The Arctic is the Earth’s northern polar region, which includes the Arctic Ocean and its seas, northern parts of the Pacific and Atlantic Oceans, the Canadian Arctic archipelago, Greenland, Svalbard Island, Franz-Josef Land, Novaya Zemlya, Severnaya Zemlya, the New Siberian Islands and Wrangel Island, as well as the northern coasts of Eurasia and North America.
There are no hard and fast boundaries of the Arctic region. The most common definition of its southern boundary is the Arctic Circle at northern latitude of 66 degrees and 33 minutes. In this case, the total area of the Arctic equals to 21 million km2 (Fig. 2.8.1).
A second definition of the Arctic region is the July isotherm – an imaginary line where temperatures in the warmest month of the year are not greater than 10 °C. The tree line roughly correlates to the July isotherm and it is the third definition of the Arctic. Tree line marks the transition from the forests zone to the shrubs and grasses of the tundra. The Russia, the United States (Alaska), Canada, Norway, Sweden, Finland, Iceland and Denmark (Greenland) all have Arctic territories.
The Arctic is getting warmer more quickly than the rest of the world
Climate change in the Arctic is much more pronounced than on average in the world. Temperatures along Arctic coast have risen already by 2-3 °C in recent decades. But the most noticeable effect of climate change on the Arctic has been an increase in fluctuations of climate and weather. In temperate climate sudden changes of temperature are usually not greater than 10 °C: it may be quite warm today, but tomorrow the temperature falls by 10 °C, and then it rises again by 10 °C a week later. But in the Arctic the temperature can experience sudden changes of as much as 20 °C, and it often happens that summer temperatures in one
Arctic region are 5 °C warmer than they were in the mid-20th century, while in a neighbouring region they are 5 °C cooler.
It might seem that warmth in the Arctic is a good thing, but that is not always true! Which is better: a temperature of -35 °C with clear, windless weather or -20 °C with a blizzard? Of course, it’s better to be colder, but without the blizzard, particularly since the Arctic is used to such temperatures. The issue is not temperature as such: whatever happens, temperatures in the Arctic will never be high enough for people and animals there to get overheated.
The lives of people and ecosystems in the Arctic are affected by various climate parameters: the power of the wind (blizzards and storms), reduction of the extent of sea and river ice, severe coastal erosion and the melting of permafrost. Changes to these parameters are not just a consequence of rising temperatures – the parameters themselves are active forces that are helping to drive temperatures upwards. Scientists call such inverse effects ‘feedbacks’. There are at least two of them.
1. Higher air temperatures cause ice fields to melt and break up, leaving large expanses of open water between ice floes. The dark surface of the water, unlike ice, does not reflect but absorbs solar radiation, so the water grows warmer, more ice melts and the process is accelerated.
2. More open water means more evaporation of moisture and more clouds. Remember, nights are relatively warm when the sky is cloudy, because clouds trap heat, and it is much colder
on a clear night. Similarly in the Arctic, when there is a a lot of open water and clouds, the temperature is higher, especially at night, which also speeds up the melting of ice.
The disappearing ice of the Arctic
Scientists have been monitoring ice in the Arctic since 1979 by means of satellites. Satellite data show that the amount of ice in the Arctic has declined dramatically (Fig. 2.8.2). Over the past 35 years, the extent of ice cover in the Arctic Ocean and its seas has decreased by 15–20%.
The area of ice is usually measured by its minimum extent for the year, normally at the end of September. The shrinkage in September 2012 set an absolute record: the area of sea ice shrank to 3.41 million km2 (Fig. 2.8.2 and 2.8.3).
Of course, ice still covers the whole of the Arctic in winter. Even gigantic warming of 15–20 °C would not lift winter temperatures in the polar regions above zero. But the ice thickness would be much reduced. This effect is very clearly visible even now.
Scientists note that reduction in the extent and thickness of sea ice will offer new opportunities for greater use of the northern sea route for transporting goods between Europe and Asia and vice versa. The route via the seas of the Arctic Ocean is much shorter than the traditional route through the Suez Canal and can significantly reduce the cost of shipping.
