Geoffrey D. Carnall has taken the degrees of M.A. and B.Litt. He was appointed as a Lecturer in English Literature at Edinburgh University in 1960 and in 2003 was still an Honorary Fellow at The School of Literatures, Languages and Cultures.

In 1969, Carnall initiated, with Martin Pollock, the then Professor of Molecular Biology, a teach-in at Edinburgh University on the topic of Chemical and Biological Warfare (a teach-in being 'a prolonged and public discussion on a matter of national concern' and a concept originally growing out of the nature and conduct of the Vietnam War). Key experts came to Edinburgh, including a Government Minister and senior staff from the Research Establishment at Porton Down. Mr. Tam Dalyell (elected Edinburgh University Rector in 2003) was also present as a speaker, as was Mr. V. G. Filatov, a Counsellor at the (then) Soviet Embassy.

Carnall has published Robert Southey and his age: the development of a conservative mind (1960, Robert Southey (1964), and To keep the peace (1965). He co-edited The Impeachment of Warren Hastings: papers from a bicentenary commemoration (1989), and he edited and completed John Butt's The mid-eighteenth century (1979) and Marjorie Sykes An Indian tapestry: Quaker threads in the history of India, Pakistan and Bangladesh; from the seventeenth century to independence (1997). With others he was involved in The representation of business in English literature (2000). His most recent work had been Gandhi’s Interpreter: a life of Horace Alexander (2010). He has also published many essays.

Geoffrey Douglas Carnall died in Edinburgh Royal Infirmary on 20 February 2015, and he was cremated at Mortonhall on 27 February 2015.