Modern ecological economics emerged in opposition to mainstream economics as a scientific approach with many key heterodox features. Among these are an open systems perspective, transdisciplinarity, and radical criticism of the conventional representation of economic process. The term “ecological economics” was included internationally in the second edition (2008) of The New Palgrave Dictionary of Economics, the most prestigious and widely used dictionary of economics. In our view, however, the entry does little to facilitate understanding of the heterodox features, and theoretical and methodological controversies that have developed in ecological economics over the last two decades.