Ships have the best chance of traversing the northern sea route in September, when the area of ice is at its lowest extent. But, as can be seen in Fig. 2.8.2, even when ice cover is at its lowest ever, there is no guarantee that all of the straits will be open. This is particularly true for the Vilkitsky Strait between Taimyr and Severnaya Zemlya, which represents a bottleneck for the entire Northern Sea Route. This Strait remained ice-bound even in 2007. On the other hand, there are occasions when the overall ice cover is much greater, but straits are passable. In sum,it is too early to speak confidently of ice-free navigation along the Arctic coast of Russia at present. Climate models suggest that the Arctic will only become completely free of ice in the summer from about 2050.
It is important to remember that melting of ice in the Arctic leads to the formation of icebergs, which can be dangerous for ships, as well as for oil platforms positioned on the continental shelf in the open sea. In the future shipping and oil companies will need to ensure proactive protection from icebergs in order to avoid to avoid collisions and accidents.
Threats to the animals in the Arctic
The melting of ice in polar regions has major impact on marine animals, including the “king” of the Arctic – the polar bear. He does not need ice as such, but his main prey are seals, which are always found at the ice edge.
Due to global warming the ice edge now retreats northwards very quickly in the Arctic spring – so quickly that polar bears do not have time to react and are cut off from the seals by vast expanses of ice-free water (Fig. 2.8.4). A bear can swim for dozens of kilometres, but not for hundreds of kilometres, and the swimming ability of cubs is very limited. As a result a large number of animals are stranded on the coast. They grow hungry and may enter villages to seek food at garbage dumps, which can be very dangerous, both for the animals and for people. There are ways of addressing this problem. Firstly, people should have means of deterring bears, such as guns that fire rubber bullets. Secondly, villages should be kept clear of old food waste, which should be taken at least 1–2 km away from the village, so that the bears go there, and not to places where they are likely to meet people. Thirdly, a watch needs to be kept on the bears by men who are specially trained, armed and equipped to do so (with radios and satellite phones as part of their equipment). This would enable prevention both of bear attacks on humans and of poaching.
Although having to do without their favourite meal of seal, bears can find enough food to eat on the sea coast (dead birds, eggs and small animals). They can also hunt walruses, although a polar bear will not tackle an adult walrus: a weak, wounded animal or walrus calves are better prey. Bears will sometimes break into a walrus rookery, causing a panic in which the walruses press together and calves are crushed by the large males, leaving food for the bears. Such tactics are particularly successful if walruses have made their home not on a flat beach, but on a slope or on cliff ledges: as the large animals fall downwards they may crush younger animals beneath them.
Walruses are increasingly forced to choose such unsuitable places for their colonies, also due to the lack of ice. Walruses not only need ice floes, on which they can rest during migration without losing their strength. They also need shore ice. Previously, there were large quantities of thick, coastal ice, part of it lying on the beach as a crust. Now there is much less of it, and storms are rapidly eroding suitable sites for walrus colonies! The animals are therefore forced to choose other places, where they are threatened not only by bears, but also by people. There have been instances when thousands of walruses have
appeared in new places (Fig. 2.8.5), including locations near to aerodromes. The sound of an approaching aircraft caused a panic stampede, in which dozens of animals were killed. To prevent this happening again, people at the aerodrome made noise on purpose before the arrival of planes, so that the walruses would take to sea. But such solutions require careful monitoring of the movement of walrus populations, with the deployment of people and equipment.
The Barents and Kara seas are the habitat of the Atlantic walrus, which is listed in the Red Book. There are only a few rookeries of these animals, some of which are located in remote areas of Franz Josef Land, but others are in relatively accessible places, along transport routes and in locations where there are plans to build oil and gas platforms. It will be essential to carefully monitor and identify problems early on, in order to avoid the disappearance of walruses in this part of the Arctic.
