The Hippocratic Oath begins with a simple, profound directive: ‘First, do no harm.’ Yet, for decades, the global healthcare sector has been locked in a quiet paradox. While doctors work tirelessly to treat illnesses, heat exhaustion and vector-borne diseases, the very buildings they inhabit are contributing to the climate crisis that fuels these ailments. As of 2026, the healthcare industry is responsible for approximately 5% of global greenhouse gas emissions. If the sector were a country, it would be the fifth-largest polluter on the planet [1]. To truly honour the oath of ‘no harm’, healthcare must move beyond the passive goal of carbon neutrality and embrace the ambitious frontier of carbon-negative healthcare.
The irony of modern medicine
Hospitals are, by design, resource-intensive machines. They operate 24/7, requiring massive amounts of energy for climate control, sterilisation and life-saving equipment. However, the carbon footprint of a hospital extends far beyond its utility bill. The industry’s emissions are typically categorised into three scopes:
- Scope 1: Direct emissions from hospital-owned sources, such as onsite boilers and medical gases like C3F8, with a global warming potential 8900 times (see Eye News Aug-Sep ‘25 issue)
- Scope 2: Indirect emissions from the generation of purchased electricity
- Scope 3: This includes the upstream (entire supply chain: the manufacturing of pharmaceuticals, the disposal of single-use plastics) and downstream (the carbon cost of patient and staff travel).
When we look at this data, it becomes clear that ‘doing less harm’ (neutrality) isn't enough. To heal the planet – and by extension, its inhabitants – healthcare must become restorative.
From neutral to negative: The strategic shift
Carbon-negative healthcare implies that a health system removes more carbon from the atmosphere than it emits. This isn't just about buying ‘offsets’ or planting trees in a distant country; it’s about rethinking the medical infrastructure from the ground up.
1. Circularity and ‘green’ surgery
In 2026, we are seeing a massive shift toward the circular economy in surgical suites. Historically, surgical trays were filled with instruments that were often never used. Tray rationalisation and the return to high-quality, reusable medical devices are slashing Scope 3 emissions (see Eye News Oct-Nov ‘25 issue for the Leeds experience, for example). Partnering with surgical manufacturers can create a circular economy where old plastic speculums and vials are chemically recycled back into medical-grade polymers. Switching from nitrous oxide to total intravenous anaesthesia is happening across the NHS.
2. The hospital as a carbon sink
Hospitals are now being constructed with carbon-sequestering materials, such as cross-laminated timber or bio-concrete that absorbs as it cures. On the operational side, integrated direct air capture systems are being trialled in hospital HVAC units, literally scrubbing the air clean as it enters and exits the building [2].
3. Regenerative estates and nature-based solutions
Healthcare providers are uniquely positioned to lead in biophilic design. By transforming vast hospital parking lots and sterile lawns into diverse healing forests and wetlands, hospitals do more than just sequester carbon. They provide green prescriptions – proven clinical interventions where patient recovery times are shortened simply by proximity to nature [3]. In this model, the hospital grounds function as both a carbon sponge and a therapeutic tool.
4. Digital health as decarbonisation
Perhaps the most potent tool for a carbon-negative future is prevention. The most carbon-efficient patient is the one who never needs to be admitted. By leveraging AI-driven predictive analytics and telemedicine – which saw a permanent integration following the mid-2020s tech boom – systems can manage chronic conditions remotely. This eliminates the carbon cost of travel and the intensive resource consumption of inpatient stays [4].
The new bottom line
Transitioning to a carbon-negative model is not merely an environmental preference; it is a clinical necessity. By moving toward carbon negativity, healthcare shifts from being a contributor to global illness to a literal engine of global recovery. The prescription for the future is clear: healthcare must not just do no harm; it must actively do good.
References
- Or Z, Seppänen A-V. The role of the health sector in tackling climate change: A narrative review. Health Policy 2024;143:105053.
- López LR, Dessì P, Cabrera-Codony A, et al. Indoor CO2 direct air capture and utilization: Key strategies towards carbon neutrality. Clean Eng Technol 2024;20: 100746.
- Guidolin K, Jung F, Hunter S, et al. The influence of exposure to nature on inpatient hospital stays: A scoping review. HERD 2024;17(2):360–75.
- https://www.england.nhs.uk/long-read/artificial-intelligence-ai-and-machine-learning/ [Link last accessed April 2026]
