She holds two Doctor of Philosophy degrees: in technology from Lund University, Sweden and in business administration from Copenhagen Business School, Denmark.
She chaired her party from 2005 until 2009 and was the Minister of Labour in the Finnish government from 2007 to 2009 as part of Matti Vanhanen"s second cabinet. Tarja Cronberg became Member of the European Parliament in 2011 by replacing Heidi Hautala who became Minister of International Development in the Finnish cabinet. During her 2011–2014 term in the European Union Parliament, Cronberg was the chair of the European Parliament delegation for relations with Iran and served on the Committee on Foreign Affairs and the Subcommittee on Security and Defence.
Cronberg has worked in various positions in both business and education, such as an associate professorship at the Technical University of Denmark, among others
She has long exercised political leadership in Europe"s networked society. Cronberg has been involved in technology and the social sciences policy.
She directed the North Karelia regional development council from 1993 to 2001 and led the Copenhagen Peace Research Institute from 2001 to 2003. The focal point in Cronberg"s work in recent times has been peace and security.
After the Cold War she worked both in Russia and in the United States studying the conversion of military industries into civilian uses.
Together with Stanford University and the Permanent Technical University she and her team studied the transformation processes mainly in the aerospace industry. As the Regional Director of North Karelia she was instrumental in establishing "soft borders" between Finnish border regions and the Karelian Republic on the Russian side. Her work led to the establishment of Euregio Karelia, a cross-border region with common development programmes and projects.
Later, as the director of COPRI, Copenhagen Peace Research Institute she was involved in the further development of the Copenhagen School of Security Studies, doing also work on missile defence and dual-use technologies.
In her political work she has specialised in defence and security matters, lately in questions of nuclear disarmament. Her choice of committees in the European Union Parliament reflects these interests, as does her work as the Chair of the Parliament"s delegation for relations with Iran.
In addition to her native Finnish, Cronberg is fluent in Danish, English, French, German, Russian and Swedish. She was diagnosed with breast cancer at the turn of the year 2008/2009.
She chaired the Green League party from 2005 to 2009 and served on several parliamentary committees (foreign affairs, security and defense, employment).
Cronberg was Member of the Finnish Parliament 2003–2007. She was a Member of the Finnish Parliament from 2003 to 2007 and the Minister of Labour from 2007 to 2009. She was a member of the European Union Competitiveness Council (2008-2009) and of the European Union Employment and Social Affairs Council (2007-2009).
She was a member of the Danish Parliament Technology Council (1986-1991) and the Norwegian Research Council dealing with Information Technology and society (1984-1992).
She was a member of the European Commission Information Society Technologies Advisory Group (ISTAG) from 1999 to 2002. Chaired the European Union COSTA4 Group that examined the relationship between technology and society (1992-1997) and contributed to the VALUE think-tank that focused on the interaction between research and society (1993-1994).