Most of the refugees arriving in Europe are fleeing civil war and unrest. However, it is important to recognise how the second-order effects of climate change—which can undermine agriculture and increase competition for water and food resources—are contributing to instability and decisions to migrate. While migratory decisions are complex, climate change is an increasingly important contributing factor: it is threatening humanity’s shared interests and collective security in many parts of the world. The cumulative effects of these trends have serious implications for the stability of nations that lack sufficient resources, good governance and the resilience to respond. While there is a need for greater understanding of the detailed causes of migration, as well as the associated economic and political instability, a growing body of evidence links climate change, migration and conflict in troubling ways.This article was originally published in Publishing House Springer.