Oder: Kinderfragen sind gute Fragen. Z.B.: Warum fallen die Wolken nicht vom Himmel? Oder: Warum hat's eigentlich so viel Eis am Norpol? Letzteres haben sie jetzt in Barcelona - wo denn sonst - rausgefunden:

(<a href=www.alphagalileo.org target=_blank>alphagalileo) Ice has been building up in the Arctic for 2.7 million years. Until now, no-one has been able to prove what mechanism brought about this accumulation of ice. However, a team of international scientists led by Antoni Rosell, a researcher for the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona, and Gerald H. Haug of the Potsdam Institute for Climate Impact Research (Germany) has discovered the mechanism that set off the accumulation of ice. (...)
According to the research, the most important change during the period was a 7ºC increase in the difference between summer and winter temperatures within just a few centuries. The summers became warmer and the winters cooler, causing more water to evaporate from the sea into the atmosphere during the summer. The air became more humid and snowfall increased. When Winter set in, the sharp decrease in temperatures enabled ice to build up.
But what brought about this difference in temperatures? The researchers are the first to find evidence showing that this was caused by the stratification of ocean water, due to an increase in freshwater. This means that water mixed less than previously, forming layers of different densities in different strata and at different depths. When spring came, the layers closest to the surface began to heat up. Since the water did not mix, the temperature of those layers continued to rise, and increasing amounts of water evaporated. During the summer months, this effect intensified, as higher temperatures increase stratification; in winter, however, the water began mixing again, and temperatures dropped more than in previous years.

Damit harrt die Frage, warum die Wolken nicht vom Himmel fallen, immer noch ihrer Beantwortung. Freiwillige vor!