“…When we were looking for a book (in 2018) to support the flipped-classroom version of the sustainability challenges course, we observed a gap in the available textbooks. Existing textbooks were either overly broad (e.g., [11], [12]) or were narrowly focused on one aspect of sustainability (e.g., [13], [14]). "Broad" textbooks appeal to a very wide audience and, therefore, have minimal technical content.…”