What portions of east Asia relatively unpopulated?

* The Tibetan Plateau: This vast, high-altitude region is located in southwestern China and covers an area of about 2.5 million square kilometers. Its average elevation is over 4,500 meters, and the climate is cold and dry. The population of the Tibetan Plateau is relatively sparse, with an average density of less than 1 person per square kilometer.

* The Gobi Desert: This large desert is located in northern China and Mongolia. It covers an area of about 1.3 million square kilometers. The climate of the Gobi Desert is extremely harsh, with hot summers and cold winters. The average annual precipitation is very low, and the vegetation is sparse. The population of the Gobi Desert is very small, with an average density of less than 1 person per square kilometer.

* The Taklamakan Desert: This large desert is located in northwestern China. It covers an area of about 337,000 square kilometers. The climate of the Taklamakan Desert is extremely hot and dry, with average summer temperatures exceeding 40 degrees Celsius. The average annual precipitation is very low, and the vegetation is sparse. The population of the Taklamakan Desert is very small, with an average density of less than 1 person per square kilometer.

* The Siberian Taiga: This vast coniferous forest covers much of eastern Russia. It is the largest forest in the world, covering an area of about 7 million square kilometers. The climate of the Siberian Taiga is cold and humid, with long, harsh winters. The average annual precipitation is moderate, and the vegetation is dense. The population of the Siberian Taiga is relatively sparse, with an average density of less than 1 person per square kilometer.