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.
Although the exact causes for ice ages, and the glacial cycles within them, have not been proven, they are most likely the result of a complicated dynamic interaction between such things as solar output, distance of the Earth from the sun, position and height of the continents, ocean circulation, and the composition of the atmosphere.