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.
And those small shifts in solar radiation were all it took to cause multiple ice ages during about the past 2.5 million years on Earth, which reach their extremes every 100,000 years or so.