The tropical rainforest is the most biodiverse area on earth: a green wonder of jungle giants, lianas and ferns, inhabited by colorful birds, butterflies and many other animals. But every day huge areas of the rainforest are cut down. This means not only the end of many species. Clearcutting is also a major problem for our climate!
About two percent of the land area is still covered by tropical rainforest, mainly in the Amazon, the African Congo Basin and South Asia. But the unique ecosystem is dwindling: Individual tree giants are felled to gain noble tropical woods. Large areas of forest fall victim to slash and burn to create cattle pastures or fields for growing coffee, oil palms and soybeans. There are about 200 characters per year.000 square kilometers of rainforest destroyed. This area is larger than the West African state of Senegal!
Along with the rainforest, about a hundred animal and plant species are disappearing every day. And deforestation is also changing our climate. Because large amounts of carbon dioxide are stored in the forests. If they are destroyed, the stored carbon dioxide is released into the atmosphere. As a greenhouse gas, it ensures that the earth continues to heat up. To prevent this, it is also important to preserve the tropical rainforest.
Loggers in Indonesia
Source: imago stock&people
Slash and burn destroys tropical rainforest
Source: imago stock&people
Slash-and-burn forest in Sierra Leone
Source: imago stock&people
Biofuel as a climate pollutant?
Biofuel is harmful to the climate
Biofuels made from palm oil, soybeans or rapeseed have a greater impact on the climate than previously assumed. Scientific studies have proven this. Rainforests are being cleared for the cultivation of energy crops. And by destroying the primeval forests, gigantic amounts of carbon dioxide are released into the air. This in turn increases the greenhouse effect – a reaction that biofuel should actually slow down. For this reason, the European Union now wants to restrict the use of biofuels.
The greenhouse effect is intensifying
Global carbon dioxide emissions have never been as high as they are today. In 2010 it has even increased more than ever before. This has now been announced by the U.S. 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: Because the proportion of the climate-damaging gas carbon dioxide in the air is rising rapidly. In the industrialized countries in particular, it is constantly pouring out of chimneys and exhaust pipes. The new figures are frightening: in total, the world lost more than 33.500 million tons of carbon dioxide are emitted. These are 1.900 million tons more than last year, an increase of six percent!
Can electric cars save the climate??
Source: imago stock&people
Lignite-fired power plants are among the worst climate polluters
The Keeling Curve
The earth is getting 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 CO2 increase is mainly caused by the industrialized countries by burning oil, gas and coal.
Burning oil, gas and coal increases the greenhouse effect
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 particularly large amounts of carbon dioxide. But 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, there is also no more carbon dioxide being taken out of the air. The greenhouse effect intensifies, the atmosphere warms up.
Forests can store carbon dioxide
So will we soon be swimming in swimming lakes in winter instead of sledding? 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 a further 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.
Swimming in January?
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, man-made climate change can at least be slowed down.
Signs of climate change: The ice masses of the Arctic are shrinking
Some industrialized countries have therefore pledged to reduce 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 the rise of carbon dioxide in the air.
Measure for climate protection: wind power
The greenhouse effect
In a greenhouse, vegetables or flowers can thrive even when it is cold outside. This is because greenhouses are built of glass. The glass – or even a transparent film – allows the short-wave rays of the sun to enter unhindered: The air heats up. The glass, on the other hand, is impermeable to long-wave heat radiation, so the heat can no longer escape. That’s why it gets toasty warm in a greenhouse.
In a greenhouse, plants grow even when the outside temperature is low
Something similar is happening on a large scale on Earth. The greenhouse gases carbon dioxide (CO2) and water vapor are naturally present in the atmosphere. Water vapor gets into the air by evaporation, carbon dioxide by 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 sun rays to penetrate to the earth. At the same time, like an invisible barrier, they hinder the long-wave heat radiation on its way back into space. The heat accumulates and the atmosphere heats up.
Water vapor traps heat on the earth
Without the natural greenhouse effect it would be much colder on earth
Without this natural greenhouse effect, hardly any life would be possible on earth, because it would be much too cold for most living creatures. Instead of the current average temperature of plus 15 degrees, the temperature here would be an icy minus 18 degrees Celsius. The surface of the earth would be frozen!
The greenhouse gas carbon dioxide is produced when we burn ..
