"What does that mean, besides lower carbon?"

It also means fresh air in the cities and much less noise.

Not a small point.

Smaller points would be less enviroment damage with oil drills, potential groundwater poisening or earthquakes with fracking, not oil tanker crashes and oceanic catastrophic events.

And about Saudia Arabia: I don't see, why "we" need to have a plan for them.

I see less money for various fanatic groups, if the arabic oil nations have to be a bit more conservative about money spending.

But what they could do (and some people there see this, too) is invest heavily in solarenergy, too and basically do solarfarming. And then use that energy to produce big time, or directly export the energy. Processed in form of hydrogen/methanol/.. or with high voltage direct current transmissiom directly to europe for example.