Organizations are rapidly adopting to digital technologies as an integral part of their sustainability strategies for achieving net-zero carbon targets, though a significant progress is made in areas such as energy monitoring and operational efficiency, human capital as a direct contributor to carbon reduction goals is an important factor that often remain overlooked. To evaluate the performance of the human capital in an IoT-enabled environment which is designed to support a zero-carbon future, the chapter proposes a conceptual framework, that has Smart Workforce Metrics (SWMs) at its core which utilizes variety of real time data ranging from occupancy sensors and energy-tracking wearables to digital mobility records in an IoT enabled ecosystem, this will hep in quantifying the environmental footprint of employees at the individual, team, and organizational levels. The framework draws from key theoretical perspectives including Green Human Resource Management, Socio-technical Systems theory, and Performance Management. By merging data-driven insights with behavioural analysis, the model establishes a multi-dimensional approach that directly connects employee actions to sustainability outcomes. Ultimately, the proposed model contributes to the ongoing discussion on linking human capital development with environmental accountability. It does so by embedding carbon-sensitive key performance indicators (KPIs) into performance management systems, thereby ensuring that workforce evaluation and sustainability goals are aligned. The chapter also discusses ethical considerations in IoT-based monitoring, the potential for digital ESG dashboards, and the strategic implications for HR leaders and policymakers aiming to operationalize sustainability goals. The chapter addresses a key gap in current literature by unifying digital performance tracking and workforce sustainability metrics and by offering a forward-looking tool for smart, resilient, and responsible organizations.