Head of the Education of Research Librarians and Documentalists 1984–1986 part-time Associate Professor at the Institute of Contemporary History, University of Copenhagen, 1973–1983.

Erland Kolding Nielsen was appointed Director General af The Royal Library in March 1986.

Together with the State and University Library of Aarhus Kolding Nielsen managed for the first time in 70 years to get a new Legal Deposit Law through the Ministry of Culture, which was passed by the Parliament in 1997, and fundamentally revised again in 2004, including all digital formats.

Established in 2009 as a new part of the National Bibliography a full registration of retro-digitalised collections of all kinds in Denmark (2016, c. 330).

As member since 1987 and chair since 1995 of the Commission on Exports of Cultural Assets he channelled many books, manuscripts and archived into the Royal Library.

From 1999 the cultural functions and services of the national library to the public were greatly enlarged, including a chamber orchestra-in-residence the DiamondEnsemble from 2004, a semi-permanent treasure exhibition in the Montana Hall 2006, the International Author’s Stage 2008, and many other exhibitions, lecture series, artists’ talks, conferences, etc.

During the same period, extensive structural changes has taken place, the biggest of which is the waterfront's new landmark, the Black Diamond, which after a European architectural competition I 1993, won by Schmidt, Hammer, Lassen Architects, was completed in 1999, with the multifunctional chamber music hall, The Queen’s Hall.

IFLA, the International Federation of Library Associations and Institutions: Standing Committee of the Section for National Libraries 1989–1997, secretary 1991–1995, chair of the Division (I) for General Research Libraries, member and vice-chair of the Professional Board 1991–1993, initiator and member of the Organizing Committee of the 63rd IFLA General Conference in Copenhagen 1997, initiator and organizer of The International Conference on National Bibliographic Services, Copenhagen 1998.