Karl began his career as photojournalist in 1982 working for major Swedish newspapers including staff positions at Aftonbladet. Between 1992 and 2000 working as TV documentary photographer including covering the Bosnian war for Swedish TV4. From 2003 working as photojournalist and picture editor for Dagens Nyheter, Sydsvenska Dagbladet and Svenska Dagbladet. Been working on own projects on Haiti and also focusing on global environmental issues. Awarded as Photographer of the Year 1986.
Received awards in 2007 in the Swedish Picture of the Year. Was nominated in multiple categories in 2008 Picture of the Year and won the 2008 Picture of the Year. Was honoured with the jury's special prize in Picture of the Year 2011. Nominated for the 2011 "Guldspaden" in the category National Daily Press administrated by The Association for Investigative Journalism in Sweden, for his work at Sydsvenska Dagbladet covering "Svarta Malmö". Lecturer and giving inspirational sessions for editorial staff and photography students.