The larch forests of the Republic of Sakha (Yakutia) are like no other place on Earth. Found in a region with some of the world’s largest seasonal temperature swings, these boreal forests are dominated by a deciduous conifer called Larix gmelinii. This hardy type of larch is capable of withstanding temperatures as low as -70°C (-94°F) and surviving in frozen permafrost soils—traits that have given the tree the most northerly range on the planet.
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.”
Outbreaks of large fires in Sakha have happened before, including 2004, 2010, 2013, 2019, and 2020. The 2019 and 2020 fire seasons were particularly extreme in Sakha’s tundra regions north of the Arctic Circle. As this area baked under extreme drought and heat, it experienced the two earliest and largest fire seasons on the satellite record.
In 2021, there has not been nearly as much burning north of the Arctic Circle; instead more of the fires occurred in forests farther south. “We saw a different part of Sakha burn this year,” Soja said. “But the underlying driver—droughts and heat amplified by climate change—was the same.”
NASA Earth Observatory image by Lauren Dauphin, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Adam Voiland.