Sunday, June 20, 2021, 00:06
The greenhouse effect has always been present on earth and has also changed. To talk about him, Remember the three forms that the heat must be transferred: driving, convection and radiation (thermal). The last one, the way the heat of the sun reaches the earth, does not need any material medium. Moreover, let’s not forget that all bodies, at a temperature above absolute zero (-273ºC), broadcast thermal radiation. There are three majority effects related to the radiation that comes from the sun. On the one hand, By crossing the atmosphere, a small part is absorbed and another is reflected; The rest, majority, reaches the earth’s surface. This is most absorbed and heated the surface. Another part is reflected, crosses the atmosphere and goes to empty space. Moreover, like all bodies, the earth broadcasts thermal radiation. Use that energy balance, together with the distance from the earth to the sun, The surface temperature of the nature can be calculated. The result gives approximately 18 degrees below zero. However, the average temperature of the earth is approximately 15 degrees above zero. This 33 -degree discrepancy can have two explanations. Or the calculations are badly done, something that does not happen, or there is a phenomenon that is not considered. That phenomenon is the greenhouse effect. Let’s see what it consists of.
The earth is surrounded by the atmosphere. The gaseous part, together with the aerosols, only absorbs a small part of the thermal radiation broadcast by the sun, a source with high temperature. However, it absorbs a lot of radiation when it is emitted by a source with a low temperature. That is why an important part of the thermal radiation that is emitted by the earth is caught by the atmosphere, mainly by the low layers, the rest goes to empty space. This absorption produces its heating and therefore that of the earth’s surface. This is the greenhouse effect: the collection, through the atmosphere, of a part of the thermal energy broadcast by the earth. If this absorption is taken into account in the above calculations, the result is achieved that of the 15 degrees of the surface of the planet. This means that the atmosphere increases the temperature of the earth about 33 degrees and makes life possible. Now the question is: which gases from the atmosphere give rise to the greenhouse effect?
Science tells us that nitrogen and oxygen, which are 99%, absorb nothing. The remaining 1% is responsible for increasing the temperature 33 degrees. This means that small changes to the share of these minority gases can lead to important temperature changes. Of these are the most common water vapor and carbon anhydride (CO2). The amount of water vapor depends on the temperature: at more temperature, greater evaporation. That is why CO2 is the most important greenhouse regulator. We have the tools to write another day about the greenhouse effect through people and its consequences.