The survival of harp seals in the White Sea presents another challenge. Unlike bears and walruses, seals cannot live on the coast, where they fall easy prey to wolves, dogs and other predators. For a long time the harp seal was hunted by the human population of the Arctic coast, and the white fluffy fur of young cubs was specially prized. Hunting is now prohibited. Many seals also perished due to the passage of ships through areas where they lived. Ships’ captains are now required to avoid places where seals congregate.
Seals have another problem caused by climate warming: the fur of seal pups is very warm, but not waterproof, so falling into water or even into puddles formed on the ice as it melts can be fatal for them: they freeze, fall ill and often die. In the future, if quantities of ice are much reduced it may be necessary to find a protected island where young pups can grow up in safety.
Reindeer are also being affected by climate change. Poor ice cover on rivers means that herders find it harder to guide the herds to the right places at the beginning of the winter. Reindeer can swim across a river, or walk across on sturdy ice. But they cannot cross a river with weak ice. The disappearance of ice on rivers earlier in the year and melting of the tundra create obstacles to reindeer migration and often leads to the death of many animals.
We cannot stop climate change easily and quickly, so it is vital to address such problems by removing other man-made barriers. For example, by making sure that gas pipelines do not interfere with the migration of reindeer. At present pipelines in the permafrost zones are built above the ground on special supports, and deer can neither crawl under the pipes or jump over them. Special overhead sections are needed so that the animals can pass under the pipes.
Melting of the permafrost
Melting of permafrost presents an even bigger challenge (Fig. 2.8.6.). People have lived in the Arctic permafrost zone for many thousands of years, but they were indigenous peoples (Chukchi, Nenets, Yakuts, Evenks, Aleut, Yupik and Inuit) who did not build houses, and their existence did no damage to the frozen ground in the Arctic permafrost zone. When Russians first came to the Arctic and found that the ground freezes to a depth of several metres and that only the top layer melts in the summer, they were much surprised. Leaders of the colonists wrote that the land was frozen, so that it was impossible to sow wheat. In the Russian city Yakutsk, a well was dug to find out how deep the frozen soil went: in 1686, it was dug to a depth of 30 m, but did not reach the bottom of the permafrost. Some 150 years later work on the well resumed and it was dug to a depth of 116 m, but the ground at that depth was still frozen
The nature of permafrost was only understood at the end of the 19th century, when it was found that permafrost went as deep as 1,500 m in some places, but the frozen layer, with temperature between -2 and -7 °C, usually had thickness of 100 m.
In places where there is no permafrost, the sub-soil temperature is always a few degrees above zero, so that water pipes can be safely laid and streams and small rivers be channeled through pipes and tunnels, as may be necessary in towns and cities. The top layer of soil thaws in the summer, but the frozen layers remain in place from a depth of 10 cm in the north to 1 m on the southern permafrost boundary.
Buidling on permafrost ground is very difficult due to problems with foundations. Frozen ground cannot be dug, but must be laboriously broken up or melted. It is possible to drill, saw, and even explode the permafrost, but that is expensive and requires special equipment. The permafrost contains large quantities of ice – sometimes whole layers of it (Fig. 2.8.7).
So, when the top of the permafrost melts in the summer, it forms a very weak ‘semi-liquid’ layer, which is incapable of supporting buildings, bridge supports or power lines. Such constructions have to rest on stilts, which go deep into frozen ground, reaching levels at which the ice never melts.
Further problems arise from the fact that the summer thaw is very uneven. The surface terrain is not flat, and the nature of the ground may alter just a few metres to the left or right. It might happen that more water accumulates in a certain place during the warm season and cannot escape underground due
to the permafrost. When the winter comes, the trapped water freezes into ice inclusions (lenses) and layers. Ice occupies more space than water, so the ground swells. Bumps and irregularities are formed, which can destroy buildings and roads (Figs. 2.8.8, 2.8.9).
The problems do not end there. As climate warming advances, a particularly warm year may cause thawing of the permafrost to a deeper level than usual, and the trapped water escapes. This creates empty spaces underground, the land subsides, and bridge supports, power lines or even a small building can collapse into the ground. This effect is called thermokarst. It is highly dangerous, and its widespread nature due to global warming could not be foreseen when buildings were designed and built in the Arctic in the past (Figs. 2.8.10, 2.8.11).
