The arctic is greening. So says NASA. Its probably all that extra CO2.
Scientists from America’s space agency have found that nearly a third of the land cover in Canada and Alaska has greened in recent decades as a result of climate change.
As the far north warms as a result of climate changes, plants are moving north as well, “greening” the far north.
It also shows that the boreal forest is “browning” as a result of hotter and drier weather.
Greening is unmistakeable
NASA analyzed some 87,000 images captured by the Landsat satellite showing a trend towards much more plant life across the north. Their findings were reported in the science publication Journal of Remote Sensing under the title- The vegetation greenness trend in Canada and US Alaska from 1984–2012 Landsat data.
The data shows that about a third of the previously mostly barren tundra had become covered with plants. Areas that were previously grassland showed small shrubs had moved in, and in turn larger shrubs then took over even as the grasslands and other small plants moved further north.
The article also says:
a warming Arctic could release massive amounts of carbon stored in the Arctic soil and permafrost
Hey! Doesn’t more vegetation suck CO2 out of the air and store it in the ground?
sunshine hours 
Yes, increased vegetation does take some CO2 out of the air, and that is good.
In northern climates, increased vegetation also darkens the surface (since there is less snowcover), which decreases the amount of sunlight reflected back into space, which is not so good. Less reflected sunlight means rising surface and atmospheric temperatures, leading to more snowmelt, leading to darker surface, in a classic positive feedback loop. The overall result is more global warming.
Plant metabolism also produces heat (just as does the metabolism of any living thing), further feeding the feedback loop.
The overall effects of “greening” on the planetary climate depend in part on where the greening takes place. More vegetation close to the poles cannot directly replace the immense deforestation in temperate zones or near the equator, where the surface is darker to begin with (due to less snow cover and the vegetation that used to be there).
In the same way, the minor increase in seasonal Antarctic sea ice cannot directly replace the enormous loss of northern sea ice, even if the quantity of gain in the south matched the quantity of gain in the north (which it doesn’t; overall sea ice is shrinking, in both extent and volume). For one thing, Antarctic sea ice is seasonal; we are losing (what used to be) permanent sea ice in the north. For another, loss of sea ice in the north disrupts ocean currents and prevailing winds in the north. Gaining ice in the south cannot reduce the ocean and wind disruptions that happen at the opposite pole.
The place where a change happens inevitably has unique impacts which cannot be eliminated by changes elsewhere.
“increased vegetation also darkens the surface (since there is less snowcover”
Umm. I’m pretty sure that when it snows it lightens the surface.
And I’m sure when it is below zero in the arctic there is little melting.
And I’m sure the arctic melted in the 20s and 30s and then got icier.
“Umm. I’m pretty sure that when it snows it lightens the surface.”
Exactly what I said. Increased vegetation is darker than snowcover without vegetation.
“And I’m sure when it is below zero in the arctic there is little melting.”
And yet, there’s been record melting in the Arctic. Look at your graphs.
“And I’m sure the arctic melted in the 20s and 30s and then got icier.”
The Arctic (which of course includes both sea ice and permafrost) didn’t “melt” in the 20s and 30s, contrary to some of the current memes that reference some short-term small-area news reports of that era. The Arctic in the 20s and 30s was far “icier” than it is today.
Ice cores taken at various sites throughout the Arctic show that multi-millennial ice has been there for a very long time, most of it more than 50,000 years old.
The shrubs are not colonizing barren land. They are colonizing grassy areas.
The DMI graphs show pretty average temperatures in the Arctic.
And the arctic did melt in the 20s/30s.
And the warmest period in the arctic was around 8200 years ago.
http://www.sciencedirect.com/science/article/pii/S0921818115000417