In the early sixties a notable American scientist performed a series of experiments with the aim of bringing physics to children and to the public in general. His name was Professor Julius Sumner Miller and one of his experiments is significant today in the face of global warming and melting ice.
Professor Miller was no popular opportunist, his experiments were often accompanied by the most abstruse and technical calculations. However, he always maintained that the the inherent beauty of nature and science was not to be found in abstract theorizing but in contemplation and wonder.
In one of his experiments he placed ice cubes and a thermometer in a beaker of water and beneath the beaker (on a stand) was placed a bunsen burner. Surprisingly, as the ice melted above the tremendous heat input the temperature within the beaker did not rise. But when the ice finally melted the temperature increased markedly until it boiled.
The explanation of this is quite technical. In fact no thorough understanding of the phenomenon exists to this day (the problem quickly transforms into one of causation and change). But, in short, it appears that melting ice "absorbs" huge quantities of heat from the surroundings. This prevents a recordable rise in temperature and creates a "heat deficient enviroment".
Data shows that despite large ice losses in the northern hemisphere there is no recordable temperature rise. This can be confirmed by the modelling performed at the Oakridge laboratory. In fact, large drops in temperature are recorded in winter.
The "warming"/"change-of-state"/"heat-deficiency" cycle is at present an unconfirmed hypothesis. But if it is true the future temperatures in the northern hemisphere may very well oscillate between values that destroy land life.