Save the rainforest – protect the climate!

The tropical rainforest is the most species-rich area on earth: a green wonder of jungle giants, lianas and ferns, inhabited by colourful birds, butterflies and many other animals. But every day huge areas of the rainforest are cut down. This does not only mean the end of many species. Clear-cutting is also a major problem for our climate!

Around two percent of the land area is still covered by tropical rainforest today, especially in the Amazon region, in the African Congo Basin and in South Asia. But this unique ecosystem is disappearing: Individual giant trees are felled to extract precious tropical woods. Large areas of forest fall victim to slash and burn to create pastures for cattle or fields for the cultivation of coffee, oil palms and soya. Every year, about 200,000 square kilometres of rainforest are destroyed in this way. This area is larger than the West African state of Senegal!

With the rainforest, about a hundred animal and plant species disappear every day. And the deforestation is also changing our climate. For forests store large amounts of carbon dioxide. If they are destroyed, the stored carbon dioxide is released into the atmosphere. There, 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.

Biofuel is harmful to the climate

Biofuel from palm oil, soybeans or rapeseed has a greater impact on the climate than previously assumed. This has been proven by scientific studies. Because rainforests are cleared for the cultivation of energy crops. And the destruction of the primeval forests releases gigantic amounts of carbon dioxide 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.

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 on the basis of 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.

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 and the atmosphere warms up.

So will we soon be swimming in swimming lakes instead of sledging in winter? Hard 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 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 down the rise of carbon dioxide in the air.

The greenhouse effect

The problem begins when we further increase the amount of greenhouse gases in the atmosphere. This happens mainly 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.

A shell of gas

Seen from space, it appears like a fine bluish veil that wraps 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.

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 air envelope is vital for us – but what is it actually made of?

The atmosphere is a mixture 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 – gases that only occur in the atmosphere in traces. These trace gases include methane, nitrogen oxides and, above all, carbon dioxide, or CO2 for short. Although the proportion of CO2 is quite small, this trace gas has a huge influence on our earth’s climate. This can be seen in the greenhouse effect, which heats up our planet.

The fact that the Earth has an atmosphere at all is due to gravity. It holds the gas molecules on 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 metres above sea level, this can become unpleasantly noticeable for people: They suffer from altitude sickness with shortness of breath, headaches and nausea. Extreme mountaineers who want to climb high peaks like the 8,000-metre peaks of the Himalayas therefore usually take artificial oxygen with them on their tour.