Rapid Greening Across Arctic Tundra Studied via NASA Satellites – “Really a Bellwether of Global Climatic Change”

The study is the first to measure vegetation changes across the Arctic tundra, from Alaska and Canada to Siberia, using satellite data from Landsat, a joint mission of NASA and the U.S. Geological Survey.
Credit: Logan Berner, Northern Arizona University

International team of researchers finds the region has become greener as warmer air and soil temperatures lead to increased plant growth.

As Arctic summers warm, Earth’s northern landscapes are changing. Using satellite images to track global tundra ecosystems over decades, a team of researchers finds the region has become greener as warmer air and soil temperatures lead to increased plant growth.

“The Arctic tundra is one of the coldest biomes on Earth, and it’s also one of the most rapidly warming,” said Logan Berner, assistant research professor with Northern Arizona University’s School of Informatics, Computing, and Cyber Systems (SICCS), who led the research in collaboration with scientists at eight other institutions in the U.S., Canada, Finland and the United Kingdom. “This Arctic greening we see is really a bellwether of global climatic change — it’s this biome-scale response to rising air temperatures.”

The study, published this week in Nature Communications, is the first to measure vegetation changes across the Arctic tundra, from Alaska and Canada to Siberia, using satellite data from Landsat, a joint mission of NASA and the U.S. Geological Survey. Scientists use Landsat data to determine how much actively growing vegetation is on the ground — greening can represent plants growing more, becoming denser or shrubs encroaching on typical tundra grasses and moss.

When the tundra vegetation changes, it impacts not only the wildlife that depend on certain plants, but also the people who live in the region and depend on local ecosystems for food. While active plants will absorb more carbon from the atmosphere, the warming temperatures are also thawing permafrost, releasing greenhouse gasses. The research is part NASA’s Arctic Boreal Vulnerability Experiment (ABoVE), which aims to better understand how ecosystems are responding in these warming environments and its broader implications.

Berner and his colleagues, including SICCS faculty Patrick Jantz and Scott Goetz along with postdoctoral researcher Richard Massey and research associate Patrick Burns, used the Landsat data and additional calculations to estimate the peak greenness for a given year for each of 50,000 randomly selected sites across the tundra. Between 1985 and 2016, about 38 percent of the tundra sites across Alaska, Canada and western Eurasia showed greening. Only 3 percent showed the opposite browning effect, which would mean fewer actively growing plants.

To include eastern Eurasian sites, the team compared data starting in 2000, which was when Landsat satellites began collecting regular images of that region. With this global view, 22 percent of sites greened between 2000 and 2016, while 4 percent browned.

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