Paragraph 12 of the revised International Code of Medical Ethics (ICoME) states that ‘the physician should strive to practise medicine in ways that are environmentally sustainable with a view to minimising environmental health risks to current and future generations.’1 This emphasis on environmental sustainability is in line with popular discourse as well growing scholarly attention in medical ethics for healthcare’s contribution to climate change. Recent research analyses, for instance, the ‘greening’ of informed consent and related bioethical principles.2 3 It is (...) unclear what the duty of practising sustainable healthcare means at the level of doctor–patient interaction. Parsa-Parsi et al flag the potential conflict in the ICoME’s provisions if ‘the actions of physicians are influenced by environmental considerations to the detriment of patients’ (p. 2), noting that the ICoME does not provide a handhold to improve understanding of such tensions. The code ‘does not go into extensive detail, does not include comprehensive explanations nor any rules or guidance on how to reconcile its principles when they conflict’ (p. 4). For Parsa-Parsi et al, not codes, but textbooks have a crucial role to play in resolving this conflict. It is rife that professional codes can lead to internal inconsistencies and …. (shrink)