MELTING OF THE POLES: EVOLUTION, CAUSES, CONSEQUENCES, SOLUTIONS - ENVIRONMENT - 2025

The melting of the poles or thawing is the loss of the mass of ice at the ends of the planet as a result of global warming. In this sense, it has been noted that in the north pole (Arctic) sea ice has decreased and in Antarctica (south pole) glacial ice decreases at a rate of 219,000 million tons / year.

The ice found at both poles is of a different nature and the Arctic is predominantly sea ice while Antarctica is a continent covered in glacial ice. Sea ice is frozen seawater and glacial ice is the product of compaction of layers of snow on land.

Arctic ice cap. Source: NASA

When sea ice melts, it does not raise the water level, while glacial ice, being above the land mass, runs into the sea and can raise its level. On the other hand, the melting of the poles generates changes in water temperature, affecting the ecology of the area and the circulation of large ocean currents.

The melting of the poles is caused by the increase in temperature of the atmosphere, the sea and the land. The temperature of the planet has been increasing as a consequence of the development of the Industrial Revolution from the middle of the 18th century.

Likewise, large tracts of land have been deforested to build factories, cities and expand farming to generate more food. Therefore, CO2 emissions into the atmosphere have increased and its fixation by plants, corals and plankton has decreased.

Atmospheric CO2 is a greenhouse gas, which contributes to increasing the average temperature of the planet. This has altered the natural balance and has generated the melting of the world's sea ice and glaciers.

The consequences of the melting of the poles can be very serious because meteorological processes and the movement of marine currents are altered.

Among the possible solutions to avoid the melting of the poles is to reduce the emission of greenhouse gases such as CO2, methane and nitrogen dioxide. Likewise, the deforestation of the forests and the pollution of the oceans must be reduced.

For this, a development model is required that is sustainable, based on clean energy with low consumption and in balance with nature.

Evolution from the 18th century (Industrial Revolution) to the present

Paleoclimatic studies (of ancient climates) made at both poles indicate that for 800,000 years there were no alterations in the natural cycles of heating and cooling. They were based on CO2 concentrations of 180 ppm (parts per million) in the cold phase and 290 ppm in the hot phase.

However, in the mid-nineteenth century, an increase in the concentration of atmospheric CO2 began to be noticed, exceeding the limit of 290 ppm. This has resulted in an increase in the average temperature of the planet.

The industrial Revolution

The socio-economic expansion of Europe began around the year 1760 in England and spread to America, it is known as the Industrial Revolution. This development was the cause of the increase in the concentration of CO2 due to the burning of fossil fuels, especially coal.

First Industrial Revolution: Coal

The energy base of the initial phase of the industrial revolution was coal, coupled with a series of scientific discoveries and changes in the social structure. Among these stands out the use of machines whose source of energy was steam heated by burning coal.

In addition, coal was used for the generation of electricity and in the steel industry. In this way, the imbalance in the world climate began, which would later be reflected in various environmental problems.

Oil and gas

It is considered that the invention of the internal combustion engine and the use of oil and gas led to a second Industrial Revolution between the late 19th and early 20th centuries. This has resulted in an accelerated increase in CO2 added to the atmosphere as a result of human activities.

20th century: jump in CO2 concentration

By the mid-20th century, industrial development encompassed most of the planet and CO2 concentrations began to grow at an accelerating rate. In 1950 the CO2 concentration exceeded 310 ppm and by the end of the century it reached 380 ppm.

The melting icecaps

Melting glacial ice in Antarctica. Source: Vincent van Zeijst

Among the many consequences of the economic revolution, the melting of sea and land ice stands out. Antarctica is estimated to have lost three billion tons of ice since 1992.

This loss has accelerated in the last six years, which is estimated at an average of 219,000 million tons / year.

During 2016 the temperature of the Arctic increased 1.7 ºC and for 2019 it is estimated that the ice of the north pole covered only 14.78 million square kilometers, This is 860,000 square kilometers below the maximum average recorded between 1981 and 2010.

Causes

The melting of the poles is the product of the increase in the planet's temperature, known as global warming. A study conducted by the NSIDC (US National Snow and Ice Data Center) in 2011 estimated that the temperature of the Arctic increased between 1 to 4ºC.

On the other hand, NASA has indicated that the average temperature increased by 1.1 ºC compared to the 1880/1920 period (1.6 ºC on land and 0.8 ºC at sea). There are considered to be two main causes of the increase in global temperature:

-Increase in CO2 emissions

Natural cycle

According to paleoclimatic studies, about 8 glacial periods have occurred on the planet in the last 800,000 years. These periods of low temperatures have alternated with warm periods and this alternation has coincided with variations in the concentration of CO2 in the atmosphere.

These variations were the product of a natural mechanism based on the supply of CO2 to the atmosphere by volcanic eruptions and its capture by the growth of corals in warm shallow seas.

It has been estimated that in warm periods concentrations of 290 ppm of CO2 were reached and in cold periods 180 ppm of CO2.

