Bohemians live in alternative spaces, these are places that are not normally considered suitable for living in. They don't make wealth their priority. Money is only a means of survival, so they can live for their arts/craft/music/literature...etc.
What causes ice-ages? Fluctuations in the amount of insolation (incoming solar radiation) are the most likely cause of large-scale changes in Earth's climate during the Quaternary. In other words, variations in the intensity and timing of heat from the sun are the most likely cause of the glacial/interglacial cycles.
The theoretical extent of these ice sheets during the ice age 1.5 mya is shown in white on the map below. (White area = maximum glacial extent 1.5 million years ago in the Pleistocene Epoch - Microsoft Encarta) Ice ages are said to have occurred every 150 million years, and last for at least 1 million years. According to the ice age theory, our current warm period will end with the beginning of another cold phase in 23,000 years time. Geologists claim that there have been 5 major ice ages. During ice ages the boundary of the ice sheet is hypothesised to spread and contract in cycles.