There are growing concerns that climate change will lead to large-scale population displacements and migrations in coming decades. Many security scholars worry that these may in turn contribute to violence and conflict in the most vulnerable regions. Are these concerns supported by scientific evidence? And if so, what options are available to concerned policymakers? In response to these and other questions, this report reviews the available scholarly reporting on climate change, migration and security and describes the legal and policy challenges facing the international community.