Background: Due to the climate crisis, it is increasingly evident that countries will have to decarbonize. Healthcare, which has a large carbon footprint and uses vast quantities of resources, will have to undergo significant transformation. In this research, we sought the ideas of leading thinkers in the field, to address the question of how health systems can provide high-quality care in a carbon-constrained world. Methods: Semi-structured, qualitative in-depth interviews with 15 healthcare thought leaders from Australia, the UK, the USA and New Zealand. The interviews were transcribed and analysed by matrix display and thematic analysis. Results: ‘Green’ initiatives such as improving energy efficiency and implementing travel plans will be insufficient to achieve the scale of decarbonization required. According to the thought leaders in our study, it is likely that greater carbon and resource savings will come from thinking much more broadly about innovative models of care and using ‘new’ sources of ‘value’ such as ‘people’ and ‘relationships’. Conclusions: Using human resources and human interactions as low-carbon sources of value in healthcare are promising models.