Since the first "oil shock" in the early 70s I have believed that the eventual solution to hydrocarbon requirements, such as for plastics, would be by providing "photo-synthetic front ends" to refineries, now referred to as bio-mass. Nitrogen fixation could eventually be provided by bacteria similar to those that fix nitrogen inside the roots of legumes. The balance of output products should change given the present awareness of the problems of global warming.

We at least could have the demonstrated technology to provide all of our ground transportation technology via electric vehicles with batteries and ultracapacitors, with a means for either quick recharge or "on the go" recharge from inductive pick-ups or alternative means. A political hurdle would be agreeing to standards to which manufacturers could build compliant vehicles. If you have ever been involved with a "standards committee" you will be familiar with the problem.

We could also greatly increase the speed and efficiency while decreasing the cost and polution of long distance transportation for both people and freight, possibly combining rights of way for both energy transmission and freight and personal transportation into a rebuilt  infrastructure.  In relative terms this should be less expensive and less technically challenging than the moon shot in the 60s.  The biggest obstacles are political.

"It is not necessary to have hope in order to persevere."