On the occasion of the celebration of World Environment Day on the 5th, the author points out the negative effects of man-made global warming.

Greenhouse effect: who has not heard of this phenomenon? In recent times and from different sectors, atmospheric pollution, mostly caused by human beings, has been analyzed, which implies a generalized rise in temperatures on the planet.

The Earth has specific conditions that make life possible, such as having a particular atmosphere: a layer of gases that envelops the Earth. It consists mainly of oxygen and nitrogen and traces of other elements such as carbon dioxide. Carbon dioxide, despite being in very high concentration leave , plays an essential role because it prevents the radiation that reaches us from the Sun from being returned in its entirety to space. It thus becomes a "kind of trap" that allows solar radiation, in the form of light, to pass through the atmosphere but prevents all the heat from escaping to the outside. In this way, thermal conditions suitable for life exist on the Earth's surface, with an average temperature of 15°C. A natural greenhouse effect is produced without which life would not be possible.

But what would happen if carbon dioxide starts to be emitted indiscriminately into the atmosphere as result from industrial processes, or from the use of fossil fuels in vehicles, or if forests are cut down? The answer is common: the balance in the atmosphere is disrupted. Thus, the concentration of carbon dioxide increases, sunlight continues to enter, but it becomes increasingly difficult to dissipate the heat into space: the Earth progressively warms up, enhancing the natural greenhouse effect. In view of this status, the experts of the Intergovernmental Panel on Climate Change estimate that the Earth's surface temperature will rise by 1.5 to 4.5°C during the 21st century (IPCC-Climate Change 2014. Japan).

Global warming raises sea levels
The consequences of global warming are not yet defined but there are several models that simulate the result of a temperature increase. The report of the group of experts published in 2014 adds effects to those concluded in the report of 2007 (IPCC 2007. Switzerland). Among others, they cite the following: changes in vegetation; negative impacts on forests due to pests, diseases and fires; increase in energy expense for refrigeration (air conditioning); detrimental effects on fauna and flora acclimatized to extremely cold areas such as Alaska or Northern Canada, changes in precipitation in the form of rain and snow and reduction of permafrost (frozen areas) and glaciers.

But undoubtedly, the best known effect of global warming is the increase in sea level due to the melting of the polar ice caps. In fact, the 2014 report establishes an increase of between 26 and 81 centimeters over the next 85 years, values even higher than those indicated in the 2007 report . Rising sea levels would imply the destruction of coastlines, more severe flooding and seawater intrusion into freshwater aquifers, reducing the availability of this precious resource resource.

The reflection of all the above leads inevitably to a theory: the Gaia Hypothesis (James Lovelock, 1969). This theory proposes a natural equilibrium in the planet, so that all elements are conditioned by this equilibrium. If man breaks it by releasing, for example, the carbon dioxide contained in fossil fuels, nature tends to regulate itself towards a new equilibrium by altering the existing one.

Conserving the environment, optimizing resources and, especially, raising awareness of the delicate natural balance, are the challenges to be met in today's unbridled consumerist society, especially on dates as globally recognized as June 5: Environment Day. The Earth is wise, let us respect its balance.