The Impact of Green Human Resource Management on Employee Sustainable Behaviour: Explaining the Sustainability Implementation Gap

Organizations increasingly adopt Green Human Resource Management (GHRM) to translate environmental strategy into employee action, yet formal adoption of green practices does not reliably produce sustainable behaviour on the ground. This implementation gap is theoretically underspecified: GHRM is known to shape employees' green psychological climate, and that climate is known to predict green behaviour, but why the translation from perception to action is inconsistent across studies remains unexplained. This paper develops an integrated theoretical model to close that gap. Drawing on signaling theory to explain how GHRM practices are interpreted as credible cues, and climate-as-social-process theory to explain how such cues become a climate that does, or does not, convert into action, the paper proposes Leadership Authenticity as the missing leadership-level boundary condition, with Green Psychological Climate as the mediating mechanism between GHRM and Employee Sustainable Behaviour. Four hypotheses and a refined conceptual framework are developed, directly confronting closely related recent studies that test structurally similar leadership-moderator logic with different constructs. The model reframes the field's central question from whether GHRM produces sustainable behaviour to how, and under what leadership condition, it does so, offering practitioners a credibility-based diagnostic for why green policies fail to translate into action.