Thanks to warming winters and thawing permafrost, Arctic soil microbes are churning out carbon dioxide well after the end of the growing season ends. This extra source of atmospheric carbon may accelerate a regional warming trend that is already twice as fast as the global average.
As the Arctic has warmed over the past three decades, satellites reveal it has also grown greener overall. But in recent years, the tundra appears to be “browning down.”
Since observations began in 1982, Arctic-wide tundra vegetation productivity has increased. In North America, the rate of greening has accelerated since 2005.