Leakage of water into the ground due to human action adds to the risk. Further weakening of the permafrost due to global warming could lead to major thermakarst problems associated with leakage from water and drainage pipes, which was less dangerous when the permafrost was well established. Rules that need to be followed include clearing of snow from roofs and the areas around a building before it melts, as water should not be allowed to penetrates beneath the building.
What is to be done? We cannot stop climate change quickly, and the amount of damage done is increasing rapidly. Large amounts will have to be spent on direct freezing of soils, and on the design of more expensive buildings, which can cope with the new conditions.
Maintenance of permafrost in the Arctic can be ensured by relatively simple devices. Sometimes underground ventilation ducts are sufficient: very cold air from the surface freezes the ground to such low temperatures that it does not have time to thaw in the summer. This method is particularly suitable for roads, which are on raised embankments. The soil of the embankment can be kept frozen by laying pipes with about 20 cm diameter, 50 cm apart , from one side of the embankment to the other.
Ground can also be frozen using devices called thermosiphons – vertical tubes, hermetically sealed at both ends, with their lower part in the ground, and their upper part rising 2–3 m above the ground (Fig. 2.8.13). The tube is partially filled with a coolant (refrigerant), such as ammonia or liquid carbon dioxide. The thermosiphon freezes the ground in winter
due to the temperature difference between the relatively warm ground (a few degrees below zero) and the air, which is 20–40 °C colder. The liquid refrigerant at the bottom of the pipe evaporates due to the higher soil temperature, causing the soil to cool. The refrigerant vapour then rises upwards and condenses in the cold atmosphere above ground, after which it flows back downwards and the process repeats. The thermosiphon thus transports cold underground, lowering the soil temperature by a few degrees more than would otherwise occur, and this is enough to ensure that the ground will not melt in the summer. The thermosiphon does not operate in the summer, because the air is warmer than the ground and the refrigerant inside the pipe does not circulate. During the summer the metal pipe conducts heat into the ground, but this effect is weaker than that achieved in the winter. This is a way of freezing the ground under roads and pipeline supports,
and even under large buildings. But the thermosiphons much be installed no more than about 1 m apart (Fig. 2.8.13).
It would be wrong to think that thermosiphons offer an easy solution to the problem of melting permafrost. They need to be replaced often, and despite their simplicity, they are expensive. It has been estimated that permanent freezing of the ground under gas pipeline supports in Russia would require spending of 10 billion US dollars!
Also thermosiphons are only a temporary measure, since they can only lower the temperature of the ground by a few degrees and will be powerless against more intensive warming. Roads will have to be mounted on special supports sunk deep into the ground – essentially, building an overpass on piles, which will increase construction costs by many times (Fig. 2.8.14).
It is not always possible to ensure that the ground stays frozen, and freezing technologies are helpless in the face of storms and intensive coastal erosion. In more and more cases it is proving impossible to save buildings and infrastructure and the only solution is to move people elsewhere.
Another important point is that large amounts of greenhouse gases are released from the tundra soil in the process of permafrost melt, increasing the greenhouse effect and speeding up global warming.
Weather anomalies in the Arctic
You know already that wind as well as temperature must be taken into account when assessing the weather. Extreme cold without wind is far better than a powerful blizzard, which makes it almost impossible to do anything useful outdoors – even to travel from one place to another. Working in blizzards is dangerous and difficult. Strong winds are becoming increasingly common in the Arctic, requiring the use of ever greater quantities of special equipment, clothing, safety gear and supplies to cope with prolonged snowstorms.
Humidity levels in the Arctic have increased, often leading to an alternation of thaws and frosts. This means that roads, bridges and power lines are often covered with a layer of ice, leading to more frequent accidents and breakdowns. Buildings and structures deteriorate more quickly due to the action of water and ice on micro-cracks. Water can penetrate the tiniest crack and then expands when it turns to ice, also expanding the crack. The ice melts, more water flows in, the new water freezes and the crack expands even more. The more often this cycle is repeated,
the faster the building deteriorates.
