From 1995 to 1996 Haug worked as a postdoc at
GEOMAR, Helmholtz Center for Ocean Research Kiel, Germany. From 1996 to 1997 he had been a postdoctoral fellow in the Department of Oceanography at the
University of British Columbia, Vancouver, Canada. Subsequently, he worked as a postdoctoral student at the Woods Hole Oceanographic Institution in Massachusetts, United States, and became later a research assistant professor at the
University of Southern California, Los Angeles, United States (1997–1998). From 2000 to 2002, he worked as a senior assistant at the
ETH Zürich, Switzerland, and habilitated in the
Earth Sciences (2002). Haug is signee of a protest note which points out the dangers arising from ignoring climate change. Haug initiated the construction of the
research sail yacht S/Y Eugen Seibold and coordinates the research. ==Other activities==