Lord Northesk inherited the earldom on his father's death in 1994, his elder brother having been accidentally drowned in infancy.

In the House of Lords, he spoke on topics relating to civil liberties and privacy, and spoke out against the Identity Cards Act 2006 and new online copyright laws such as those contained in the Digital Economy Act 2010.

They had four children: In 2001, his eldest child and only son Lord Rosehill, a psychiatric patient, shot himself in the head with his father's gun whilst on leave from hospital at the family's farm in West Sussex.

Northesk died at the age of 55 from cancer[1] and was succeeded in the earldom by his eighth cousin once removed, Patrick Carnegy.

His vacated seat in the House of Lords triggered a by-election for a Conservative hereditary peer to replace him.