The permafrost thaws

The frozen soils of the Arctic are thawing faster than previously assumed due to climate change. This could release huge amounts of the greenhouse gas methane into the atmosphere. This would further accelerate the warming of the Earth.

Permafrost soils extend over huge areas in the northern hemisphere. They are mainly found in large parts of Siberia and Alaska. Their name comes from the fact that they are frozen all year round – until now, anyway. But the earth’s temperatures are rising. For some years now, the frozen soils in the far north have been warming up, starting to thaw and turning into huge swamps.

Scientists suspect that the thawing permafrost could accelerate climate change. This is because the soils contain methane, a gas produced by microorganisms. This greenhouse gas has about 20 to 30 times the effect on the climate as carbon dioxide. In addition, large amounts of carbon are stored in the frozen soil. As temperatures rise, a vicious cycle begins here: if the permafrost thaws due to climate change, methane and carbon dioxide enter the air. The greenhouse gases warm the atmosphere, the earth heats up, the ice melts – and climate change is self-reinforcing.

So far, researchers disagree on how quickly the permafrost will thaw. The question of how much greenhouse gases will actually be released in the process is also still unresolved.

Koala bear in climate change

Bleak prospects for the koala bear: The cute marsupial is massively threatened by climate change. The greenhouse gas carbon dioxide makes the leaves of its favourite food inedible: Eucalyptus leaves become leathery and inedible due to the rising CO2 content in the air. Because their nutrient content is reduced, the koala has to eat much more eucalyptus to become full. This is just as true for other marsupials and marsupial-like animals. Many other animal species are also directly threatened by climate change, especially in the polar regions. The ringed seal and emperor penguin are losing their habitat due to the receding ice. And the Arctic beluga whale is finding less and less prey. What can be done? The World Conservation Union (IUCN) emphasises that individuals are not powerless. Everyone can reduce their carbon dioxide emissions and take action to protect the climate.

Climate disaster at the North Pole

The polar bear’s floe is melting away under its paws. Global warming is causing the sea ice around the North Pole to disappear, and faster and faster. The greenhouse effect, caused by the emission of carbon dioxide and other climate-damaging gases, is to blame.

In 1980, the Arctic Ocean was still frozen over on 7.8 million square kilometres, an area about the size of Australia. Within 30 years, the ice area has shrunk to about half that size! The ice sheets are already thawing in spring. If it continues like this, the “eternal ice” will soon have disappeared completely.

For the polar bear, this is a catastrophe. Environmental organisations fear that polar bears and seals will become extinct within the next 20 years. Migratory birds are also losing their breeding grounds in the Arctic due to the changed climate.

Another marine predator, on the other hand, is already finding new habitat: because the ice continues to recede, the killer whale can now also go in search of food high up in the north.

Shortcut through the Arctic Ocean

The ice in the Arctic Ocean is melting dramatically. This has opened up a trade route between Europe and Asia: the Northeast Passage. This sea route runs along the northern coast of the continents of Europe and Asia. In the past, large transport ships could only sail through this route in high summer. This was because the Northeast Passage was frozen almost all year round and far too dangerous because of the masses of ice. Ships travelling between Rotterdam and Tokyo therefore took the long route through the Mediterranean, the Suez Canal and around India.

New satellite images show that the route through the Arctic Ocean is becoming more and more ice-free. This makes the journey easier for ships – even without icebreakers. This saves time and transport costs, because the route through the Arctic Ocean is several thousand kilometres shorter than the old route through the Suez Canal.

Alarm in the Alps

It is the mightiest of all Alpine glaciers: the Aletsch Glacier in the Bernese Alps is over 23 kilometres long. Its ice cover is up to 900 metres thick. For now! Because the white splendour of the glaciers could soon be history.

For decades, researchers have been observing that the ice masses are becoming smaller. On average, they are losing half a metre of thickness per year. Climate change, which is causing the earth’s temperatures to rise, is to blame: In the increasingly warmer summers, more ice melts than is added in the cold season. The hot summer of 2003 was particularly hard on the ice giants: At that time, large parts of the glaciers melted away. In the meantime, it is even feared that the Alpine glaciers could disappear in as little as 30 years.

