|
 The greenhouse effect is a natural physical phenomenon that is essential to life on Earth. Without it, the average temperature of the Earth’s surface would be around -18°C, rather than the current 15°C. Among the gases of natural origin that contribute to the greenhouse effect, the most significant are water vapour and carbon dioxide (CO2) and, to a lesser extent, ozone (O3), methane (CH4) and nitrous oxide (N2O).
Intergovernmental Panel on Climate Change (IPCC), a group of scientific experts assembled in 1988 by the World Meteorological Organization and the United Nations Environment Programme, a growing number of observations reveal an overall global warming trend and several climate system changes. New elements confirm that most of the global warming observed in the last 50 years is due to human activity, with local repercussions known as “climate change”. The six most significant GHGs of anthropogenic origin, the use of which has not been previously regulated by any international agreement are: carbon dioxide (CO2); methane (CH4); nitrous oxide (N2O); sulphur hexafluoride (SF6); hydrofluorocarbons (HFCs); and perfluorocarbons (PFCs) The origin of these GHGs breaks down as follows:
Greenhouse Gas (GHG) | Origin | CO2 | Combustion of fossil fuels, linked to transport and the production of electricity or heat; certain industrial processes, and lastly from tropical deforestation. | N2O | Agriculture, the chemical industry and combustion activities. | CH4 | Agriculture, oil and gas activities, and waste management activities. | SF6
HFCs
PFCs | Certain specific industrial processes (manufacturing of aluminum or magnesium, the semi-conductor industry), and from aerosols, air conditioning and insulating foam. |
|
