&quot;we really cannot have 7 billion people drive cars&quot; ... I think we will have to... for a while.<p>Education is the best way of reducing population. Cars (or any type of personal transport) is crucial, moving the effort from humans to machines, leaving the human with more time and options. This leads to education and caring about the environment, politics etc.<p>So for a while we&#x27;ll have to have 7 billion people using cars (or at least that&#x27;s what the goal should be) then this will drop to 6 billion, then 5 then 4 etc.<p>We can power cars using solar. Terrestrial or orbital.