Page 5 - Environmental_Climat change

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1.2 Types of greenhouse gases

Gases impacting on the greenhouse effect:

• Steam - Steam has the greatest impact on the greenhouse effect. Its content in the earth’s atmosphere
is very diverse and ranges from 40 to 95, depending on the cycle of water circulation in the environment
(evaporation, condensation, sublimation, and resubmission). Steam is 95% responsible for the greenhouse
effect, and its presence in the atmosphere is almost completely independent of human activity.

• Carbon dioxide - The presence of carbon dioxide in the air is a natural phenomenon because, among
other things, it is released when breathing and taken during photosynthesis. Unfortunately, since the
industrial revolution, the concentration of this gas in the atmosphere has increased from less than 10% to
about 30%. This is happening mainly in highly developed countries, because carbon dioxide is the result of
burning large quantities of fossil fuels.

• Methane - is another greenhouse gas, which is produced both by natural processes and by human
activity. It is produced naturally by anaerobic processes, but is also formed in termites, swamps and oceans.
Methane retains heat much more than carbon dioxide, but its duration is shorter so it is less present in the
atmosphere.

• Fluorinated greenhouse gases (HFCs) - Are mainly produced in industrial processes. They do not arise
naturally. Human activity contributes to their formation. They are a serious threat to the environment
because they have a high capacity to bind heat and remain in the atmosphere for thousands of years.