Marshall is the author of dozens of academic papers and numerous books on various environmental / humanities topics, for example:
Ecotopia 2121 (2016) Arcade Publ., NY
Wild Design (2009) North Atlantic Books, Berkeley.
The Unity of Nature (2002) Imperial College Press: London
His creative works have been exhibited in galleries across the world, from the Bauhaus Museum and Museum of London in Europe to various environmental film festivals in Asia.
Marshall has worked as an international research fellow in institutes and universities all around Europe and in the Asia-Pacific region.