Greenhouse effect

On the other hand, CO2 acts as a greenhouse gas since it prevents the exit of thermal radiation from the Earth into space. This results in an increase in the temperature of the planet.

Artificial cycle

From the middle of the 19th century, this natural cycle of heating and cooling began to alter due to human activities. In this sense, by 1910 the concentration of CO2 had reached 300 ppm.

In 1950 the level of carbon dioxide reached 310 ppm, in 1975 it was 330 ppm and at the end of the 20th century 370 ppm.

The fundamental cause of this increase in the concentration of CO2 in the atmosphere is mainly due to the burning of fossil fuels (coal and oil). In this way, large amounts of CO2 captured by plants millions of years ago are being released into the atmosphere.

-Decrease in carbon sinks

Vegetable masses, plankton and corals fix carbon in their development processes by extracting CO2 from the atmosphere. Therefore, they behave as carbon sinks by making it part of their body structures.

The destruction of forests and the pollution of the seas causing the death of corals and the decrease of plankton has reduced the rate of carbon fixation.

The forests

Forests have been reduced by 436,000km2 in Europe since 1850 and have been replaced by cities, industries, agricultural fields or plantation forests with uniformity of species.

The loss of vegetation cover increases the temperature by 0.23 ºC in the affected areas due to the increased impact of solar radiation on the earth's surface. The albedo effect of the forest (ability to reflect solar radiation) is 8 and 10% and when they are cut down, this effect is lost.

On the other hand, when vegetation fires occur, fixed carbon is released in the vegetation mass that also accumulates in the atmosphere. In this image you can see the deforestation in an area of ​​the Amazon:

The oceans

Oceanic pollution causes acidification of marine waters and toxic substances are deposited that have caused the death of about 50% of corals. In addition, this acidification can affect the plankton that captures most of the carbon.

Hole in the ozone layer

The ozone layer is an accumulation of this form of oxygen (O3) in the upper layers of the stratosphere. Ozone reduces the amount of ultraviolet radiation that penetrates the Earth, which helps maintain temperature and prevents the harmful effects of this radiation.

In 1985 scientists detected a hole in the ozone layer over Antarctica, which represents an important factor in the melting of ice in this area. This is caused by various gases emitted into the atmosphere as a result of human activities such as chlorofluorocarbons (CFCs).

Consequences

The increase in the concentration of greenhouse gases in the atmosphere generates an increase in temperature. Therefore, the melting of the poles is caused with serious global consequences:

-Rising sea levels

The immediate consequence of glacial ice melting is sea level rise. For example, if all the Antarctic ice melted, the sea level would rise up to 70 m.

If this were to happen, much of the coastal cities would be flooded and the ecology of large areas could be altered. In Antarctica there are 13,979,000 km2 of frozen land surface and glacial discharges in the area have doubled between 2002 and 2006.

In the Arctic, the glacial ice that could cause sea level rise is found in Greenland. Other arctic areas with glacial ice include the Canadian archipelago, the Russian Arctic islands, the Svalbard and Jhan Mayen archipelago, and the continental Arctic region.

-Erosion of the Arctic coasts

Melted iceberg at Cape York (Greenland). Source: Brocken InagloryThis image was edited byUser: CillanXC

The Arctic Circle encompasses the coasts of: Greenland, Canada, the United States, Iceland, Norway, Sweden, Finland, and Russia. These coasts are known as soft coasts because they are not constituted by rocky substrate, but by permafrost.

Global warming causes the permafrost to melt and leaves the lower structure exposed to erosion. The areas most affected by erosion are Laptev, Eastern Siberia and the Beaufort Sea, in Alaska, in which their coasts already present a loss of up to 8 meters.

Also, the melting of permafrost releases large amounts of CO2 and methane that are trapped in the frozen snow layers.

-Alteration of atmospheric patterns

As sea level rises, evaporation is affected and therefore many meteorological events are altered. This can have various consequences:

Changing atmospheric circulation patterns and ocean currents

The oceanic temperature can be affected by the incorporation of masses of melt water (warmer than liquid marine water) from the melting of the poles. This can also affect the normal course of ocean currents.

In the case of the melting of the Arctic ice, the Gulf Stream will be affected. This current moves a large body of warm water from the Gulf of Mexico to the North Atlantic.

Therefore, thermal regimes can be altered and generate warmer air in the Arctic and Central America and cooler air in northwestern Europe.

Increase in the frequency of hot-cold alternation

Heat waves alternated with cold waves are becoming more and more frequent worldwide. In the case of heat waves, it is appreciated that they occur in smaller and smaller intervals and with longer duration.

Increased rainfall

As the polar ice melts, the mass of liquid water increases and the increase in temperature affects evaporation. As a consequence of this, rainfall increases, which can be increasingly torrential and occur more erratically.

Erosion and desertification

The increase in torrential rainfall and the greater frequency of alternation between cold and warm waves, can produce an increase in soil erosion.

