title: Taiga
context: Taiga is the world's second-largest land biome, after deserts and xeric shrublands, covering 17×10^6km2 (6.6×10^6sqmi) or 11.5% of the land area of the Earth.[4] The largest areas are located in Russia and Canada. The taiga is the terrestrial biome with the lowest annual average temperatures after the tundra and permanent ice caps. Extreme winter minimums in the northern taiga are typically lower than those of the tundra. The lowest reliably recorded temperatures in the Northern Hemisphere were recorded in the taiga of northeastern Russia. The taiga or boreal forest has a subarctic climate with very large temperature range between seasons, but the long and cold winter is the dominant feature. This climate is classified as Dfc, Dwc, Dsc, Dfd and Dwd in the Köppen climate classification scheme,[5] meaning that the short summer (24h average 10°C (50°F) or more) lasts 1–3 months and always less than 4 months. In Siberian taiga the average temperature of the coldest month is between −6°C (21°F) and −50°C (−58°F).[6] There are also some much smaller areas grading towards the oceanic Cfc climate with milder winters, whilst the extreme south and (in Eurasia) west of the taiga reaches into humid continental climates (Dfb, Dwb) with longer summers. The mean annual temperature generally varies from −5°C to 5°C (23°F to 41°F),[7] but there are taiga areas in eastern Siberia and interior Alaska-Yukon where the mean annual reaches down to −10°C (14°F).[8][9] According to some sources, the boreal forest grades into a temperate mixed forest when mean annual temperature reaches about 3°C (37°F).[10] Discontinuous permafrost is found in areas with mean annual temperature below 0°C, whilst in the Dfd and Dwd climate zones continuous permafrost occurs and restricts growth to very shallow-rooted trees like Siberian larch. The winters, with average temperatures below freezing, last five to seven months. Temperatures vary from −54°C to 30°C (−65°F to 86°F) throughout the whole year. The summers, while short, are generally warm and humid. In much of the taiga, −20°C (−4°F) would be a typical winter day temperature and 18°C (64°F) an average summer day.
question: How many miles does the Taiga cover?
answers: (6.6×10^6