Authors: Dellmuth Lisa Maria, Gustafsson Maria-Therese, Kural Ece.

Climate change adaptation is increasingly perceived as a global and interconnected policy challenge among practitioners and academics, making localized solutions insufficient. In parallel to this trend, a growing number of international organizations that do not have climate as their core mandates link adaptation to various issue areas, such as energy, health, and conflict resolution. Yet we still know little about how and why international organizations respond to adaptation challenges. This article develops an innovative theoretical framework to understand the factors that influence the governance responses of international organizations to adaptation challenges in the context of their respective issue areas. Our analysis reveals that there are three main and interrelated factors influencing international governance responses: problem complexity, institutional fragmentation, and fiscal pressures. We examine our framework by drawing on of two sources of data: first, a yearly large-n dataset at the level of fourteen international organizations from 2007 to 2017 created on the basis of official documents; and second, in-depth case studies of three UN agencies central in addressing three prominent issue linkages: climate-conflict, climate-health, and climate-migration. We conclude by sketching broader implications for the theory and practice of global adaptation governance.