This chapter discusses some less-examined prospects regarding future research ideas in Green Human Resource Management (GHRM), and possible links between GHRM and building more sustainable workforces. Future research on Green leadership could compare the relative impacts of environmentally focused and more general transformational leadership over different cultural and organizational conditions, and include environmental focus as a control to exclude potential threats linked to demand characteristics. Future research on green psychological climate could move away from using participant self-reported employee green behavior (EGB) to more objective 'other' supervisor or peer-ratings, observations, and archival data, to develop theory and test hypotheses on boundary conditions. The chapter discusses links between GHRM and sustainability in general, and connecting GHRM to more sustainable workforces in particular. Studies investigating eco-initiatives and workplace social exchange networks may also assess the usefulness of social exchange variables, such as trust, justice, and the psychological contract, to better comprehend underlying reciprocity processes in environmental sustainability.