recent date than this Croll's theory fell into neglect. We argue that this was particularly unfortunate since several of his key ideas were forgotten, and that this has delayed the development of the orbital theory of paleoclimate.

Willi Dansgaard, a great pioneer of climate research, died on 8 January 2011 at the age of 88. He was born on 30 August 1922 and grew up in the centre of Copenhagen where his parents had an engraving shop. He finished his university degree in physics, mathematics and astronomy in 1947 with a gold medal award for a thesis on X-ray dosimetry at the Biophysics Laboratory of the University of Copenhagen. From 1947 to 1951 he was employed by the Danish Meteorological Institute where he worked in geomagnetism and meteorology. In 1947–1948 he spent a year at the geomagnetic observatory in Qeqertarsuaq, Greenland, and this led to a life long affection for that country.

John Bryan Heaney, who died in November 2010 aged 79, was an outstanding field surveyor who made a major contribution to the mapping of South Georgia and created the first accurate map of Gough Island.