From carbon cost to climate care: Greening our intensive care units.

Healthcare systems are major contributors to global greenhouse gas emissions, with intensive care units (ICUs) among the most carbon-intensive environments due to continuous energy demand, extensive reliance on single-use medical devices, and high pharmaceutical consumption. This narrative review examines the environmental footprint of ICUs, synthesising contemporary life-cycle evidence and international case studies describing feasible and clinically safe sustainability interventions in critical care. We outline practical strategies for ICU decarbonisation, including energy-efficient infrastructure, sustainable procurement, waste reduction, digital optimisation, and re-evaluation of low-value clinical practices. Importantly, many of these interventions align with established quality-improvement principles and are associated with clinical co-benefits such as reduced iatrogenic harm, improved patient comfort, and enhanced staff wellbeing. Broader policy frameworks, including the Sustainable Development Goals and national net-zero healthcare commitments, are discussed as enabling levers for system-level adoption. Greening ICUs should therefore be viewed not as a competing priority, but as an opportunity to deliver safer, more resilient, and patient-centred critical care while advancing planetary health.