Theory of change is a concrete manifestation of the principle of knowledge co-production, of particular interest when designing projects to support socio environmental transitions. It seeks to clearly establish the different visions of change in play, along with the obstacles and opportunities they face, and thence to co-construct a shared vision conducive to a unified plan of action. toc transforms knowledge into action, forging connections between different actors, sectors and levels of intervention. By breaking down silos, it can make solutions feel tangible. In doing so it paves the way for large-scale change, bringing political decision-makers on board via local, national and regional networks