What is global pollution

Global change

Visible from above

Anyone looking at the earth from above can see global change: lakes are drying up, glaciers are melting, huge areas of forest have been cleared, deserts are spreading and cities are sprawling. Global, i.e. worldwide, change is often only viewed from the environmental point of view, but it means much more.

Since the 1980s, the term has stood for the profound changes on our planet. It includes climate changes, changes in land use, global environmental damage, the world's population development and the loss of biodiversity. In short: everything that belongs to the earth system, influences one another and is dependent on one another.

The disappearance of the forests

Before humans intervened, around 60 percent of the earth's land surface was covered with forest, scientists estimate. Today it is only half of it - and the trend is falling.

Although mankind also began to cut down forests when they settled down, it was not until the age of industrialization that forests were systematically used or eliminated. So it only took around 150 years to destroy what had been created over thousands of years.

In the past, the main causes of deforestation were the extraction of arable land and the use of wood. Today there is a very considerable number of causes that have one main reason: profit.

Forest areas are being cleared on a large scale in Asia, South America and parts of Africa in order to gain arable land for soy, palm oil, wheat or sugar cane. Primitive forests have to give way to quickly regrowing trees such as pines or eucalyptus, the wood of which is used for the paper industry. The pasture industry, which caters to the increasing consumption of meat around the world, also requires huge areas.

According to Welthungerhilfe, 28 hectares of forest are lost every day, around 270,000 trees are felled every day for toilet paper and disposable towels alone.

In addition, there is damage to the forest through the extraction of raw materials, pollutants or incorrect management. Most of the damage occurs in countries in the so-called Third World. The products to which the forest falls victim, however, are intended for others: for the rich industrialized countries.

The deforestation has devastating consequences: Forests are vital as CO2 stores and oxygen producers. If they are cut down, for example, a considerable amount of carbon dioxide is produced during the slash and burn process, which also pollutes the atmosphere.

Cleared areas warm up much faster than forest areas, which in turn has a negative effect on the climate. And last but not least, biodiversity disappears irretrievably with the forests.

Attempts to preserve the forests have so far only brought individual successes. In the northern hemisphere, forest shrinkage has come to a standstill in some countries, and some are even recording moderate growth. However, this cannot compensate for the overexploitation in other areas, for example the loss of tropical forests, which have the greatest biodiversity on earth.

The desert is advancing

Man is devastating the earth in the truest sense of the word. Deforestation, overfertilization, excessive grazing, overuse by agriculture, incorrect irrigation methods are some of the main causes for which humans are responsible.

If nature can no longer regenerate itself, arid and semi-arid areas quickly turn into desert areas and bodies of water dry up. If, in addition to overuse by humans, there is a drought or a longer climatic change, a catastrophe quickly ensues - for the residents of the area, but also for nature.

The best-known example of this is certainly the expansion of the desert in the Sahel at the beginning of the 1970s. Overgrazing is the main cause of desertification in Africa; in Asia it is mainly massive deforestation.

A third of the world's land surface is at risk from desertification - and with it a significant part of the arable land. According to the United Nations, around twelve million hectares of land are already being destroyed every year, an area as large as Austria and Switzerland put together.

Here, too, nature is taking revenge: biodiversity continues to decline, usable areas are being lost and ultimately the people in the regions affected are suffering. It mainly affects poorer countries, whose populations are particularly dependent on the use of natural resources. Food shortages and drinking water are worsening, and in some areas the soil is also contaminated by pollutants, which in turn leads to diseases.

Functioning countermeasures already exist, but often the means or the population do not have the knowledge to implement them. Sustainable management, the restoration of rural social systems, and avoiding irrigation-intensive plants and monocultures are some of the approaches.

To prevent further desertification, low walls are built in some places to hold back the little rainfall, or arable areas are planted with trees to protect them from erosion and to reduce evaporation.

The seas - a source of life and a rubbish dump

They are the origin of all life on earth, habitat for countless animal and plant species and an important source of food for humans. Not so long ago they were considered inexhaustible - today it looks different.

Some seas, such as the Mediterranean, are completely overfished, and many species are threatened with extinction due to intensive fishing. Fishing methods such as bottom trawling also destroy the seabed and valuable coral reefs.

It is not just food that attracts people: The seas offer a previously unknown amount of raw materials - precious metals, diamonds, ores, lead, mercury and more. Manganese tubers, potato-sized tubers at a depth of over 4000 meters that contain various metals, are of particular interest for raw material mining.

