Since 2009 he has been working on long-term projects including Future Cities, which focuses on informal development in the world’s fastest-growing cities and The Colorado River Project, which looks at the ways the river has affected, and been affected by, the development of the American West. His work has been featured in numerous solo and group exhibitions including those at the Loyola University Museum of Art, Foley Gallery, The Philadelphia Photo Arts Center and the Philadelphia Art Alliance. His photographs are held in collections including the Salt Institute for Documentary Studies, The Free Library of Philadelphia and The Philadelphia Museum of Art. Addis is the recipient of fellowships from the Center for Emerging Visual Artists, the Independence Foundation, and the George A. and Eliza Gardner Howard Foundation.