Global warming: what it is and what causes it
The term Global warming signifies an increase in the temperature of the earth’s climate, now spread across all areas of the planet, discovered during the last century. This has led to a devastating transformation of the environment, ecosystem and society, which in the long term, may result in consequences such as the melting of glaciers, an increase in the frequency of hurricanes and the extinction of many animal and plant species.
Even though scientists have devoted several decades to the study of the natural factors which influence our climate, the causes of global warming may be only be explained by taking into account the greenhouse gases introduced into the atmosphere by man. This is not a simple task, and has been entrusted by the UN to the Intergovernmental Committee on Climate Change (ICCC).
It is in fact thanks to the ICCC that today we have a much clearer idea of the factors involved in global warming. This has been made possible by the fact that the members of the Committee meet periodically (every 2 to 3 years on average), with the aim of analyzingthe latest research and providing thorough reports on the evolution of this phenomenon.
Scientists discovered almost immediately that the main causes of global warming can be divided into various categories of greenhouse gases introduced into the atmosphere by humans in different ways: although the greatest quantity is produced by combustible fossil fuels used for vehicles and in factories, the gas which causes the greatest increase in temperature is carbon dioxide (CO2).
In addition to CO2, there are other gases which affect global warming such as:
- methane which is given off by waste dumps and produced in agriculture during the digestion process of cattle;
- nitrous oxide used in fertilizers;
- gases used in industrial processes and refrigeration;
- and deforestation which reduces the number of trees able to absorb CO2.
- Even though some gases produce a much greater increase in temperature compared to that caused by CO2 (methane for example has a heat-producing capacity 20 times greater than CO2), the latter influences the increase in atmospheric temperature more than all the other gaseous mixes, because it is present in a higher overall percentage.
It is for this reason that when academics explain the effects of the various gases, they generally refer to greenhouse gases in terms of the equivalent quantity of carbon dioxide.
Translated by Joanne Beckwith