This would be a great loss for the landscape of the Alps – and a disaster for tourism: many winter sports resorts live from skiing on glaciers. If ice and snow melt, tourists will also stay away. In addition, there will be problems with the water supply if the glaciers die. This is because huge amounts of fresh water are stored in their ice masses. Many places would then have to transport their drinking water expensively and from far away.

Cling film for glaciers

To protect their glaciers from rising temperatures, the Austrians have come up with something: they cover their glaciers in summer with plastic cling film. The white film, just under four millimetres thick, is supposed to reflect the sun’s rays and thus prevent the ice and snow from melting. And indeed: Glacier researchers confirm that the film greatly reduces melting.

Glacier foils are now also being used in Switzerland and Germany. The Zugspitze, too, now regularly gets a “sun hat”. Climate protectionists criticise that this may slow down the melting of the ice for a while, but it will not stop global warming.

Record CO2 emissions

Global emissions of carbon dioxide have never been as high as they are today. In 2010, it even rose more sharply than ever before. This has now been announced by the US Department of Energy. The figures exceed even the worst fears.

For years, experts have been warning about the speed of global warming. Apparently without success: for the proportion of the climate-damaging gas carbon dioxide in the air is rising rapidly. Especially in the industrialised countries, it is constantly pouring out of chimneys and exhaust pipes. The new figures are alarming: in 2010, the world emitted a total of over 33,500 million tonnes of carbon dioxide. That is 1,900 million tonnes more than in the previous year, an increase of six percent!

According to the US study, China and India are primarily responsible for the horror increase. Both countries are growing economically. They get their energy mainly from coal-fired power plants – and thus produce a lot of CO2. Overall, China is the record holder for greenhouse gas emissions, followed by the USA, Russia and India.

Policies on global climate protection have failed completely so far. China and the USA refuse to curb their CO2 emissions. Russia, Canada and Japan also refuse to comply with directives when the main polluters balk at meeting international limits. Bad for the climate, as the new study clearly confirms based on the figures.

The Keeling Curve

The world’s first CO2 measuring station was opened far away from car exhausts and factories: In 1958, the US climatologist David Keeling began to regularly measure the carbon dioxide content of the air on the volcano Mauna Loa on the island of Hawaii. This location was chosen quite deliberately. Because neither chimneys nor forests influenced the result, an average value of the trace gas in the air could be measured here. A second station in Antarctica also fulfilled these conditions. After two years, Keeling presented his results to the world: The level of carbon dioxide in the air was rising! In the following years, Keeling continued to fight for regular CO2 measurements of the atmosphere. With success: the result is the so-called Keeling curve, a collection of data that records the carbon dioxide content of the air to this day and documents the significant increase in CO2.

The greenhouse effect

In a greenhouse, vegetables or flowers can thrive even when it is cold outside. This is because greenhouses are made of glass. The glass – or even a transparent film – allows the short-wave rays of the sun to reach the inside unhindered: The air warms up. For the long-wave heat radiation, on the other hand, the glass is impermeable, so the heat can no longer escape. That’s why it’s cosily warm in a greenhouse.

Something similar is happening on a large scale on Earth. The greenhouse gases carbon dioxide (CO2) and water vapour are naturally present in the atmosphere. Water vapour enters the air through evaporation, carbon dioxide through us breathing out. Volcanic eruptions also contribute to the natural carbon dioxide content of the air. Both gases have the same effect as the glass of a greenhouse: they allow the short-wave rays of the sun to reach the earth. At the same time, like an invisible barrier, they obstruct the long-wave heat radiation on its way back into space. The heat accumulates and the atmosphere heats up.

Without this natural greenhouse effect, hardly any life would be possible on Earth, because it would be far too cold for most living things. Instead of the current average temperature of plus 15 degrees, there would be an icy minus 18 degrees Celsius. The earth’s surface would be frozen!

