A recent study says that the Arctic sea ice melt will happen as early as this year. This doesn’t just spell doom for island nations and coastal regions, but for the entire human and animal population too as there will be changes in the climate pattern, experts tell SHAlINI SAKSENA
All those people who had not been paying attention to the repercussions of global warming, here is a chilling fact — the Arctic sea ice could disappear by the end of this summer or by next. Professor Peter Wadhams from Cambridge University has predicted that the Arctic sea ice may collapse entirely. The reason is global warming due to carbon dioxide and other greenhouse gases being released into the atmosphere. For various reasons, warming is faster in the Arctic than at lower latitudes.
“Air temperatures have become much higher in the Arctic so the ice does not grow so thick in the winter and starts to melt earlier and faster in the summer. The result can be that all the ice which grows in the winter melts in the summer. This never used to happen in the past, when the ice grew thicker each year. Contributing factors are warmer water entering the Arctic from the Atlantic and a changed wind system which moves ice out of the Arctic quickly instead of allowing it to circulate inside for many years,” Prof Wadhams explains.
There are three big threats due to this melt. First, the reduced area of sea ice means that the global albedo (amount of solar energy reflected back into space) is reduced and the planet warms up more rapidly.
Second, the open water in summer means that warmer winds blow over the nearby Greenland ice sheet, causing it to melt more rapidly leading to increase in sea levels.
Third, the open water in summer warms up because of solar radiation, causes seabed permafrost to thaw in coastal seas and allows large amounts of methane from sediments to be released into the atmosphere. Methane is a powerful greenhouse gas that speeds up global warming.
But, believe it or not, while the Arctic is melting at a pace that environmentalists would like to stop, the Antarctica’s sea ice is growing. Prof Wadhams says that this phenomenon is difficult to understand but could be attributed to the grown intensity of westerly winds that blow around the Antarctic.
“A westerly wind causes the ice to move eastward but with a northerly component to its motion. With faster winds the northerly component increases, so the ice flow is moved to lower latitude before it melts. So although the Antarctica is warming up, the ice can now extend to lower latitude,” Wadham opines.
But according to India-based climatologist Prof Murari lal, the reason for Antarctic not melting is because the ice is over land unlike in the Arctic where the ice is over water.
“Almost 90 per cent of the heat is still absorbed by water bodies — oceans. This means that the ice at North Pole is not only melting from the heat above but also below, expediting the melt faster. One can even see the impact of the warming of the oceans even at a depth of 1,000 feet and how it is affecting the marine life, the corals, etc,” lal says.
So, while the Antarctic is safe for now, it is the Arctic which is a cause of worry. “The ice won’t disappear in the winter, at least not for a long time yet. But yes, it will disappear in the summer (September) and this may happen as early as this year, though it is more likely to take another two to five years for this to happen,” says Wadhams who has based his prediction on projected data from the National Snow and Ice Data Centre in the US.
This means that as the ice retreats, there is less reflection of sunrays and the heat is absorbed by the ocean which further melts the ice. The loss of this reflective sea ice has led to the rise in Arctic temperature threefold.
Also, as the land ice melts, it adds freshwater to the oceans causing sea levels to rise. This is definitely a cause of worry for all island nations and those with a long coastline including India and Bangladesh.
Another impact is that the freshwater runoff into the ocean may disrupt a major circulation system known as the Atlantic Meridional Overturning Circulation (AMOC). This circulation carries warm surface water northward, giving Europe a mild climate. It is predicted that the AMOC can slow down by an average of 25 per cent by 2100. This means that the freshwater from melting ice could become a major factor in climate change and affect the Indian monsoon.
And howIJ “Warm water currents move from the tropical region to the poles where they become cold and increase the salinity of the oceans. This causes the water to sink and release heat. This is how western Europe has a warm climate. But melting of the ice disrupts this cycle as more and more fresh water is released in to the oceans at the poles. This decreases the salinity of oceans, preventing warm water from sinking and releasing heat. This leads to cold waves across Europe and the water then travels southward, causing temperature difference between land and oceans in the tropical regions. The result — changes in monsoon patterns,” Dr M Ravichandran, director of the Goa-based National Centre for Antarctica and Ocean Research, says.
As for the timeline related to the Arctic melt, “it may or may not happen within the said period. But it can’t be denied that the melting is a cause of worry and one needs to conduct more studies and research. It is not possible to say with conviction that the Arctic will be free of ice, if not this year, then next. For example, there is no way that one can predict that the monsoon next year will be good or bad. In the Indian context, for now, what we need to be alarmed about is the thermosteric sea level rise due to the thermal expansion of the Indian Ocean rather than the melting of the ice at the North Pole,” Ravichandran opines.