The best-known raw materials that have been mined so far are natural gas and crude oil. This, too, leaves enormous traces in the marine ecosystem: During extraction, for example, large amounts of non-degradable pollutants enter the water.

And there is something else in the oceans that doesn't belong there: garbage. In the mid-1990s, the American captain Charles Moore discovered a huge carpet made of plastic waste in the middle of the Pacific.

In 2010 the garbage carpet had already reached the size of Europe. The plastic is ground up, at some point washed ashore or swallowed by birds and fish - and thus ends up in the food chain. The dangers posed by this new "continent" of rubbish cannot yet be assessed. Similar rubbish carpets have now been discovered in the Atlantic and the North Sea.

But garbage is by no means the only problem: Above all, the carbon dioxide that is stored in the oceans makes the oceans more acidic - which has devastating consequences for flora and fauna. At the same time, the oceans are warming up as a result of climate change, and sea levels are rising.

Today it is believed that the warming of the oceans is contributing to the fact that storms and floods become more frequent. One thing is certain, however: countries with flat coastal regions and islands that rise only a few meters above sea level are threatened with sinking into the waves of the seas.

The treasures of the earth

The earth offers an immeasurable wealth of raw materials that ensure the survival of mankind and make life pleasant for many. But these raw materials are not inexhaustible, because they are used up much faster than they could be created.

Take oil, natural gas, coal and uranium, for example: It took millions of years for these raw materials, which are now important energy sources, to emerge. But it is already becoming apparent for all of them that the supplies will soon run out. And it only took mankind a few generations for that.

In the case of crude oil, it is assumed that the highest possible output, the "peak oil", has already been reached. After this point in time, the global output decreases and prices rise. It is estimated that it will take another 40 to 50 years until the deposits are completely exhausted, but then there will be no crude oil not only as an energy source, but also in the production of plastic, textiles, fertilizers and much more.

With the oil, the natural gas reserves are also coming to an end: they should last for at least 60 years; Coal, the use of which releases a particularly large amount of carbon dioxide, for at least another 200 years. According to data from the Organization for Economic Cooperation and Development (OECD) and calculations by Greenpeace, uranium, which is required for nuclear power plants, will still be available for about 60 years.

The treasures of the earth that mankind likes to use range from lush forests to precious metals, from sand and gravel to lead. In order to get hold of the coveted fabrics, mankind goes to great lengths and often leaves behind gigantic devastation.

Whole villages have to be relocated for open-cast lignite mining, and huge areas above ground are also dug up for open-cast copper mining. In underground mining, the search for coal or diamonds is dug to a depth of over 1000 meters. Above ground, spoil heaps are created, and in many areas the groundwater level is sinking.

In the extraction of gold and silver, cyanide and mercury are used - and the soil is permanently contaminated. Crude oil, the black gold, also leaves a poisonous trail: leaks during production contaminate the soil and water, accidents during transport on tankers repeatedly cause oil spills that ultimately devastate entire stretches of coast.

Those who suffer are not only the environment, which often does not recover over a long period of time, but also the population, whose habitat is being permanently destroyed.

Urban growth continues unabated

Mankind feeds on what is produced in rural regions. But many are drawn to the cities to live. More than half of the world's population now lives in cities, in the USA it is as much as 79 percent of the population.

At the same time, the world population is growing rapidly: in 1950 there were around 2.5 billion people worldwide, in 2019 there were 7.7 billion. As the world population grows, so do cities, and new urban areas emerge.

Cities are certainly the most radical transformation of the world, but their land use is not the real problem. Caring for residents is a real problem, especially in developing countries. Food and water have to be fetched from the surrounding area.

Often the infrastructure - for example the supply of water and energy, garbage and sewage disposal - cannot keep up with the increasing number of residents. The result is huge slums with inadequate hygiene and residents who often live below the subsistence level. Nevertheless, the rural exodus continues unabated in many countries.

The growth of the cities also affects the wider area: excessively large water withdrawals cause entire cities such as Mexico City to sag by the meter or permanently remove the vital moisture from the surrounding area.

In addition, huge amounts of wastewater make the drinking water available in some cases unusable. If the groundwater level in coastal cities sinks due to overuse, the drinking water threatens to become too salty due to the ingress of seawater.

In addition to the problems caused by humans, large cities are also threatened by natural hazards: These include heat waves and drought waves, hurricanes, floods and earthquakes. Such events cause devastating damage in industrialized countries and have a particularly strong impact where many people live in one space.

The metropolitan areas are threatened by another danger that is being accelerated by globalization: infectious diseases. Today they can spread around the globe within a few weeks and strike where a particularly large number of people are in a small area: in the cities.