Chemistry / Greenhouse effect

Greenhouse effect

The greenhouse effect is a natural phenomenon caused by the concentration of gases in the atmosphere, which form a layer that allows the passage of sunlight and the absorption of heat.

This process is responsible for keeping the earth at a proper temperature, ensuring the necessary heat. Without it, surely our planet would be very cold and the survival of living things would be affected.

How does the greenhouse effect occur?

When the sun's rays reach the earth's surface due to the greenhouse gas layer, around 50% of them are trapped in the atmosphere. The other part reaches the earth's surface, warming it and radiating heat.

Greenhouse gases can be compared to insulators because they absorb part of the energy radiated by the Earth.

What happens is that in recent decades the release of greenhouse gases due to human activities has increased considerably.

With this accumulation of gases, more heat is being trapped in the atmosphere, resulting in increased temperature. This situation gives rise to global warming.

Drawing of how the greenhouse effect occurs

To get an idea, the greenhouse effect can be compared to what happens inside a parked vehicle, with the windows closed and receiving direct sunlight. Although glass allows sunlight to pass through, it prevents heat from escaping, increasing the temperature inside.

Greenhouse gases

Greenhouse gases

The main greenhouse gases are:

  • Water vapor (H 2 O): Found suspended in the atmosphere.
  • Carbon Monoxide (CO): Colorless, flammable, odorless, toxic gas, produced by burning in low oxygen conditions and by the high temperature of coal or other carbon rich materials such as petroleum derivatives.
  • Carbon Dioxide (CO 2 ): expelled by the burning of fuels used in oil and gas-based motor vehicles, the burning of coal in industries, and the burning of forests.
  • Chlorofluorocarbons (CFCs): composed of carbon, chlorine and fluorine from aerosols and the refrigeration system.
  • Nitrogen Oxide (N x O x ): set of compounds formed by the combination of oxygen and nitrogen. It is used in internal combustion engines, ovens, kilns, boilers, incinerators, the chemical industry and the explosives industry.
  • Sulfur Dioxide (SO 2 ): It is a dense, colorless, non-flammable, highly toxic gas formed by oxygen and sulfur. It is used in industry mainly in the production of sulfuric acid and is also expelled by volcanoes.
  • Methane (CH 4 ): colorless, odorless gas and if inhaled is toxic. It is expelled by cattle, that is, in the digestion of herbivorous animals, decomposition of organic waste, fuel extraction, among others.

What are the causes of the greenhouse effect?

As we have seen, the greenhouse effect is a natural phenomenon, but it is intensified due to the increasing burning of fossil fuels that represent the basis of industrialization and many human activities.

Forest fires to transform their areas into plantation, livestock and pasture also contribute to the increase of the greenhouse effect.

Greenhouse Effect and Global Warming

The consequence of the intensification of the greenhouse effect in the atmosphere is global warming .

According to scientific research, the average temperature of the earth over the last hundred years has risen by about 0.5 ° C. If the current rate of air pollution follows in the same proportion, it is estimated that between 2025 and 2050, the temperature will increase by 2.5 to 5ºC.

Warming the earth will result in the following effects:

  • Melting of large ice masses of the polar regions, causing sea level rise. This could lead to the submersion of coastal cities, forcing people to migrate.
  • Increase in cases of natural disasters such as floods, storms and punctures.
  • Species extinction.
  • Desertification of natural areas.
  • Most frequent episodes of drought.
  • Climate change can still affect food production as many productive areas can be affected.

Another problem associated with the presence of polluting gases in the atmosphere is acid rain . It results from the exaggerated amount of fossil fuel combustion products released into the atmosphere as a result of human activities.

Learn more about the relationships and differences between the Greenhouse Effect and Global Warming .

How to avoid the greenhouse effect?

To warn about the situation of the greenhouse effect and global warming, several countries, including Brazil, signed the Kyoto Protocol in 1997.

Prior to that, the Montreal Protocol was signed in 1987. The main purpose is to reduce the emission of ozone depleting products.

Some individual and collective action tips also contribute to reducing the greenhouse effect, they are:
  • Take short walks on foot or by bike;
  • Give preference to public transportation;
  • Use recyclable products;
  • Save electricity;
  • Perform selective collection;
  • Reduce consumption of beef and pork;
  • Make composting of organic material.