Many potentially effective policies are ineffective or fail because implementation pathways are poorly identified, early partnerships are insufficient, and implementation and evaluation are lacking. Systems thinking and co‑production with stakeholders are also essential to delivering net zero. This theme collaborates with stakeholders to synthesise and apply knowledge from across the Hub, providing crucial evidence on how to design and implement policies so that their core net‑zero aims are achieved, health co‑benefits are maximised, unintended consequences are minimised, and trade‑offs are made explicit.