The rapidly warming Arctic region is the perfect proving ground to show how climate change impacts have a synergy that is amplified by human activity, primarily greenhouse gas emissions.
A new study finds that the rate of Arctic sea ice loss is influenced by warming far south in the Pacific. It links the effects of the Pacific Decadal Oscillation (PDO) to events across the Arctic Ocean. What troubles scientists is that the PDO is currently in its negative phase which should, but hasn't, brought cooler waters to the eastern Pacific. The positive phase will see warmer waters along the west coast of North America which will increase the impact on sea ice loss.
Another study explores a geological feature found across the permafrost, ice wedges. These ice spikes can span up to 30 metres at the surface. As they melt, the surrounding permafrost is no longer supported an collapses. In some places the surface subsidence has been recorded at 10 cms. or 4 inches per year. Much of the territory in the far north is already low lying and hence the subsidence makes these regions vulnerable to inundation from the sea.
Finally, from The Washington Post, "Dominoes Fall: Vanishing Arctic ice shifts jet stream, which melts Greenland glaciers." The warmer Arctic atmosphere has changed the Polar Jet Stream and given rise to blocking events that take the form of stationary waves (Rossby waves) that can plunge far south and simply stay there. This often takes the form of the dreaded "polar vortex" events that hit eastern North America. These blocking events were instrumental in the last severe flooding event in Calgary where a massive rainstorm was left parked over the area for several days.
Now it turns out that this newly energized Polar Jet is accelerating the melting of the Greenland ice sheet.
A recent set of scientific papers have proposed a critical connection between sharp declines in Arctic sea ice and changes in the atmosphere, which they say are not only affecting ice melt in Greenland, but also weather patterns all over the North Atlantic.
The new studies center on an atmospheric phenomenon known as “blocking” — this is when high pressure systems remain stationary in one place for long periods of time (days or even weeks), causing weather conditions to stay relatively stable for as long as the block remains in place. They can occur when there’s a change or disturbance in the jet stream, causing the flow of air in the atmosphere to form a kind of eddy, said Jennifer Francis, a research professor and climate expert at Rutgers University.
A paper set to be published Monday in the International Journal of Climatology reveals an uptick in the frequency of these blocking events over Greenland since the 1980s.
Last week scientists reported that the ice melt season had arrived in Greenland a month ahead of normal. The season kicked off with one day that took researchers by surprise on which the ice sheet lost a cubic kilometre of water, a gigatonne.
What is emerging is clear proof that, when it comes to climate change impacts, everything has "knock on" effects. It's all inter-related, causally linked. It's something out of the mind of Rube Goldberg.