In light of not only the scale of climate finance needs, but also the type of public finance instruments needed to leverage private flows, the importance of more connected coordination and collaboration by international public climate finance actors is crucial. Systems thinking approaches support the recognition of the effects of existing and new actors on scaling overall flows and their direction of travel, as well as support the collective optimisation of public finance interventions to achieve the scale needed – helping to understand not only the specific niche of each actor, but also how actors can most effectively coordinate and collaborate to achieve enduring impact.