CO2 – the most important greenhouse gas

Air pollution

CO2-carbon dioxide (carbon dioxide)

Carbon dioxide exists in the environment in free and bound states. It is found in the air, mineral springs, volcanic fumes. It is a colorless, odorless gas with a sour taste. Under normal conditions, its density is 1.53 times that of air. It dissolves fairly well in water. In liquefied form, it is a colorless liquid. Solidified CO2 (dry ice) is used as a freezing agent.

It accounts for about 0.04% of the air volume, but in large urban areas its concentration can reach 0.08%. For humans, it becomes harmful if the amount of its concentration exceeds 0.2%.

Carbon dioxide is formed in the process of combustion, with free access to oxygen. This process can be written as:

C + O2 = CO2

Carbon dioxide enters the atmosphere from natural sources and through human-induced processes:

  • Natural:
    • Quick carbon cycle
      • CO2 is one of the products of respiration;
      • It is formed in the decomposition of organic matter;
    • Slow carbon cycle
      • Is a product of oxidation during volcanic eruptions
      • Participates in the exchange process in the relationship: atmosphere – ocean (absorption and emission of
  • Caused by human activity:
    • The process of burning fossil fuels (in the energy industry, transportation);
    • Emissions in the building materials, electrical machinery, pulp and paper industries;
      Emissions in the refining and petroleum industries;
    • Deforestation (deforestation) causes a decrease in natural CO2 neutralizers and this contributes to an increase in the concentration of this gas in the atmosphere.

Other greenhouse gases include:

  • methane (CH4);
  • nitrous oxide (N2O);
  • ozone (O3);
  • water vapor (H2O);
  • hydrofluorocarbons (HFCs);
  • perfluorocarbons (PFCs);
  • sulfur hexafluoride (SF6).

These gases affect the greenhouse effect to varying degrees. This impact is expressed by the so-called greenhouse potential, which is measured in relation to one molecule of CO2. Thus, one molecule of CH4 balances 28 molecules of CO2, and thus absorbs 28 times more heat than a molecule of carbon dioxide. A very important feature of greenhouse gases (besides water vapor, whose molecules live from 4 to 10 days) is also their lifespan, which ranges from 12 to 50,000 years. However, of all the greenhouse gases, it is carbon dioxide (in addition to water vapor) that is the most important gas, accounting for 25% of the greenhouse effect.

Characteristics of greenhouse gases
Concentration in years 1000-1750280 ppm700 ppb270 ppb000
Concentration for the year 2000370 ppm1850 ppb330 ppbThey are steadily growingThey are steadily growingThey are steadily growing
Life expectancy in the atmosphere30-9512121100123200
Greenhouse potential12826510200176023500