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 shrinking. 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 although this will slow down the melting of the ice for some time, it will not stop global warming.

What is a glacier?

Glaciers flow down from the mountains like white tongues. Others cover huge land masses as mighty sheets of ice. Glaciers consist mainly of ice and can be hundreds of metres thick and several kilometres long. Most of the fresh water on Earth is frozen into ice! But how do such ice masses come about in the first place?

Glacier ice forms where it is very cold all year round. Such low temperatures prevail far up in mountains, for example in the Alps. The snow that falls there does not even thaw completely in summer. The snow cover therefore becomes thicker and heavier. Under this load, the loose snowflakes are pressed over time first into grainy firn and then into dense ice.

Even in the areas around the North Pole or South Pole, more snow falls throughout the year than can thaw again. Glaciers then form, even in flat landscapes. The glaciers of the polar regions are thousands of metres thick. They have the shape of huge shields and are therefore called ice sheets.

Glaciers flow downhill very slowly under the weight of their own weight. Meltwater at their bottom makes it easier for them to glide over the ground. With their mass of ice, they also drag sand and rock fragments that have been blasted off the ground by frost.

If a glacier eventually advances into warmer regions, its ice melts. The meltwater runs off in a trickle; if there is a large amount of water, a river forms. If the meltwater collects in a hollow, it forms a glacial lake.

Mountain climate and altitudinal zones in the Alps

In the Alps and other high mountains of temperate latitudes, the altitudinal zones begin with the so-called hilly zone, where agriculture is still practised. Towards the summit, the mountain stage follows with mixed and coniferous forests. Above the tree line, only various dwarf shrubs and meadows thrive, which are often used as cattle pasture for alpine farming in summer. Above the snow line, vegetation is completely absent because cold, snow and ice prevent plant growth.

Mountains in other climatic zones also have such altitudinal zones. However, other plant communities thrive there and the altitude levels are shifted: for example, the snowline in the tropics is much higher than in the Alps.

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.

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? Would it then first 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.

The permafrost thaws
Arctic soils release greenhouse gases

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 intensifies itself.

So far, researchers disagree on how quickly the permafrost will thaw. The question of how much greenhouse gases are actually 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.

This is a catastrophe for the polar bear. 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.