Flip-flops in Greenland?
We’ve been following a warming spell in Greenland for a while, alerting about its strengthening last week and also touching upon it earlier this week in conjunction with the freeze in northern Europe. It has only gotten worse, and this has significant repercussions for the entire globe.
It’s not even the Arctic melt season and temperatures have already soared more than 50F above normal in some parts of Greenland. The capital, Nuuk, saw temperatures peak at 59.4F (15.2C) last Sunday – far warmer than the city’s average high of 23F (-5C) for this time of year, according to the Danish Meteorological Institute. Temperatures in the northern part of the country, however, are where the even scarier anomalies have appeared – there it has been between 30-50F (17-28C) above what is expected for this time of year.
Why is this occurring?
This warmth is actually related to the same reason that the UK is currently in snow warnings! What is occurring is a phenomenon commonly known as a ‘Greenland block’, an area of high pressure that hangs over Greenland and causes the air below it to warm. This block is the result of an earlier disruption to the polar vortex, known as a sudden stratospheric warming event (SSW). This same SSW that is leading to flip-flop weather in Greenland is causing parka weather in the UK.
So what does this mean for the summer melt season? For the climate crisis?
Not only are shoulder-season warming events indicative of the worsening climate crisis, but such pre-season warming can “precondition for earlier melts [because] if the temperature of the existing snow is higher than it would otherwise be, there is less heat required to bring it to the melting point” according to Arctic Basecamp Scientist and Greenland specialist, Jason Box. Although not on scale with a mid-season melt, it is the largest melt episode for this time of year in more than 20 years.
A strong winter snowpack is one of the best precautions against summer melt on the island that is currently the largest contributor to global sea level rise. As its snow and ice melt, its ability to reflect incoming solar radiation is reduced, thereby more heat is absorbed and ultimately trapped in the Earth’s atmosphere. Even if all emissions were to cease immediately, Greenland is still expected to lose 3% of its mass, leading to a global average of 27cm (10”) of sea level rise.