This article examines the contributions that partnerships make to interaction management. Our conceptualization of interaction management builds on earlier contributions to the literature on regimes and governance. The article focuses on the interactions among the biodiversity and climate change governance systems, since these systems interact intensively on the issues of biofuels and forests (Reducing Emissions from Deforestation and Forest Degradation—REDD+). The article shows that seven partnerships actively manage the interactions by fulfilling several critical interaction management functions. Their main contributions include creating markets for sustainable biofuels through the development of certification standards and creating markets for “multiple benefit” REDD+. Although the partnerships improve interactions on case-by-case bases, they fail to fundamentally improve existing interactions between the biodiversity and climate change governance systems. Improved meta-governance and public-private interplay are necessary for more effective interaction management and, more generally, the effective governance of sustainable development.