The taiga of Siberia covers 6.8 million sq km and represents nearly 19% of the world's forest area and possibly 25% of the world's forest volume. About 4,000 sq km of the Russian taiga are logged annually, and nearly an equal area is burned, with perhaps half of the burned area representing essentially destructive fires of human origin. Logging has been concentrated in European Russia, the Siberian Far East, and the railroad corridors between. Large areas, perhaps exceeding 2 million ha, of the Russian taiga have been killed by air pollution near Norilsk and the Kola Peninsula.