Low-lying regions, such as the Yamal Peninsula are increasingly affected by powerful spring floods, when huge territories are inundated with water to a depth of a metre or more. Yamal is now experiencing more snowfall and these large quantities of snow are now melting more quickly in the Arctic spring. Another problem in Yamal is the penetration of sea water into ground water, which leads to rapid erosion of the underground sections of all kinds of buildings.
How does climate change affect the indigenous peoples of the North?
Native peoples in the Arctic are suffering as a result of climate change, since their way of life and traditional livelihoods are directly dependent on climate conditions. Hunting, fishing, gathering of natural harvests and reindeer herding provide people with food, are the main source of income and are very important for preserving the traditions and culture of these peoples and of the territories where they live.
Reindeer herding is an important part of the livelihood and way of life of the natives of the Far North. More frequent thaws due to climate change mean that the ground is often covered by a layer of ice, which makes it hard for reindeer to find and eat lichens. Melting of the permafrost,
changes in snow conditions and earlier melting and later freezing of river ice are disrupting reindeer migration routes between winter and summer pastures. Changes in reindeer migration routes and reduction in populations of marine animals, hunting of which is part of the way of life of people in the Far North, are forcing people to seek new sources of food and income.
What can be done to help the indigenous peoples of the Arctic to adapt to changing climate conditions?
1) Carry out information campaigns among the local population on climate change and its possible consequences so that they can prepare to address the challenges.
2) Develop eco-tourism in these areas.
3) Raise the availability of health care in the Far North, especially in remote areas and villages, and ensure reliable supplies of heat and electricity.
What about the positive effects of a warmer climate?
It is true that climate change in the Arctic creates some opportunities. Less money has to be spent on heating, reduction of ice cover in the Arctic Ocean means that it can be used as a sea route between Europe and Japan and China and back. Infrastructure for ship traffic needs to be built along the northern sea route, including beacons, rescue equipment for emergency response, and harbours where ships can ride out storms or take shelter in case of the sudden appearance of ice.
The increasingly unstable Arctic climate and overall warming will also bring more frequent blizzards and sudden fluctuations of temperature.
The heating season can be shortened, but more unpredictable weather means that we must learn to adjust heating levels based on the real temperature outside the window and not the date on the calendar. That will mean installing regulators on radiators, so that residents can adjust the temperature in their homes as required. Russian housing services are not ready for this, it will call for extra work and equipment.
1. Where is climate warming happening faster: in the world as a whole or in the Arctic?
2. Why does the air temperature increase rapidly when ice fields in the Arctic break up in the spring to reveal open water?
3. Why are polar bears affected by shrinkage of the ice packs? Do they need ice?
4. What is the danger currently threatening seals in the White Sea?
5. Why is melting of the permafrost dangerous for buildings?
6. How does climate change affect the life of indigenous people in the Arctic? What could be done to help them adapt
to the changing conditions?
Task 1. Experiment
Purpose of the experiment: To observe how the volume of water changes when it freezes.
Materials: Airtight glass bottle, water. The experiment: Fill the glass bottle with water, seal it and put it in the freezer. What happened to the bottle when the water froze? Why did this happen? Draw a parallel with the
processes caused by permafrost.
Task 2. Experiment
Purpose of the experiment: To observe changes in the physical properties of materials when they freeze and thaw.
Materials: A plastic or paper box containing sour cream. Note. Soil that has frozen and then thawed will not be the same as it was before freezing. Ice layers may appear in it, which will divide into water and soil when thawing occurs. Sour cream behaves in a similar way when it is first frozen and then thawed. The experiment: Take a paper or plastic package of sour cream. Put it in the freezer. When the cream freezes, it will not be as a single piece: layers of ice will appear. When its thaws the sour cream divides into a white liquid and a thicker white substance (after it has been stirred this mixture regains the appearance of sour cream and it is perfectly eatable).