He worked as a public health officer and hospital manager in Norway, and conducted research and published a textbook in the planning and management of primary health care. He served on a number of boards for health care providers, investors and start-ups, including the European Federation of Biotechnology and the ScanBalt biotechnology network. He spent five years as a special advisor to the Norwegian Trade Council, and served two years in that function in San Francisco (1999–2001). In 2007 he became a board member of Public Advice International Foundation. In 2008, Christie became a board member of EduMonde SA (an educational media venture) and a member of the Presidium of the United Nations'International Eco-Safety Cooperative Organization.
In 2001 he started his own full-time consulting business, World Health Connections, focusing on entrepreneurship and investment strategies in medical technology and biotechnology, as well as health care development and consulting. He was appointed in May 2004 as Science and Technology Counsellor for the Royal Norwegian Embassy in Beijing, China, where his work is mainly focused on energy, environmental, building, medical, marine and biological sciences and technologies as well as welfare and health reform issues.