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Greener Trials – decarbonising the delivery of health and social care research


Whilst clinical trials are critical to identifying effective and safe treatments, they also have a significant environmental impact. Despite the first publication of a trial’s carbon footprint 16 years ago, there has been little action to consciously reduce carbon consumption of clinical trials, while the urgency of the threat from the climate crisis has increased exponentially. Approximately 38,000 new trials were registered globally on in 2022, with estimated carbon footprints of ~80 to over 2000 tonnes CO2 for a single trial. Clearly, clinical trials are an important but underexplored area to target for decarbonisation, whilst protecting health.

The ICR recognises the importance of fostering innovation to face global sustainability issues and at ICR-CTSU we are committed to reducing the environmental impact of trials and reducing the carbon footprint of our research.

We are part of the ICR’s Sustainability Advisory Steering Group, helping lead the development and implementation of the ICR’s sustainability strategy. We also contribute to the ICR’s ActNow sustainability working group which works across the ICR to help deliver initiatives and projects aligned with our sustainability strategy.

Current work

A collaboration between the Institute of Cancer Research – Clinical Trials and Statistics Unit (ICR-CTSU) and the University of Liverpool supported through NIHR funding has brought renewed activity and interest in this area through the development of the first iteration of a method and guidance to carbon footprint publicly funded clinical trials (doi:10.21203/ The work has been conducted in collaboration with other UKCRC Clinical Trials Units and the Sustainable Healthcare Coalition’s Low Carbon Clinical Trials Group. If you are interested in finding out more about carbon footprinting one of your trials, please contact the ICR-CTSU Carbon in Clinical Trials Team on

Recognising the growing interest and support for this area of work, the NIHR MRC Trials Methodology Research Partnership recently established the Greener Trials group, lead by ICR-CTSU’s Assistant Operations Director, Lisa Fox. The multi-disciplinary group aims to develop the tools required to facilitate lower carbon clinical trials; work on a free online, publicly available eco-design tool for non-commercial research; to develop and disseminate greener research practice and facilitate collaboration between stakeholders to set the research agenda and drive the paradigm shift to lower carbon clinical trials. More details are available at:

The ICR-CTSU is committed to identifying ways to reduce the environmental impact of our work. In addition to the trial conduct and methodology work described above and engaging with the sustainability initiatives of the ICR as our host institution, we have established the ICR-CTSU Sustainability Working Group to consider how best we can apply local, national and sector-specific initiatives to our day to day work. To date our group have introduced carbon footprinting of new ICR-CTSU trials at the funding application stage to try and inform lower carbon trial design, improved waste management, reduced single-use plastics, introduced various re-cycling initiatives and energy saving measures, engaged with sustainability initiatives such The Freezer Challenge and My Green Lab Ambassador Program and initiated projects to reduce consumable waste in our sample kit collections.

We also plan to work towards a de-centralised approach to clinical trials by, for example, employing remote and e-consent practices to reduce unnecessary patient travel and remote monitoring techniques to reduce ICR-CTSU team visits to participating sites.

To contact the ICR-CTSU Sustainability Working Group please email the team using