What is the global warming?

Images satelitales indicate that every year vanishes up to 4 % of the cap of ice in the poles of our planet. The World Wide Fond for Nature (WWF) foresees, in addition, an increase in the temperature of between 4 and 7 °C in the next 100 years. In such conditions the north pole might melt completely at the end of the present century, notices the teacher Peter Wadhams, in whom for example if Grooenlandia, which is shaped in 85 % by ice, should come to deretirse completely, the level of the sea would increase in 7 m. An alone meter of increase would put in danger 17,000 million persons who live in the low regions.

Some specialists predict also other consequences: the enormous masses of water of thaw it would affect the marine currents, since the concentration of salt would diminish in the oceans.