Decrease in water resources

Polar ice is the largest reservoir of fresh water on earth. In such a way that its melting and mixing with seawater represents a significant loss of drinking water.

-Impact on biodiversity

The melting of sea ice in the Arctic Ocean and of permafrost on its coasts has a negative impact on the life habits of the species located in these areas. In addition, the climatic alterations that the melting of the poles globally brings about negatively affects the planet's biodiversity.

The vegetation

Tundra species, such as lichens and mosses, are affected by the alteration of freezing and thawing patterns during the year. On the other hand, the melting of the Arctic allows species from warmer latitudes to invade the tundra and displace native species.

The polar bears

Polar bear in Svalbard (Norway). Source: Arturo de Frias Marques

Polar bears are animals that live, hunt and breed on Arctic sea ice and are an emblematic case. Drastic reductions in sea ice in the summer are threatening their populations scattered across Alaska, Canada, Greenland, Norway and Russia.

Currently it is estimated that there are less than 25,000 specimens of polar bears in that entire region. These animals hunt seals in winter and spring to build up fat reserves that allow them to survive through the summer.

During the warmer period, polar bears have greater difficulty hunting the seals, since they move more easily. For their part, in the winter they are forced to surface when bears can more easily catch them.

The melting of the poles causes the ice to decrease and it also melts earlier in the season. This results in that polar bears can hunt fewer seals and are therefore less likely to survive.

The caribou

In recent decades, caribou populations have decreased by 50% due to the increase in temperature. Therefore, the melting pattern of the rivers that mark their migration cycles is altered.

All this promotes the invasion of vegetation from warmer lands that displaces the mosses and lichens that are the food of this species.

-Lifestyle changes and cultural loss

The Nenets

They are a Siberian ethnic group whose source of life is the herds of reindeer from which they obtain food, clothing, shelters and transport.

Reindeer mainly graze moss and lichens characteristic of these arctic areas, which have been reduced by the increase in temperature.

Inuit

It is an ethnic group that inhabits the coasts of Alaska and has traditionally depended on fishing and hunting for seals, whales and polar bears.

However, with global warming, sea ice is retreating and game populations are moving elsewhere. Therefore, the traditional knowledge and way of life of these communities is being lost.

On the other hand, species such as salmon and robins that are not part of the Inuit culture have begun to appear in these areas.

The sami

It is an ethnic group originating from the arctic coasts of Norway that is dedicated to herding reindeer, which forms the basis of its culture. Reindeer migrate to the coast before the rivers thaw, but their behavior patterns are altered by the melting of the poles.

Solutions

Reduction of greenhouse gas emissions

To stop the melting of the poles, a drastic reduction in greenhouse gas emissions is necessary. This decrease must be higher than the goals established (and not fully met) in the Kyoto Protocol.

This protocol is part of the United Nations Framework Convention on Climate Change (UNFCCC). It was agreed in Kyoto, Japan, in 1997 and sets quotas in order to reduce greenhouse gas emissions.

However, the economic interests of the countries that generate the most emissions have affected compliance with the Kyoto protocol.

Reforestation and protection of forest masses

The complementary measure to reducing emissions is to conserve existing forests and increase the area covered by them. However, the largest forest extensions are in developing countries that have expansion plans that lead to massive deforestation.

Developed countries have very small forest masses, as they were deforested during the establishment of the Industrial Revolution.

Control of pollution of the seas

The seas are the main carbon sink through corals, plankton, and fish, capturing around 50% of atmospheric carbon. For this reason, it is essential to guarantee ocean balance and reduce pollution of marine waters, mainly with plastics.

Geoengineering

Some scientists have proposed geoengineering alternatives, such as injecting sulfur aerosols into the polar stratosphere to generate global shading.

Sulfur aerosols reduce the input of solar radiation and therefore cool the Earth, but this could affect evaporation and reduce precipitation in some areas.

References

1. Arctic Program (2019). Arctic Report Card: Update for 2018. Effects of persistent Arctic warming continue to mount. Taken from arctic.noaa.gov
2. Becher M, Olofsson J, Berglund L and Klaminder J (2017). Decreased cryogenic disturbance: one of the potential mechanisms behind the vegetation change in the Arctic. Polar Biology 41: 101–110.
3. Eraso A and Dominguez MC (Seen on 07/11/2019). The thaw in the Arctic and the Antarctic. Pleistocene ice ages and current global warming.

   Taken from antarkos.org.uy.- Huettmann F (Ed.) (2012). Protection of the three poles. Springer. New York, USA. 333 p.

4. Pacheco-Pino S and Valdés-Cavieres C (2012). Environmental effect of the melting of the Arctic and its impact on tourism. Inter-American Journal of Environment and Tourism (RIAT) 8: 8-16.
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6. Wigley TML (October 2006). A combined mitigation / geoengineering approach to climate stabilization. Science 314: 452–454.