This doesn’t mean that the country is in the clear. He tells you that the melt is due to heavy rains, especially in the North-west regions. When it rains, the Earth’s heat is released into the atmosphere which gets transported to the Poles, which then settles down, causing the ice to melt. So while India may not directly be affected, we can’t shy away from the fact that due to globalisation, any impact that the melt may have on the countries bordering the Pole, there is always an indirect impact like the change in the pattern of the ocean currents. While there is a physical link that heavy rains lead to melting of the ice caps, a link that this melt will affect the Indian climate is yet to be ascertained. Studies in this regard are been conducted and the pattern is being studied.
“One has to study the oceanic current cycle and how often there is a change in the cycle. Sometimes it is 200 years, sometimes 400. One has to understand that when we talk about change in climate, it is always long-term. But yes, the ocean currents do affect the climate of a region and can affect India too,” Dr Ravichandran says.
Considering that large parts of the country are facing drought, any change in the monsoon affects not just the people but also agriculture as well. This means that the melting of the Arctic ice is definitely a bane for the country and a serious threat to the environment and the animals like the polar bear. There have been reports that the weight of these bears has fallen drastically. A study conducted by the Canadian researchers published in the journal Arctic Science said that the drop in weight was strongly correlated with melting sea ice. Using data from 900 bear captures carried out at varying points between 1984 and 2009, researchers found that the average weight of males had dropped by 45kg and females by 31kg.
Since 1980, the ice season in Hudson Bay has fallen at a rate of about one day a year, forcing polar bears to spent more time on dry land rather than hunting seals — their main source of food — on sea ice. Polar bears now get some 30 fewer days each year on ice than previous generations. While the loss of weight has not led to a decline in the population of polar bears, it could change as a warming Arctic continues to melt away sea ice.
“Polar bears are having trouble finding ice to hunt seals in spring. But plankton and fish are more prolific because more light reaches the water,” Prof Wadhams says.
Though, economically the opening of the Arctic will prove to be a boon for the shipping companies who are, at present, hundreds of thousands of dollars on fuel to transport good and have to take a circuitous route since the Arctic is under ice. If the Arctic opens up, it will not only reduce the cost of transportation but also reduce travelling time to half. Something that countries like Iceland, Greenland, Finland and Russia have been waiting for. Besides shipping, the other benefits include increased agricultural productivity and expanded opportunities for mineral extraction which will make a big difference to them in a world that is changing rapidly.
“For oil exploration and transport, the Russians would like there to be less ice. But for the planet, an ice free Arctic is very bad,” Prof Wadhams says.
lisa Speer who directs the international oceans program at the Natural Resources Defense Council, an environmental organisation with its headquarters in New York, also tells you that global warming is, without question, the primary cause of the dramatic decline of Arctic sea ice. “We have entered a destructive feedback loop whereby melting white ice exposes dark ocean, which absorbs heat from the sun more readily than reflective ice. The absorbed heat melts more ice, and so on. Black carbon air pollution from other parts of the globe contributes to the problem — the black emissions settle on the ice, absorbs heat, and contributes to the melt,” Speer says.
While it is not clear how the sea ice melt will affect the climate due to losing of the Earth’s polar air conditioner, one thing is certain, it is not likely to be good.
This is because in addition to climate effects, the loss of Arctic sea ice poses a fundamental threat to ice-dependent species like polar bears, ice-seals and fish, along with the coastal communities that depend on these animals for basic subsistence and culture. “How it will affect the climate of a particular place will be difficult to say,” Speer tells you.
But Prof lal says that since some places have already seen a rise in water levels to up to a metre or two, the impact of ice cap melts is already being felt in regions like Florida where a study is already underway on how this rise will impact the ports and what needs to be done.
“Since the prediction is that the ice cap melt will lead to a rise in water levels by up to seven metres, one can only imagine what it will do to not just island nations but also India. How this rising levels will affect the climate of the various regions and, in turn India, is unclear. One thing, however, is certain — that the Arctic melt is a bane for the planet,” lal opines.
It is not as if there is no solution. There is still time to take corrective measures since the Arctic’s melt will only happen in September in certain areas. First, is geoengineeering. It has been shown that by injecting very small water particles into the bottoms of clouds, the clouds can be made whiter, increasing the reflection of radiation. With a lot of ships with tall masts injecting water into clouds, this could stop global warming and allow the ice to grow back. The technique is called marine cloud brightening.
“The second, is on a local Arctic scale, the emission of methane from the seabed could be slowed or stopped by a technique like fracking, wherein holes are drilled under the sediments and the gas run to a cavity then pumped out,” Wadhams explains.