e23214 Background: Climate change is a threat to human existence. Healthcare is the 5th leading cause of CO2 emissions globally, while clinical trials generate the equivalent of half the CO2 emissions of Denmark. Consequently, both enterprises represent significant, potentially modifiable, causes of climate change. In response to this climate toxicity (PMID 36773799), CTI launched the National Green Cancer Clinical Trials Initiative in 2022. A climate charter, which was to consist of a living document of actionable areas, was commissioned by the CTI board to implement them. Methods: Carbon footprint touch points of CTI’s activity on climate change were identified such as travel, procurement, energy use, financial management. An online scoping review of existing academic and non-academic sustainability initiatives, funding agency and national policy documents, peer reviewed and grey literature sources was conducted using the terms climate change and sustainability. Action points were categorised and collated. No exemplar climate charters for clinical trial organisations were identified in the search. Results: 5 pillars of interaction with sustainability initiatives were evident. These were education, engagement, empowerment, embedding, and emphasising. These pillars related to 8 themes for climate smart involvement by CTI staff and members. Personal commitment to sustainability at an individual level eg dietary choices, EU climate pact participation. Trial design and management eg sustainability assessment & integration into protocols Recycling and waste management at central office and sites. Energy and water use eg optimise computing infrastructure, prioritise low carbon sources. Procurement and contracts eg promote green purchasing, integrate environmental and social sustainability clauses in contracts, sustainability assessment of financial services including pensions Meetings and conferences eg prioritising virtual meetings, select conference venues and accommodation with environmental certs. Commuting and business travel. Outreach eg, to University partners, trainees, network with Green Trial groups. Conclusions: The climate charter provides a structure to facilitate sustainability integration at CTI. This living document registers existing activities, highlights areas for engagement, facilitates horizon scanning and outreach to emerging initiatives, empowers staff , and demonstrates an organisational commitment to climate smart, clinical trial conduct.