I see two big limiting factors that we are giong to have to save oil for - The aforementioned aviation, and all the products that we derive from oil.
Looking at the various sectors I predict:
Cars -Trend to electric, but maybe also biofuels. We know that corn ethanol is energy negative, but I remember reading some research that cellulosic or algae derived ethanol may eventually be net energy positive. The only restriction then becomes space to grow the feedstocks.
Trucking - I think we have to move as much shipping as possible to rail.Then what trucking is left maybe run on biodiesel? Less trucks also helps with traffic and road wear&tear;.
Rail - Electirc. And a LOT more of it.
Aviation - Has to keep relying on oil, or expensive synthetics made via Fischer Tropp. We really need to stretch oil out to keep this sector alive.
Home heating - getting everybody on wood would be nice but then we will run out of trees
So the trend will eventually go electric there too.
Electric supply - Here is the million dollar question!
hydo is aobut maxed out.
Wind and solar are good options but we have to:
1 - prove the lifespan is long enough that they produce more energy than used in build out
2 - find economical ways to store the power produced. You cant match generation instantaneously to demand like with fossils. (ie. how do you get electricity at night from a soalr cell?)
Nuclear fission is going to have to get ramped up big time but again you face the problems of:
1 - long lead time to build new reactors
2 - what to do with waste?
3 - If you built enough nuclear to power the whole planet we might run out of uranium. Nobody wants to do the alternative and build breeder reactors that make weaponizable plutonium....
A breakthrough in nuclear fusion would save the day but that has been 50 years away for 50 years now.
And then all the other products that are made from oil and natural gas - fertilizers, pesticides, ashphalt, plastics, etc.
I know there are bio-plastics, but I'm not to familiar with alternatives for all the other oil based products. The best bet might be to eliminate oil from energy uses early and save it for these uses. .
-Jeremy