A forest larger than the Amazon
The Russian Taiga, also known as the boreal forest, is the single largest forested region on Earth. Spanning approximately 12 million square kilometers, it is larger than the Amazon rainforest and contains over half of the world's coniferous trees. This immense biome is dominated by a few hardy tree species adapted to the extreme climate, primarily larches, spruces, and pines. In Eastern Siberia, the landscape is a vast larch forest, with species like the Dahurian larch tolerating the coldest winters in the Northern Hemisphere.
The taiga's importance is its carbon reservoir. The northern circumpolar permafrost region holds an estimated 1,460 to 1,600 billion metric tons of organic carbon, which is roughly double the amount currently in Earth's atmosphere. Unlike tropical forests that store most of their carbon in living biomass, the taiga's real storage capacity is in its soil. The cold, often frozen ground slows decomposition to a crawl, allowing thousands of years of dead organic matter—plants, animals, and microbes—to accumulate in the soil and permafrost. This subterranean carbon vault contains far more carbon than the trees standing above it.
The thaw and burn cycle
This vast carbon store is becoming unstable. The Arctic is warming more than twice as fast as the global average, causing the permafrost to thaw. As the ground thaws, microbes begin to break down the ancient organic material, releasing carbon dioxide and methane. Methane is a potent greenhouse gas, trapping heat over 25 times more effectively than carbon dioxide over a 100-year period. This release of greenhouse gases creates a dangerous positive feedback loop: warming thaws the permafrost, which releases more greenhouse gases, which in turn causes more warming.
Wildfires are accelerating this process. Hotter and drier conditions lead to more frequent and intense fires. Some recent fire seasons have been extraordinary; in 2020, wildfires in Siberia released an estimated 350 megatons of carbon. A phenomenon known as "zombie fires" has become more common, where fires smolder underground in carbon-rich peat all winter, surviving under the snow to re-emerge in the spring. These overwintering fires can transform a single fire season into a multi-year event, continuously releasing ancient carbon into the atmosphere and making it harder for the forest to regenerate.