Prior to this, Marton-Lefèvre was Rector of the University for Peace (UPEACE), a graduate-level international university, mandated by the United Nations, providing education, training and research on issues related to peace and conflict. Earlier offices held by Marton-Lefèvre include Executive Director of LEAD (Leadership for Environment and Development) International , a programme established by The Rockefeller Foundation to bring together and train mid-career leaders from all parts of the world in improving their leadership skills around the issues of sustainable development and Executive Director of the International Council for Science (ICSU), an important and respected global organization bringing together scientific academies and unions to promote scientific activities for the benefit of humanity. Marton-Lefèvre is a member of a number of boards, councils and committees for organizations such as the China Council for International Cooperation on Environment and Development (CCICED), an advisory body to the Chinese Government, the World Future Council, UPEACE, LEAD International, the Bibliotheca Alexandria, the Geneva-based Graduate Institute of International and Development Studies, Oxford University’s James Martin 21st Century School.
Previous board memberships have included the International Institute for Environment and Development (IIED), Earth Charter International, the World Resources Institute (WRI), the International Research Institute for Climate and Society (IRI), the Lemelson Foundation, ICSU's Committee on Science and Technology in Developing Countries (COSTED) and the InterAcademy Council's Panel on Promoting Worldwide Science and Technology Capacities for the 21st Century. She was also a member of the jury of the Saint Andrew's and Alcan Prizes and has participated in two, corporate environmental advisory boards: to the Dow Chemical Company and to The Coca-Cola Company
J. Marton-Lefèvre has co-authored numerous books and papers. In 1999 she received the AAAS Award for International Cooperation in Science. In 2008, she was awarded the “Chevalier de l’Ordre national de la Légion d’Honneur” by the French Government and was named Global Ambassador for Hungarian Culture by the Hungarian Minister of Education and Culture. She is a Fellow of the Royal Geographical Society of the United Kingdom and a Fellow of the World Academy of Art and Science. She studied history, ecology and environmental planning in the US and in France and was born in Hungary. Furthermore she was keynote speaker at the global Holcim Awards Gold 2009 ceremony held in Fez, Morocco and is a member of the global Jury of the Holcim Awards 2012.