Climate change has become an increasingly pressing global issue, with widespread impacts not only on the environment but also on international security. First of all, the climate crisis is causing mass migration. When natural disasters, such as floods, droughts, and storms, worsen living conditions, populations are forced to leave their homes usually for safer areas. This can create tensions in host countries that may not be ready to accommodate a large influx of refugees. Second, competition for natural resources is becoming increasingly intense. Climate change directly affects the availability of clean water, fertile land and energy sources. Countries that experience a shortage of these resources have the potential to become involved in conflicts with neighboring countries. A clear example can be found in the Middle East and Africa region, where competition for clean water has increased tensions between countries. Furthermore, climate change is increasing the frequency and intensity of natural disasters, which is disrupting political and economic stability. Already vulnerable countries, often with weak governments, could face protracted humanitarian crises. This kind of instability creates opportunities for extremist and terrorist groups to emerge and develop, which in turn exacerbates international security challenges. In addition, climate change affects global health. The spread of diseases associated with extreme temperatures and changing weather patterns has occurred, which not only burdens the national health system, but also affects the country’s ability to remain in a stable condition. Disease outbreaks can damage diplomatic relations and worsen the resilience of the countries involved, creating situations that pose risks to international security. Climate change is also driving the rise of nationalism and protectionism. Countries may feel threatened by the influence of other countries in addressing climate impacts. Some may seek to protect their resources by denying access to other countries, which could exacerbate tensions between countries. These tensions have the potential to undermine the international cooperation needed to effectively address climate change. Uncertainty regarding the impact of climate change on the global economy is making many countries nervous. Countries that depend on agriculture, fishing and tourism for their livelihoods are most affected. When economies are threatened, the potential for conflict increases, presenting a major challenge to international security. Therefore, international collaboration is essential to face this threat. The importance of international cooperation in overcoming climate change cannot be ignored. Global agreements such as the Paris Agreement show how countries can work together to reduce the impacts of climate change. However, effective implementation and consistent commitment to the agreement is key to maintaining sustainable international security in an era filled with climate challenges. With all the complexities faced, it is clear that climate change is not only an environmental issue but also one of the main factors determining international security in the 21st century. Responding to these issues wisely and collaboratively will be key to creating a safer and more stable world.