The Issue
Healthcare plays a vital role in improving population wellbeing – but it also carries a considerable environmental cost. Globally, healthcare services account for between 1–5% of total environmental impacts. In England alone, the NHS is responsible for around 4% of the nation’s total carbon emissions.
Despite the urgent need to reduce carbon output, it has not always been clear which existing interventions are effective in reducing emissions, where evidence already exists and, importantly, where the gaps are. Without this information, there is a risk that future research and policy initiatives may duplicate existing efforts or miss opportunities to implement carbon-saving approaches.
What We Did
To address this challenge, PenARC supported researchers carried out a systematic review and evidence and gap map of low-carbon interventions across secondary healthcare. This included a structured search and assessment of published research on:
- Carbon-reducing interventions used in diagnosis, treatment and follow-up;
- Their effects on carbon emissions;
- Any impact on patient safety, quality of care and associated costs.
The review team analysed interventions across different clinical pathways and service areas, noting where robust data existed and where evidence was currently limited or absent.
A visual, user-friendly online evidence map was developed to allow commissioners, researchers and policymakers to identify:
- Where strong evidence is available;
- Where more research is urgently needed to inform decision-making.
This was accompanied by a detailed report and briefing paper summarising key findings and highlighting priority areas for future research.
The Impact
- To date (September 2025), the evidence map has already received over 320 unique visitors, demonstrating early engagement from policy and research communities, and the report has been downloaded over 260 times.
- It has been used by the NIHR and national stakeholders to shape prioritisation discussions on future funding for net zero research in healthcare.
- The work ensures that future studies are directed towards evidence gaps, supporting more effective use of research funding.
- It provides commissioners and policymakers with a key resource to inform decisions on the introduction and scale-up of low carbon interventions within the NHS.
- Ultimately, the mapping exercise contributes to national efforts to meet the Climate Change Act 2050 target of net-zero emissions by providing decision-makers with accessible evidence on what works – and where more evidence is needed.
This work was carried out by the Exeter PRP Evidence Review Facility. Core members of the Exeter PRP Evidence Review Facility are supported by PenARC.
Last Updated September 2025.