In particular, the effects of climate change may intensify economic, political, and geopolitical crises arising from food and water scarcity in many places around the world. As a result, situations of massive migrations and regional instability could become aggravated, and even lead to new armed conflicts. Likewise, global warming will have direct repercussions in Spain, because it will cause more extreme and frequent adverse weather events, droughts, heatwaves, floods, water scarcity, and harm to biodiversity.

Ecological transition: Climate change has a negative impact on human life and well-being. Its effects include a rise in the number of extreme weather events, the degradation of land and marine ecosystems, desertification, the increased incidence and frequency of heatwaves, droughts, the reduction of water availability, Saharan dust intrusions, forest fires, floods, and biodiversity loss. These harmful effects could lead to greater competition for resources and to an increase in migration movements from areas more exposed to the detrimental consequences of climate change.

Irregular migratory flows - Economic, social, and environmental factors, as well as political instability, poverty, and conflict will continue to influence global migratory trends.

The effects of climate change constitute one of the most pressing threats to national security due to their cross-cutting impacts in spheres as diverse as energy security, emergencies and disasters, conflicts, and the displacement of persons due to environmental degradation and natural disasters. In particular, a significant security nexus lies in potential conflicts deriving from the effects of climate change in the most vulnerable countries. To this end, the National Climate Change Adaptation Plan advocates preventive development assistance policies, which focus on building resilience through early detection. This requires identifying those places most vulnerable to climate change in order to prioritize action.