In this new flagship report, WBGU summarizes the state-of-the-art of science on the subject of Climate Change as a Security Risk. It is based on the findings of research into environmental conflicts, the causes of war, and of climate impact research. It appraises past experience but also ventures to cast a glance far into the future in order to assess the likely impacts of climate change on societies, nation-states, regions and the international system. The core message of this report is that without resolute counteraction, climate change will overstretch many societies" adaptive capacities. In some regions of the world, this may result in internal destabilization processes and state failure with diffuse conflict structures, inter-state conflicts and an overstretching of the international system. Classic security policy cannot respond adequately to these new threats to international stability. Climate policy and strategies for adaptation to climate change are thus...