Northern permafrost region emits more greenhouse gases than it captures, study finds
Permafrost underlies about 14 million square kilometers of land in and around the Arctic. The top 3 meters contain an estimated 1 trillion metric tons of carbon and 55 billion metric tons of nitrogen. Historically, the northern permafrost region has been a sink for carbon, as frozen soils inhibit microbial decomposition. But rising temperatures contribute to thawing permafrost and enhance the biogeochemical activities that exacerbate climate change by releasing greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).