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.
An ice age is a period in Earth's history when the ice on the polar caps significantly expanded due to an overall lowering of the Earth's global temperatures. During these periods land in North America and Northern Europe were covered by giant ice fields and glaciers.