Are you talking about techies or rich entrepreneurs? These are quite different groups of people. I work/talk to many well known techies, and none of them have libertarian tendencies; quite the opposite sans the occasional non-libertarian conservative.

Emission from a jet is significant, but gets diluted over a wider range. The problem with pollution is mainly concentration and failure to disperse, and become absorbed (carbon dioxide and other pollutants occur naturally, but concentrations of them are a big problem, especially when inversions occur).

Those kids at Berkeley would probably never have worked at Google MV if they couldn't live in the city.