In summer 2021, huge fires raged through these larch forests for months. During Sakha’s most severe fire season in decades, more than 8.4 million hectares of forests burned. “That’s an amazing amount—nearly four times the average,” said Amber Soja, a NASA and National Institute of Aerospace associate research fellow who has conducted field research in the region. It’s also record-breaking. More forest area burned in Sakha than in any year since the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite began collecting data in 2000.
In the false-color satellite image above, burned areas appear dark brown. Unburned areas are green. Patches of green within burn scars are fire refugia—areas within fire perimeters that were unburned or only lightly burned. The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured the image on September 10, 2021.
For a sense of scale, Sakha is almost twice as large as Alaska, the largest U.S. state, and five times larger than Madagascar. “What happens in Sakha, and in boreal forests more broadly, matters tremendously,” said Soja. “Boreal forests store more carbon than any other type of forest in the world—even more than tropical rainforests.”
Larix gmelinii drops its needles each winter, but the weather is so cold that there are few decomposers (bacteria, fungi, invertebrates) around to break them down. That means tremendous amounts of organic carbon end up accumulating in soils over time.
“Many of the fires here burn for a long time—weeks even months. Some have burned the same areas in multiple years,” Soja explained. “These fires aren’t just spreading across the landscape, they’re also burning down. They’re thawing permafrost, burning through layers of peat in some areas, and releasing stored carbon and methane that has built up over millennia.”