photo taken by renown wildlife photographer and conservationalist Paul Nicklen
The newest figures regarding the ongoing Arctic meltdown are out and all but reassuring. This comes hardly as a surprise to those who have been observing the worrying developments in the area over the past years or decades. According to a special report in the Economist, the Arctic has warmed up twice as much as the global average since the 1950's. The rapid decrease of summer sea ice in the Arctic Ocean, found at a record low in 2007, and the melting of the Greenland ice sheet that is predicted to soon pass a point of no return have developed into a solid, downward spiral trend, and whereas previous predictions suggested that the northern polar cap could be ice-free in summer by 2030 (eg Mark Serreze, NSIDC), more recent calculations now deem possible an even earlier date for the event.
The Arctic is warming up faster than any other region in the world, for a number of reasons: Firstly, it is particularly exposed to the snowballing effects of global warming due to its geographic locality: heat always shifts from the tropics towards the poles, transported by the atmosphere and ocean currents ( see also "thermohaline circulation"). Whereas, however, the much colder Antarctic (average annual temperature: -57 degrees Celsius) is completely surrounded by the Southern Ocean and mainly impacted by its dominant current, the ACC (Arctic Circumpolar Current) that has kept warmer ocean currents in that area largely at bay so far, the Arctic is surrounded by land bodies that prevent the Arctic Ocean from circulating freely; hence, increasing atmospheric and ocean temperatures are set to hit the Arctic more profoundly than, by comparison, Antarctica (It should be mentioned, however, that specifically West Antarctica, too, has experienced unexpected ice loss lately due to warming ocean currents, a result of changing wind and weather patterns, induced by global warming). Secondly, the warming of the Arctic, as much as any other locale in the world, is primarily caused by increasing amounts of heat-trapping gases released into the atmosphere mainly by burning fossil fuels. The predicted two degrees Celsius rise in global temperature spells an average warming of three to six degrees Celsius in the Arctic (and severely changing climate conditions in Antarctica as well); since the polar regions act as a sort of planetary air conditioning system, such a powerful climatological shift will have unpredictable but certainly far-reaching consequences not only for, say, polar bears and emperor penguins, species many might feel indifferent about, but rather for every single one of us, whether we live in Dhaka, Murmansk, Paris or New York.
Thirdly, a phenomenon called the albedo effect makes for much of the regional surface warming in the Arctic that has been recorded so far: the polar snow-white land and ocean icescapes are highly reflective, but as the melting ice gives way to dark water or land, an increasing amount of solar radiation is absorbed; temperatures rise and further speed up the melting process. Soot, carried by winds from Europe and Asia to the North, clads the polar ice or snow, thus changing its albedo.
And then there is yet another strong positive feedback loop influencing local temperatures in the Arctic Circle: the thawing of permafrost soils that are expected to release massive amounts of heat-trapping gases to the lower atmosphere in the years to come, primarily the extremely potent greenhouse-gas methane (methane is twenty to twenty-five times as effective in trapping heat as is carbon dioxide): As unexpected amounts of hitherto ice-packed organic material start to surface and decay, huge quantities of carbon dioxide and methane will enter the earth's atmosphere (Supposedly, the world's permafrost soils hold twice as much carbon as the entire atmosphere).
All these trends taken together spell rather bad news for climatic and environmental developments in the future; it can't be stressed often enough that the impact will be a worldwide one: changing ocean currents and weather patterns, a slowing of the so-called ocean conveyor belt, part of the planetary heat-shifting system, that would very likely bring about much harsher winters in most of Europe, drying tropics, the disappearance of food fish in ocean waters around the globe due to large-scale nutrient depletion in Pacific and Atlantic waters, rising sea levels and, as a result, the disappearance of islands, flooding of low-lying land and numerous megacities around the world, displacement of hundreds of millions, etc are only some of the possible consequences that could ensue the partial melting of the polar caps.
The Arctic ecosystems, for that matter, are already undergoing dramatic changes, in particular the micro and macro worlds of the Arctic Ocean, harbor of a plethora of well-adapted and highly specialized species such as the polar bear (ursus maritimus), sea leopard (hydrurga leptonyx), the walrus (odobenus rosmarus), the ringed seal (pusa hispida), and the notothenioidei or arctic icefish whose bodies contain specialized glycoproteins that keep their blood from freezing at icy water temperatures of -2 degrees Celsius.
At first sight an environment seemingly hostile to life, the sea ice, as E.O. Wilson has nicely pictured it in his most readable book The Future of Life, is really the gardens and soil of the arctic landscapes. Microscopic ice algae thrive in intercrystal channels; feeding on nutrients that rise from the ocean floor year-round they are the main dish of the tiny crustacean c.glacialis, a copepod rich in lipoids, abundant on the ice's edge and the very base of many arctic food chains. krill and various types of fish graze on the underside of the large ice chunks upside down, eating away on the copepods and other sympagic organisms; small seals and minke whales feed on krill, and polar bears and sea leopards feed on small seals. The described decrease in sea ice and the accompanying shrinkage of sympagic food sources thus puts many participants along the chain but particularly the large top of the food chain arctic predator mammals at risk of extinction. Naturally, the melting North will open up new frontiers for countless lifeforms previously restricted to environments further down south: coniferous forests will push into formerly inhospitable Arctic regions, parts of Greenland ice will give way to tundra growth. The one animal that will definitely thrive in an environment of thawing permafrost and a generally warming Arctic is, as always, homo sapiens, who will eventually be able to use the emerging ice-free land for growing crops.
Still, the definite outcome of such large-scale ecologic alterations is impossible to predict. Climate changes of a comparable or even greater order have, of course, ocured before in Earth history, but probably never as rapidly as has been suggested for the centuries to come. Many species will encounter great difficulties in adjusting to the new environmental conditions or fail entirely.
The recent discovery of hitherto unknown massive phytoplankton blooms beneath huge shelves of sea ice by the NASA icescape mission in the Chukchi sea, north of Alaska, has thrown up a row of questions such as to which extent species that habitually accord their mating and breeding cycles precisely to the annual algal blooming, will be affected by the event: the copepods for instance, that hibernate in the deep water and rise to feed on algae in spring might either benefit from prolonged blooms or, if they arrive too late to the party, lose out and die in the cold.
The finding of the 100km phytoplankton stretch also indicates that multiyear ice usually so thick no ray of sun light will pass through is melting at alarming rates. Algal growth has been found to be even more abundant under the ice than in the open ocean, much to the surprise of the scientific community. Growth rates under the ice are exceeding all calculations for phytoplanctonic growth in the Arctic Ocean previously made, knows the missions leader Kevin Arrigo, Professor at the Department of Environmental Earth System Science (EESS), Stanford University, California. Cell division that would normally take three days suddenly happen once or twice a day.
Whatever the implications, there is one fact about the icescape mission's discovery that can hardly be denied: it provides
further and disturbing evidence for the rapid change of Arctic ecosystems currently under way; we can read the finding as yet another harbinger of a great wave of global warming induced changes to our biosphere that is going to hit much sooner than we would have guessed a decade or two ago.