BACKGROUND:
Global healthcare sustainability often focuses on technical "greening" of facilities, yet the most significant environmental determinant is the overarching management model. A hospital-centric, reactive system is inherently carbon-intensive due to its reliance on complex, energy-heavy diagnostic tools often utilized in secondary and tertiary centers. This session argues that a fundamental shift toward a Primary Health Care (PHC)-led model, focusing on early detection and simpler investigations, offers a lower-intensity, high-value pathway. We explore how preventive stewardship can reduce the sector’s 5% global emissions while preserving patient safety.

METHODS:
Utilizing a Systemic Comparative Analysis, this session contrasts two health systems architectures. We model the lifecycle carbon footprint of clinical pathways within a "Reactive-Hospital" system against a "Preventive-PHC" system. The evaluation examines the "Diagnostic Intensity of Care," specifically comparing high-resource tertiary diagnostics against early detection protocols in community settings. The methodology focuses on exploring how public health policy can incentivize the use of simplified, low-carbon investigations for preventable diseases that deliver equivalent safety outcomes.

RESULTS:
Findings indicate that systems prioritizing PHC-led early detection achieve a "Carbon Dividend" by bypassing the energy-intensive cascades of hospital-based care. The results demonstrate that "low-tech" community-based monitoring for preventable illnesses yields superior safety outcomes by preventing acute crises. We identify that "Diagnostic Over-Engineering" in tertiary centers is a primary driver of environmental impact, whereas PHC-integrated stewardship provides a scalable path to decarbonization through reduced clinical redundancy and energy-optimized diagnostics.

CONCLUSIONS:
Decarbonization is a prerequisite for planetary health, but it can’t be achieved within a hospital-centric vacuum. A shift toward early detection and simplified investigations within a PHC-led model is essential for sustainable health governance. Public health leaders must recognize that preserving patient safety does not require high-carbon complexity. To "walk the talk," we must institutionalize PHC as the primary engine for both health equity and environmental resilience.