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Definition greenhouse effect

The greenhouse effect is the process by which the atmosphere of a planet passes solar radiation from the sun, but instead prevents or hinders the output of thermal energy on the planet.

It is called the greenhouse effect because of the similarity with the operation of the greenhouses that are able to retain heat inside. The operation is not exactly the same, but if that is very similar. The difference is that the greenhouse uses glass and no gas atmosphere to retain heat. So this natural phenomenon has been called greenhouse effect.

When talking about the greenhouse effect we almost always refer to the greenhouse effect on Earth, but also occurs similarly to other planets like Venus and Mars.

Operation of the greenhouse

At the time that solar radiation reaching the Earth's atmosphere of this radiation is reflected while another portion is absorbed and enters the atmosphere. Most of the radiation that has managed to enter the atmosphere reaches the surface causes the surface terrestre.Esto warm, and that some of this heat is referred as radiation but at wavelengths greater than the original solar radiation.

From the infrared radiation that the Earth's surface refers only an important part (about 90%) get back through the atmosphere and will go into space. The remaining radiation heats the atmosphere gas and heat energy stays there, so that the planet is enveloped by a set of hot gases that contribute to heating. The atmosphere has the characteristic that most readily absorbs infrared radiation output to visible radiation from the Sun, and that's what makes the Earth is hotter than it would be without an atmosphere.

This event is what makes the planet Earth reaches temperatures that allow it to be 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 the heat does not stay trapped in the atmosphere, Earth freezes.

Issue of greenhouse

We've all felt at one time that something like that fuels fósilescontribuyen to the generation of greenhouse gases in a negative context. The greenhouse effect itself is not a negative thing (indeed necessary), which is negative is that the gases emitted artificially enhance excess natural greenhouse effect.

These gases not present naturally in the atmosphere contribute to the retention of heat and keep the planet 30 ° C warmer than if this layer does not exist.

The fact that the burning of fossil fuels (coal, oil, natural gas, ...) or a forest fire, carbon dioxide. If the concentration of CO2 in the atmosphere increased significantly, could increase the strength of the effect invernadero.Aunque not known accurately all the factors involved in the greenhouse effect, this has begun to worry popular opinion in the late twentieth century.

Increasing the temperature of the planet would have important effects on developing life: would endanger the composition, resilience and productivity of natural ecosystems, alter climatic regions and ocean currents, with potentially important consequences for human activities. Within the scientific community there is no consensus on the exact consequences. Still the most alarmist thesis argue that these problems are as follows:

  • Desertification and drought causing hunger pandemics.
  • Deforestation, which further increases the change.
  • Melting Antarctic ice, which causes sea level rise, causing floods submerging coastal cities.
  • Destruction of ecosystems.

Greenhouse gases

Those responsible for this effect in the atmosphere are greenhouse gases. List them in order of importance

  • Water vapor (H2O)
  • Carbon dioxide (CO2)
  • Ozone (O 3)
  • Other gases lesser extent.
    • Methane (CH 4)
    • Nitrous oxide (N2O)
    • Sulfur hexafluoride (SF6)
    • CFC

These gases have a strong ability to absorb heat energy in the infrared region of the spectrum.

Kyoto Protocol

The Kyoto Protocol is an international agreement that aims to limit emissions of greenhouse gases globally. The protocol comes from international concern about global warming that could increase emissions of these gases uncontrolled.

The agreements were carried out in the Kyoto protocol in 1997 were:

  • The signatories commit industrialized countries to reduce greenhouse gas emissions by 5% in the period 2008 to 2012 compared to 1990.
  • The rich countries must reduce their emissions by between 25% and 40% for 2020 compared to 1990.
  • The long-term negotiation, states that the increase in temperature should be below two degrees above pre-industrial levels. This objective will be reviewed because it does not exceed 1.5 degrees.
  • Adapted from less industrialized to take on the disasters related to climate change.
  • The 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 a control system and international verification, but must be done so that it is not instructive, not punishable and respectful.
  • The industrialized countries should provide assistance to 30,000 million dollars over three years to 2012 and mobilize resources to $ 100,000 annually by 2020.
  • The aid will be channeled through a fund with 24 members and in which 12 come from rich countries and others.


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Last review: July 25, 2016