Drive less car, heat less, eat less meat, reduce the use of energy such as in the case of using power tools ( read a review – Best DeWalt impact driver for 2021). There are numerous proposals to counteract climate change. The measures are measured by how much they reduce carbon dioxide (CO2) emissions.
Greenhouse Effect and Global Warming
Because the more of it is in the atmosphere, the hotter it will be on our planet and thus global warming can be an issue. Since the industrial revolution, the chimneys have been bringing more and more exhaust gases into the air, and since then the concentration of CO2 has been rising steadily – with consequences for the climate. Today it is around one degree warmer than at the end of the 19th century. Scientists fear that this trend could continue.
The climate models say that the increase could lead to an average temperature of around three degrees higher by the end of the century.
We need to talk about it
Climate skeptics claim that the low level of CO2 has no effect
The cause of anthropogenic warming is the so-called greenhouse effect, which is caused by the earth’s atmosphere and its components. A look at the atmospheric layers also shows, however, that only a fraction of this is carbon dioxide (around 0.04 percent by volume). The majority make up nitrogen, oxygen and argon (around 99 percent). So how can so many years of international climate negotiations and countless media reports relate to this small percentage?
The argument of the climate skeptics may be plausible at first glance due to the low proportion of CO2 (around 0.04 percent by volume). But the low value belies the climate impact of carbon dioxide. After all, more important than the concentration is the effect, just as a person can eat kilos of sugar, but a few nanograms of poison can be enough to kill.
A little CO2 is also sufficient
To understand why CO2 and other greenhouse gases play an important role in our planet, one can, for example, imagine the earth without an atmosphere.
Our moon, for example, has no atmosphere. The solar radiation heats the surface of the planet to more than 100 degrees Celsius during the day and drops to around minus 160 degrees at night. Without the atmosphere, there would also be a much greater temperature difference on earth. Researchers have calculated that the average temperature on earth would be minus 18 degrees. In fact, it is 15 degrees Celsius – around 33 degrees more.
The fact that the temperatures are neither so extreme during the day nor at night is due to our atmosphere, which also acts as a protective shield. First of all, our atmosphere prevents all solar radiation from hitting the earth. Overall, less than half of the solar radiation reaches the earth’s surface. Clouds, for example, reflect a quarter of the solar radiation directly back into space, while the masses of snow reflect another part.
The rest of the energy reaches the earth’s surface, is converted there, and sent back towards space in the form of thermal radiation. What is important here is that what reflects back from the earth’s surface is different radiation than that which comes from the direction of the sun. The heat radiation emanating from the earth can, however, be reflected between the atmosphere and the ground and, in a certain sense, be trapped by greenhouse gases.
These gases (water vapor, CO2, methane, and others) prevent thermal radiation from immediately escaping into space. Instead, some of it is sent back to earth again – and this is where the climate impact of CO2 and others lies: the chemical structure of the gases in the atmosphere is decisive. Greenhouse gases are made up of three or more atoms. Carbon dioxide, for example, from one carbon and two oxygen atoms.
Unlike oxygen or nitrogen (two atoms), these gas molecules are sensitive to certain types of radiation. The decisive factor is their wavelength. The radiation energy is absorbed and sets the molecules in motion, specifically in vibrations. During movement, in turn, energy is released, which is given off as heat radiation in different directions – about half of it also in the direction of the earth’s surface.