Complex sentence: At 3,425,804 square kilometers, the combined area of the Nordic countries would form the 7th-largest country in the world; though uninhabitable icecaps and glaciers comprise about half of this area, mostly in Greenland.
Split into simpler sentences: At 3,425,804 square kilometers, the combined area of the Nordic countries would form the 7th-largest country in the world. Uninhabitable icecaps and glaciers comprise about half of this area, mostly in Greenland.