At the top of the world the Arctic Ocean is usually covered by thick, vast, white pack ice, gently fluctuating in shape and size with the changing of the seasons. This sea ice regulates the Earth’s temperature and has been a permanent fixture in our understanding of how the world’s climate works. This year, that pack ice has retreated further and faster than anyone expected. The previous record of its retreat, set in 2007, was officially broken on 27 August when satellite images from the National Snow and Ice Data Centre (NSIDC) showed a reduction of nearly 50% compared to just 40 years ago.
Experts say the extent of the ice retreat is likely to be even larger next summer because this winter’s freeze is starting from such an enormous ice deficit. Peter Wadhams from Cambridge University is predicting that Arctic summer sea ice may collapse as soon as 2016. Researcher Wieslaw Maslowski of the Naval Postgraduate School in Monterey, CA projects a blue Arctic Ocean in summers by 2013.
The Cambridge University Sea ice researcher Nick Toberg, who has analysed underwater ice thickness data said:
“This is staggering. It’s disturbing, scary that we have physically changed the face of the planet. We have about 4m sq km of sea ice. If that goes in the summer months that’s about the same as adding 20 years of CO2 at current [human-caused] rates into the atmosphere. That’s how vital the arctic sea ice is.
Four decades of data have made the declining sea ice trend clear and experts are having trouble finding any records from Russia, Alaska or elsewhere pointing to such a widespread Arctic ice retreat in recent times. Many scientists say the last substantial warming in the region, peaking in the 1930s, mainly affected areas near Greenland and Scandinavia and was limited in scale. A 2011 study published in Nature journal, used proxies such as ice cores and lake sediments to reconstruct sea ice extent in the Arctic over the last 1,450 years with results suggesting the duration and magnitude of the current decline in sea ice as unprecedented.
But why is this important? Most of us have never even seen Arctic ice. Many who are quick to deny our role in a changing climate are even faster to seize opportunities created by its impacts. Governments and energy companies point to the new opportunities for trade via the ice free northern shipping route. A historic first drilling operation by Shell in Alaska demonstrated the oil and gas companies eagerness to move North. These new opportunities bring new threats to the already changing envionment, and risk exacerbating the ice melt.
The Arctic polar ice cap is important to regulating our atmosphere and oceans. The snow and ice usually form a white protective, cooling layer over the Arctic. When that covering melts, the darker ocean absorbs more sunlight and gets hotter, increasing the amount of heat in the climate system. NASA put out a video explaining the far reaching effects of the melting ice.
The Arctic is a highly sensitive region, and it is being profoundly affected by the changing climate. Most scientists view what’s happening now as a preview of things to come. The Arctic has long been considered the front line of coming climate change and the retreating extent represents this new kind of climate.
Worth mentioning is the state of Antartica. Many climate change nay-sayers are pointing to the record amount of ice recorded in Antarctica on September 12th 2012. In a very simplified sense the Arctic and Antarctic are reacting differently to climate change partly because of geographical differences. Antarctica is a continent surrounded by water, while the Arctic is an ocean surrounded by land. Wind and ocean currents around Antarctica isolate the continent from global weather patterns, keeping it cold. In contrast, the Arctic Ocean is intimately linked with the climate systems around it, making it more sensitive to changes in climate.
Both extremes represent a changing global climate and it is important to remember that extreme changes are forecasted as one of our emerging climate characteristics.