Today, there is no country known as the roof of the world. However, the Chang Tang, also known as the Qinghai-Tibetan Plateau in Tibet was given this title. As it accounted for most of Tibet's total area, Tibet too got this title. As Tibet is no longer an independent country but has been absorbed by communist China since the 1960's, it would be incorrect to say that either Tibet or China is the "roof of the world" So for all practical purposes the Chang Tang plateau alone is considered to be the "roof of the world". This vast, elevated plateau occupies an area of approximately 2.5 million square kilometers and has an average elevation of 4,500 m. It is the largest highest plateau in the world. Unfortunately, it faces extremely serious ecological threats that could ruin the environment and more importantly the melting glaciers could mean the death of millions of people in the future. Anonymous