The problem starts when we further increase the amount of greenhouse gases in the atmosphere. This is mainly done by burning petroleum, natural gas and coal. Heating your home, driving your car, burning garbage: Carbon dioxide is emitted during all these processes. This CO2 has the biggest share in the man-made greenhouse effect. But the cultivation of rice or cattle farming also increase the effect: in the stomachs of ruminants and in the flooded soils of rice fields, large amounts of methane (CH4) are produced – also a greenhouse gas. In addition, nitrous oxide, ozone and hydrofluorocarbon are also greenhouse gases. Because all these gases slow down the heat radiation of the earth, the temperatures on our globe continue to rise.
…for example from petrol.
What pollutes the air?
A thick haze hangs thickly overhead. Especially in big cities and urban centers, such a gray haze of fog is often seen. Here, the air quality suffers from the fact that lots of dust particles are whizzing around. Because they are too small to be seen with the naked eye, these suspended particles are also called fine dust. In addition to particulate matter, toxic gases such as carbon monoxide and sulfur dioxide float in the lower atmosphere and pollute the air.
Dirty air due to car exhaust fumes
A large part of these exhaust gases is produced by burning petroleum, coal and other materials. Cars, power plants, waste incinerators and residential heating systems blow a lot of dirt into the air. In addition, there is dust – from the streets, but also, for example, from factory farming. The "exhaust fumes" of farm animals also contribute to the fact that the air is getting worse and worse. But it is not always humans who pollute the air: Volcanic eruptions can also contribute to higher levels of particulate matter in the atmosphere.
Exhaust gases from industrial plants
The more pollutants there are in the air, the worse it is for our health: the respiratory tract can become diseased, and the circulatory system and brain are damaged. Not only humans and animals suffer from polluted air, but also plants are damaged: If too much carbon dioxide and sulfur oxide are suspended in the air, acid forms in combination with water (carbonic and sulfuric acid). What results is the so-called "acid rain", which causes the soil to turn sour. Plants growing on such soil become arid and die off. The talk is of "forest dieback. This can happen far from where the exhaust fumes enter the air, because the wind carries the acid rain clouds hundreds of kilometers away.
Forest fires can pollute the air…
Air pollution is particularly bad in cities with millions of inhabitants in India, Pakistan and Iran, or as in Mexico City. In Germany, there are regulations on how much air can be polluted. But even here the values are not always respected and car traffic continues to increase.
…as well as livestock
To keep the pollutants in the air low, it is therefore particularly important to have enough forests and parks to clean the air. Trees, like all green plants, absorb carbon dioxide from the air and produce oxygen, which is essential for life. "Green lungs" in large cities, i.e. green spaces and forests close to the city, are therefore particularly important for our health. And if you get on your bike more often instead of driving, you also help to keep the air clean.
"Green lungs": City park in Nuremberg
A shell of gas
Seen from space, it appears like a fine bluish veil around the Earth: the atmosphere. It is the envelope of air that surrounds our planet. Compared to the diameter of the Earth, this envelope is quite thin: If the Earth were the size of an apple, the atmosphere would be about the thickness of its skin.
The atmosphere provides oxygen for breathing
Without the atmosphere there would be no life on this planet, because plants, animals and humans need air to breathe. It protects us from the cold and from harmful radiation from outer space. It also allows meteorites to burn up before they can hit the Earth’s surface. This envelope of air is vital for us – but what does it actually consist of??
Only about one fifth of the air we breathe is oxygen
The atmosphere is a mix of different gases. A large part of this gas mixture is nitrogen: at 78 percent, it makes up almost four-fifths of the entire atmosphere. Only 21 percent consists of oxygen, which we need to breathe. The remaining one percent is made up of various trace gases – i.e. gases that only occur in the atmosphere in trace amounts. These trace gases include methane, nitrogen oxides and, above all, carbon dioxide, or CO2 for short. Although the proportion of CO2 is quite low, this trace gas has an enormous influence on our earth’s climate. This can be seen in the greenhouse effect, which heats up our planet.
On the peaks of the Himalayas the air is very thin
The fact that the earth has an atmosphere at all is due to gravity. It holds the gas molecules on the earth and prevents them from simply flying out into space. In fact, as altitude increases and gravity decreases, the air becomes thinner and thinner. At altitudes as low as 2000 meters above sea level, this can be unpleasant for people: He suffers from altitude sickness with shortness of breath, headaches and nausea. Extreme mountaineers who want to climb high peaks such as the 8000-meter peaks of the Himalayas therefore usually take artificial oxygen with them on their tour.