The problem starts when we further increase the amount of greenhouse gases in the atmosphere. This happens primarily through the burning of oil, natural gas and coal. Heating our homes, driving cars, burning rubbish: Carbon dioxide is emitted during all these processes. This CO2 has the largest share in the man-made greenhouse effect. But the cultivation of rice or cattle farming also intensify the effect: large amounts of methane (CH4) – also a greenhouse gas – are produced in the stomachs of ruminants and in the flooded soils of rice fields. In addition, nitrous oxide, ozone and fluorocarbon are also greenhouse gases. Because all these gases slow down the heat radiation of the earth, the temperatures on our globe continue to rise.

The consequences of climate change

Climate change is already particularly visible in the polar regions. Just a few decades ago, the Arctic Ocean was largely covered by ice. But due to rising temperatures, this ice cover is melting: in the last 30 years, its area has almost halved. At the same time, the ice cover is becoming thinner and thinner. Climate researchers have calculated that the ice could melt completely in the next 20 years. Sea levels would rise by several metres as a result. But not only the ice sheets at the poles are melting. The glaciers in the high mountains are also losing mass.

Because the sea level is rising due to the melting of the ice, ever larger coastal areas are being flooded. Low-lying island states, such as the Maldives in the Indian Ocean or Tuvalu in the Pacific, are therefore increasingly threatened by storm surges. And not only the sea level, but also the water temperature is rising with climate change. As a result, more water evaporates and more water vapour is stored in the air. This increases the greenhouse effect, which heats up the atmosphere even more. In addition, this increases the risk of storms such as heavy rain and hurricanes.

In dry regions, deserts are spreading due to rising temperatures. More and more droughts are causing rivers to dry up and previously green areas to wither. In the south of Spain, for example, the usual rainfall that is urgently needed for agriculture has been absent for years. And the water shortage in southern Europe continues to worsen.

All these consequences of climate change can already be observed now. Climate researchers are trying to calculate how it will continue with the help of computer models. But the future is difficult to predict because so many influences determine our climate. For example, the melting of glaciers dilutes the salty sea water with fresh water. The salinity of the sea, however, drives ocean currents. So what could happen if the lower salinity causes the warm Gulf Stream to break off? Will it then initially become colder instead of warmer in Europe? What would happen if the permafrost thaws in the far north? Will tonnes of the greenhouse gas methane then escape from the ground? And will this accelerate climate change?

So far, no one can answer that exactly. But with all the unanswered questions, one thing seems certain: If we do not drastically reduce our carbon dioxide emissions, temperatures on this globe will continue to rise.

Global warming

The earth is getting warmer and warmer. In the last hundred years alone, the average temperature has risen by almost one degree Celsius. The main reason for this warming is the increased amount of carbon dioxide in the air. This increase in CO2 is mainly caused by the industrialised countries through the burning of oil, gas and coal.

Plants, on the other hand, have a protective effect on the climate. They can absorb carbon dioxide from the air and convert it into organic compounds during photosynthesis. Tropical forests store a particularly large amount of carbon dioxide. However, because large areas of forest are being cleared in the tropics, this storage function is becoming smaller and smaller. Because where there are no more trees, no more carbon dioxide is extracted from the air. The greenhouse effect increases, the atmosphere warms up.

So will we soon be swimming in the bathing lake instead of sledging in winter? Difficult to predict. Scientists are trying to calculate how many degrees Celsius the earth will heat up in the future with the help of computer models. According to these models, the average temperature on Earth could rise by another one to six degrees by the year 2100. How the temperature curve will actually develop depends above all on whether the proportion of carbon dioxide continues to rise.

Serious consequences of climate change can already be seen: Ice masses are melting, sea levels are rising, storms and droughts are increasing. This makes it all the more important to reduce greenhouse gas emissions, especially CO2. Because this trace gas remains in the atmosphere for a long time. Only if we blow less of it into the atmosphere can man-made climate change at least be slowed down.

Some industrialised countries have therefore committed themselves to reducing their greenhouse gas emissions and not to exceed certain CO2 levels. But despite a whole series of climate summits, the global community has not yet succeeded in slowing down the rise of carbon dioxide in the air.

