The Arctic is becoming greener and more lush, revealed recent satellite images of Alaska’s Yukon Delta, and it’s very bad news for the polar region and beyond.
The images, captured by the US Geological Survey’s (USGS) Landsat 8 satellite on 29 May, showed extensive greenery in former tundra conditions - yet further evidence of global temperature rise.
Dr Uma Bhatt, an atmospheric science professor at University of Alaska Fairbanks, told The Independent that the explosions of plants and shrubbery, over what is typically a frozen tundra landscape, is linked to sea ice decline as the planet heats up.
“The tundra is very closely linked to the ocean, because it’s this narrow strip of land that’s very close to the Arctic Ocean,” she said of the region. “As the sea ice is going to decline, the tundra’s going to be impacted ... the ice is a really important factor.
“If the sea ice stays there into May, June, it keeps things cooler. As soon as that ice melts away, it warms things up. It basically moves away from the coasts as it’s gotten warmer, certainly over the 15 years I’ve been staring at it.”
Dr Bhatt, who is also associate director of the Cooperative Institute for Climate, Ocean and Ecosystem Studies, was co-author of a recent article published in the Earth Interactions publicationabout greening versus browning in Alaska’s Yukon-Kuskokwim Delta.
“The greening we’re seeing in that region is due to shrub encroachment,” she told The Independent.
The USGS satellite imagery measures the photosynthetic activity of certain plants. Increased activity indicates warmer temperatures. But while these plants and shrubbery thrive, it leads to complete disruption of the ecosystem.
“Losing sea ice is a painful, scary occurrence, because so much of these plants have adapted to that environment – so many plants will go extinct,” she said.
“And what’s happened is, shrubs are moving farther north, and the whole ecosystem is changing ... marine mammals tied to see ice, many of them will have to go extinct or adapt. Sea ice plays a very important role in the Arctic.”
The upending of a fragile ecosystem means everything gets thrown into chaos.
“There are indigenous groups in the Arctic that are reindeer herders,” Dr Bhatt told The Independent. “As the shrubs have gotten bigger, it’s much harder for the reindeer to forage ... They’re losing their reindeer. Some of them get left behind because they’re in the bushes.”
And the impact of a greening Arctic is much more far-reaching, she said, so everyone should be concerned.
“The greatest impact of the sea ice decline and the warming of the land is the thawing of the permafrost – so that is going to impact the vegetation, but that has many other cascading impacts,” she told The Independent.
“There’s a lot of carbon stored in the Arctic, and that can release carbon in the form of methane – and that’s a global issue.”
According to the US Environmental Protection Agency, methane accounts for about 20 per cent of global emissions and is “25 times as potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled”.
In other words increased methane emissions mean raises temperatures across the globe.
The USGS satellite imagery was captured at a time when regions from Siberia to California are battling major wildfires. It’s all tied together, Dr Bhatt said.
There is “consistently increasing evidence that these changes in the sea ice are affecting weather patterns to make things more variable in the continental US and the mid-latitudes,” she said. “The other thing is, it’s warm in the summer, you can have wildfires [and] we know wildfire smoke makes it very far distances.”
Smoke has made it to Alaska from a Siberian fire and from Oregon blazes to New York, she pointed out, indicating that ecosystem changes occurring in the Arctic are having impacts globally.
“You do not have to personally experience something to understand it’s a problem for society,” she said. However increased awareness on the realities of the climate crisis can still make a huge difference to combat it.
“People are just depressed, and I don’t want them to become hopeless – because then they won’t do anything,” she told The Independent. “They’ll stagnate.”
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