on Abbatt is a professor in the Department of Chemistry at the University of Toronto. He has worked in the field of atmospheric chemistry for over 30 years, focussing primarily on processes involving the chemistry and cloud-forming properties of aerosol particles. This work is done through both field and laboratory studies. He initially was interested in the chemistry of the stratosphere and upper troposphere, but has most recently turned his attention to lower tropospheric processes that impact both climate and air quality. He obtained his PhD from Harvard, was a postdoctoral fellow at MIT, and then has held faculty positions at the University of Chicago and University of Toronto. He is a fellow of both the American Geophysical Union and the Royal Society of Canada.