Hans was born in Frankfurt am Main (Germany). In 1990, he earned his Abitur (German high school diploma) before emigrating to Canada. He earned a B. Sc. (Honours, with distinction) from the University of Victoria in 1998 and M. Sc. and Ph.D. degrees from the University of Alberta in 2000 and 2004, respectively. He then spent 3½ years as a postdoctoral fellow at the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado. Since 2007, he has been a faculty member in the Department of Chemistry at the University of Calgary.