Arctic Circle

<<

University of Exeter, UK Svalbard

Future projections of climate change imply our planet is moving into a ‘super-interglacial’, a sustained period warmer than present. One of the most sensitive regions of our planet to this change is the Arctic, where natural processes are exaggerating the increasing temperatures felt around the globe. The region is already suffering some of the earliest effects of human-induced climate change, many of which have been spectacular. In September 2007, the fabled 5000 km long waterway known as the Northwest Passage opened up as a navigable route without the need for ships armed with ice breakers.

For centuries, finding a path through the region had been the stuff of dreams. Celebrated endeavours have been made over centuries to find an opening between the north Atlantic and Pacific but most revolved around ships smashing their way through the ice, or in the case of some Victorian expeditions, resorting to cannibalism when all hope was lost. More success has been had along Russia’s northern shore – the so-called Northeast Passage – but the going was still tough. It’s been 130 years since the first successful navigation of the Northeast Passage when the Swedish steam barque Vega managed to make it’s way through this route, reaching Japan in September 1879 after a hard winter locked for ten months in the sea ice off the Siberian coast. Since the summer sea-ice low of 2007, ice coverage has fallen even further, opening up the Northeast Passage completely and allowing the North Pole to be circumnavigated in 2008 for the first time in recorded history. It’s not taken long for the commercial opportunities to be realised. In 2009, the first trading ships passed through the Northeast Passage, a worrying indication of what might come to be the norm.

During the 1970s there used to be over 50 per cent sea ice cover in the Arctic, but by 2008 this had crashed to less than 30 percent.  As the cover has dropped, so too has the thickness of ice. At the height of the Cold War, UK and US military submarine missions in the Arctic would routinely direct their sonar towards the surface to work out whether they could punch through the surface in an emergency and launch a missile at Moscow. Much of the submarine data has now been released, providing a treasure trove of valuable data. Put together, the data show a disturbing trend: the ice is getting thinner and on average younger. In the 1980s over 20 per cent of the Arctic sea ice was at least six years old but by 2008 this had declined to just 6 per cent. The thinner the ice, the less likely it will survive through the summer and the harder it is for the subsequent winter to build ice levels back up at the surface. This all has big climatic implications beyond the Arctic. Because the sea ice is so reflective, around 90 per cent of the heat received from the sun at these latitudes goes back out to space, making this region a massive natural refrigerator that help keeps our planet cool. The problem is as the ice cover goes, the summer heat is absorbed by the ocean and rereleased back into the atmosphere later in the year when the next phase of sea ice is supposed to be forming; autumn temperatures are now a staggering 5˚C above normal for the region.  As the oceans warm the overlying air, these temperatures start to reach far inland, melting areas of permanently frozen ground in the region. Year on year, these feedbacks become stronger, accelerating the loss of ice cover and increasing the warming over the region relative to the rest of the planet. As a result, recent Arctic warming is almost twice that the global average. The region is the quintessential ‘canary in the goldmine’ as the planet warms. The island archipelago of Svalbard is an excellent location to explore what is happening today and in the past to get a better handle on the future.


University of ExeterJISCGeography Earth and Environmental SciencesC-Change

© University of Exeter 2010 | Creative Commons License