Why are there ice ages and warm periods? Natural climate changes

At the height of the last great ice age, it was bitterly cold. So cold, in fact, that a third of the land area disappeared under thick ice sheets. All that happened about 20,000 years ago. Over the millennia, temperatures rose again. Today we live in a warm period and only ten percent of the land surface is still iced over. But it was far from the first climate change on our planet. Since the earth was formed 4.6 billion years ago, it has sometimes been warmer and sometimes colder – without any human involvement. But why?

Climate researchers have been trying to find out what triggers natural climate changes for a long time. One explanation is that the earth “wobbles” a bit when it orbits the sun. This can be thought of as similar to a spinning top, but on a much larger scale. Both the tilt of the Earth’s axis and its orbit shift over thousands of years, in a regular cycle. This “egging” also changes the amount and distribution of the incoming solar energy. Over long periods of time, this causes temperatures to fluctuate, leading to ice ages and warm periods.

The distribution of the continents also plays a role in the fluctuations. Because their position has constantly shifted in the course of Earth’s history. When large land masses reached the North or South Pole, enormous amounts of ice could accumulate there. The ice reflected a large part of the sun’s rays and it became even colder. Only when the continent moved away from the pole again did the temperatures rise and an end to the ice age was in sight.

The composition of the atmosphere also affects the climate. The greater the proportion of greenhouse gases, such as carbon dioxide or water vapour, the more the atmosphere heats up. Its gas mixture can be changed by natural processes, for example by a volcanic eruption. When a volcano spews fire and ash, tiny particles are thrown high into the air, the aerosols. They reflect the sun’s rays before they reach the earth’s surface. The temperature on Earth drops – at least for a short time. Thus, the eruption of the Tambora volcano in 1815 was followed by a “year without summer”. At that time, snowstorms swept over the east coast of North America in the middle of the warmest season of the year. The result was catastrophic crop failure.

In contrast to these natural climate changes over the course of history, the current climate change is caused by humans themselves. The fact that the average temperature has been rising for a good 150 years is mainly due to the fact that humans are producing more and more carbon dioxide.

Polar Regions – Arctic and Antarctic

The largest ice surfaces on earth are around the North Pole and the South Pole. Because of their special location, the polar regions receive very little sunlight and solar heat, and the summers are particularly short there. That is why it is always extremely cold there – temperatures of up to minus 70 degrees Celsius prevail throughout the year. The cold has allowed huge masses of ice to form in the polar regions.

The Arctic ice around the North Pole covers a large part of the Arctic Ocean in winter. It then covers an area of several million square kilometres. For the most part, this is a layer of ice that floats on the sea. In addition, the Arctic ice covers the northern areas of Europe, Asia and North America.

In contrast, the South Pole is located on a continent, Antarctica. Antarctica is the coldest place on earth. Its land mass is almost completely buried under a shell of ice and snow up to 4 kilometres thick. Almost three quarters of the fresh water on Earth is stored in this ice.

Humans, animals and plants have adapted to life in the “eternal ice”. Polar bears or reindeer, for example, protect themselves against the cold with a layer of fat and thick fur. Only a few people inhabit the Antarctic, the Arctic is somewhat more densely populated. The best-known inhabitants of the Arctic are the Inuit in North America and Greenland, but there are also the Lapps in northern Scandinavia and indigenous peoples in northern Siberia. In the past, they lived there as nomads and moved around with dog sleds. Today they use snowmobiles and many of them live in cities.

Hardly anything grows in the ice deserts around the poles because of the great cold. The ground between the polar regions and the cold temperate zone is permanently frozen to great depths. This ground is therefore also called permafrost after the Latin word “permanere” for “to last”. It only thaws slightly a few months a year. Then particularly hardy plants such as mosses, lichens or dwarf shrubs can grow on it. This region around the polar regions is also called subpolar tundra.

The polar regions are the coldest areas on earth. It is also here that it is apparent that the Earth is heating up: for some years now, researchers have been observing that the ice masses of the Arctic and Antarctic are melting. The consequences of this warming cannot yet be precisely estimated. But it is already clear that many habitats are threatened by the melting of the poles.