Professor Sir Nicholas John Shackleton FRS was an English geologist and paleoclimatologist who specialised in the Quaternary Period. He was the son of the distinguished field geologist Robert Millner Shackleton and great-nephew of the explorer Ernest Shackleton.
Educated at Cranbrook School, Kent Shackleton went on to read natural sciences at Clare College, Cambridge. He graduated with the Bachelor of Arts degree in 1961, and, in 1964, with the Master of Arts degree. In 1967 Cambridge awarded him a PhD degree, for a thesis entitled "The Measurement of Paleotemperatures in the Quaternary Era".
Apart from periods abroad as Visiting Professor or Research Associate, Shackleton's entire scientific career was spent at Cambridge. He became Ad hominem Professor in 1991, in the Department of Earth Sciences, working in the Godwin Institute for Quaternary Research.
Shackleton was a key figure in the field of palaeoceanography, publishing over two hundred scientific papers. He was a pioneer in the use of mass spectrometry to determine changes in climate as recorded in the oxygen isotope composition of calcareous microfossils. Shackleton also found evidence that the Earth's last magnetic field reversal was 780,000 years ago. He became internationally known, in 1976, with the publication of a paper, with James Hays and John Imbrie, in Science entitled "Variations in the Earth's orbit: Pacemaker of the ice ages". Using ocean sediment cores, Shackleton, Hays and Imbrie demonstrated that oscillations in climate over the past few million years could be correlated with variations in the orbital and positional relationship between the Earth and the Sun.