Pregrado

GLOBAL HEATING

I change climatic or global Heating, group of alterations in the terrestrial climate that you/they can affect to all the parameters climatic (precipitations, temperature, nubosidad, etc.). The climate has never been static, but rather along the history of the Earth diverse climatic changes caused by natural causes have taken place.
The scientific prevén that the globalheating will continue to a rhythm without precedents in the history of the Earth and prevén a heating still bigger in the XXI century that will depend on the future emissions of gases of effect hothouse. In a supposition with higher emissions, in which the emissions continue being increased at a significant level along the century, the scientific prevén for the year 2100 a heating of 2,4 to 6,4centigrade grades. On the other hand, in a supposition with less emissions, in the one that these they grow slowly until arriving to a maximum in 2050 to descend later, the scientists predict a heating from 1,1 to 2,9 ºC for the year 2100.

The thaw of the poles and of the glaciers, as well as the heating of the oceans, would cause an increase of the volume of the ocean and, therefore, an elevationof the level of the sea, what would cause a flood of the coastal areas and even of whole islands. It is expected that the patterns of rains change and you prevent more rains in higher altitudes (more near the poles) and less in the subtropical areas (as the Mediterranean and the south of African). The changes in the temperatures and in the precipitations they could damage the crops, altering theproduction of foods in some parts of the world. The vegetable species and animals will move to the poles or places of more height looking for colder temperatures and those that are not able to make it will extinguish. The increment of the levels of dioxide of carbon in the atmosphere also causes an increase of the acidity of the oceans, damaging the marine ecosystems.

The consequences thatit can carry this phenomenon are so preoccupants that many scientific leaders and more and more also the politicians, the businessmen and other citizens, request the international cooperation and an immediate action to counteract the problem.

THE EFFECT HOTHOUSE

The energy that lights and it heats the Earth it comes from the Sun. The solar radiations of short wave that it emits the Sun, asthe visible light, penetrate in the atmosphere and they are absorbed by the surface, heating the Earth. In turn, the surface of the Earth liberates some this heat in form of infrared radiation of long wave.
Great part of this infrared radiation returns to the space but a part remains caught in the terrestrial atmosphere, retained by certain atmospheric gases as the vapor of water, the dioxideof carbon and the methane. These gases absorb and they reflect the heat irradiated by the Earth in the same way that the glass in a hothouse, for what you/they receive the name of gases of effect hothouse.
The gases of effect hothouse that constitute less than 1% of the total of the atmospheric gases, only offer to the Earth certain isolation. If it was not for the effect hothouse, the halftemperature of the terrestrial surface would be around -18 ºC and the ice would cover the Earth of a pole to other, disabling the development of the life in our planet.
Although the parameters that govern the climate and the processes that cause the global heating are known and they are based on scientific principles, the experts continue working to know certain details of the climatic system andtheir answer to the increase of the gases of effect hothouse. The scientific uncertainty is unavoidable in such a complex system as the one that controls the climate in the Earth. However, the advances in the mensuration techniques, analysis and modelación have contributed to clarify numerous uncertainties in the last years.

For example, it is not clear why the tendency to the heating...