This is the first study to measure the 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.
The study was published recently in Nature Communications. The study might have us believe this is not good news, because climate change good news is forbidden among leftists fearing climate change. But it is good news, if you live in reality!
Greening can represent plants growing more, becoming denser or, shrubs encroaching on typical tundra grasses and moss. The research is part NASA's Arctic Boreal Vulnerability Experiment (ABoVE), which aims to better understand how ecosystems are responding in the warming environment.
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."
Berner and 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.
"Landsat is key is for these kinds of measurements because it gathers data on a much finer scale than what was previously used," said NAU professor Goetz, who contributed to the study and leads the ABoVE science team. 