It is called the greenhouse effect because of the similarity with the operation of greenhouses that are capable of retaining heat inside. The operation is not exactly the same, but it is very similar. The difference is that the greenhouse uses glass and not gases from the atmosphere to retain heat. This is why this natural phenomenon has been called the greenhouse effect.
When we talk about the greenhouse effect, we almost always refer to the greenhouse effect on planet Earth, but it also occurs similarly to other planets like Venus and Mars.
What does the greenhouse effect consist of?
At the moment in which the solar radiation that reaches the Earth's atmosphere part of this radiation is reflected while another part is absorbed and enters the atmosphere. Most of the radiation that has managed to enter the atmosphere reaches the Earth's surface, which causes the surface to heat up, and to send part of this heat in the form of radiation, but at wavelengths greater than that of the Earth. original solar radiation.
Of the infrared radiation emitted by the Earth's surface, only a significant part (approximately 90%) will be able to go back through the atmosphere and out into space. The rest of the radiation heats the gases in the atmosphere and its heat energy stays there, so the planet is enveloped by a set of hot gases that contribute to heating it. The atmosphere has the characteristic that it absorbs outgoing infrared radiation more easily than visible radiation received from the Sun, and that is what makes Earth warmer than it would be without an atmosphere.
This event is what causes planet Earth to reach temperatures that make it suitable for life. The greenhouse effect is therefore a natural phenomenon of the atmosphere, without which life on Earth, as we know it, would not be possible. If heat is not retained in the atmosphere, the Earth freezes.
Why is the greenhouse effect a problem?
The greenhouse effect is not a problem for life on Earth. In reality, it is essential to retain solar heat and prevent it from freezing. The problem of the greenhouse effect appears when this natural effect is enhanced by natural causes. By increasing this effect through other types of gases, the Earth's temperature rises and negatively affects the species that live on it.
These gases not naturally present in the atmosphere contribute to heat retention and keep the planet 30 ° C warmer than if this layer did not exist. It is what is called global warming and one of the causes of climate change.
The fact that by burning fossil fuels (coal, oil, natural gas, ...) or by burning a forest, carbon dioxide is produced. If the concentration of CO 2 in the atmosphere increased significantly, it could increase the strength of the greenhouse effect.Although not all the factors involved in the greenhouse effect are known precisely, this has started to worry popular opinion at the end of the 20th century.
The increase in the planet's temperature would have important effects on the life that develops: it would jeopardize the composition, resilience and productivity of natural ecosystems, alter climatic regions and ocean currents, with possible important consequences on human activities. Within the scientific community there is no consensus on the exact consequences. Even so, the most catastrophic theses maintain that these problems would be the following:
- Desertification and droughts, which cause hunger pandemics.
- Deforestation, which further increases change.
- Melting of the Antarctic ice, which causes a rise in sea level, submerging coastal cities causing flooding.
- Ecosystem destruction.
What are the main gases that cause the greenhouse effect?
Those responsible for this effect on the atmosphere are greenhouse gases. We list them in order of importance.
- Water vapor (H 2 O)
- Carbon dioxide (CO 2 )
- Ozone (O 3 )
- Other gases in a smaller proportion.
- Methane (CH 4 )
- Nitrous oxide (N 2 O)
- Sulfur hexafluoride (SF 6 )
These gases have a strong capacity for absorbing heat energy in the infrared region of the spectrum.
What is the Kyoto Protocol and what agreements were made?
The Kyoto protocol is an international agreement that tries to globally limit greenhouse gas emissions. The protocol stems from international concern about global warming that could increase uncontrolled emissions of these gases.
The agreements that were carried out in the Kyoto protocol in 1997 were:
- The signatory industrialized countries undertake to reduce greenhouse gas emissions by 5% in the period from 2008 to 2012 compared to 1990.
- Rich countries must reduce their gas emissions by between 25% and 40% by 2020, compared to 1990.
- The long-term negotiation establishes that the temperature increase must be below two degrees with respect to pre-industrial levels. This objective will be reviewed because it does not exceed 1.5 degrees.
- Adaptation of the least industrialized countries to face the disasters related to climate change.
- Industrialized countries should promote strategies to lower carbon emissions, and developing countries should limit emissions with appropriate national plans and actions.
- The action plans must be submitted every two years to an international control and verification system, although they must be done in a way that is non-instructive, not punishable and respectful.
- Industrialized countries must provide aid of $ 30 billion over three years, until 2012, and mobilize resources up to $ 100,000 annually in 2020.
- Aid will be channeled through a fund with 24 members and in which 12 will come from rich countries and others.
How is the greenhouse effect related to solar energy?
Usually the concept of greenhouse effect is used globally to talk about an environmental problem on Earth. However, the same effect occurs in a certain area of solar thermal energy.
Solar collectors are used in thermal solar installations. The function of solar collectors or solar collectors is to capture heat from solar radiation. One type of these solar panels, the flat-bottom solar collector, is designed to recreate the greenhouse effect on a small scale and thus prevent heat from escaping from the solar collector. In this way, the performance of this renewable energy source is increased.