This chapter considers what Green Human Resource Management (GHRM) is, and then what GHRM research could possibly do to indirectly mitigate climate change impacts. Critical Marxist-inspired work by P. Hampton has researched worker and trade union roles in building 'climate solidarity'. The upside of using Ability–Motivation–Opportunity (AMO) theory in GHRM research is that it has a practical relevance in guiding organizations, managers and practitioners forward on what workplace GHRM interventions they might possibly consider implementing to help combat climate change. However, using AMO theory in GHRM also has constraints, as AMO theory can seem somewhat instrumental, pro-managerial and arguably Orwellian at first sight too, because it looks to change staff behaviour towards increasing concern for the external environment. In environmental psychology, a major review reveals three major pro-environmental workplace behaviour theoretical frameworks being used: the theory of reasoned action, the theory of planned behaviour and value-belief-norm theory.