The Water and weather, which is the delicate balance between evaporation and precipitation, is the primary cycle through which climate change is sensed. Scarcities of natural resources, floods, rapidly melting of glaciers along with fast sea-level rising, and storms are worsening or changing as our climate changes, with frequently fatal consequences. Freshwater accounts for only three percent of the total water on the earth, about 2/3 frozen in glaciers and glacial ice. Based on up-to-date climate estimates for the protection of water, we are at the moment passing through a challenging time, and the global population expected to surpass ten billion by 2055 would also be a challenging assignment, particularly for lower developing countries. In this research paper, we focused on some issues generally and particularly in the context of Pak-Afghan relations. Because, despite their geographical, linguistic, regional, religious, and ethnic entanglements, Pakistan and Afghanistan's bilateral ties have seen turbulence. Aside from classic security threats, like terrorism and extremism, foreign military intervention, jihadist Movements, dictatorship, and inter and intra-level wars, Pakistan and Afghanistan are confronted with a serious non-traditional security danger, namely the issue of Climate Change overpopulation.