Global environmental changes present unprecedented challenges to humans and the ecosystems upon which they depend. The need for interdisciplinary approaches to solve such multidimensional challenges is clear, however less clear is whether current attempts to cross disciplinary boundaries are succeeding. Indeed, efforts to further interdisciplinary approaches remain hampered by failures in assessing their scope and success. Here a set of measures examined the interdisciplinarity of the environmental sciences and tested two literature-based hypotheses: (1) newer and larger disciplines are more interdisciplinary; and (2) interdisciplinary research has lower impact factors than its counterparts. In addition, network analysis was used to map interdisciplinarity and determine the relative extent to which environmental science disciplines draw on alternative disciplinary perspectives. Contrary to expectations, age and size of a discipline had no effect on measures of interdisciplinarity for papers published in 2006, though metrics indicated larger articles and journals were more interdisciplinary. In addition, interdisciplinary research had a greater impact factor than its more strictly disciplinary peers. Network analysis revealed disciplines acting as ‘interdisciplinary frontiers’, bridging critical gaps between otherwise disparate subject areas. Whilst interdisciplinarity is complex, a combination of diversity metrics and network analysis provides valuable preliminary insights for interdisciplinary environmental research policy. The successful promotion of interdisciplinarity is needed to help dispel commonly perceived barriers to interdisciplinarity and create opportunities for such work by increasing the space available for different disciplines to encounter each other. In particular, the networks presented highlight the importance of considering disciplinary functioning within the wider context, to ensure maximum benefit to the scientific community as a whole.