You can make plenty of cases for government-sponsored work leading directly to real income though. Military and space program R&D are areas that have produced a lot in this regard.
Even the oil majors are doing a lot of work on other energy sources, although their timelines for implementation are more realistic at 20-50 years rather than 5.
The government can also assist by tax advantaging work in some areas.
I don't think solutions will be either all public or all private, in any event.
