The International Energy Association already quietly admitted that the world reached conventional petroleum production in the middle of the last decade, which means at present we are either at a plateau or starting the long descent downward where production will decrease no matter how many more wells are drilled.
This basically means energy will no longer be abundant and the cost of it will increase. Unless some miracle technology is produced, industrial civilization will over time come to an end and we will more or less return to pre-industrial conditions. No more commercial aviation, private automobiles, mass production or industrial food production.
One thinker I appreciate a lot is Michael Greer. His ideas can be summarized like this:
My take is that modern industrial civilization is on the downslope of its history, headed for the compost heap of fallen empires alongside all the dead civilizations of the past. Peak oil and the other elements of the crisis of the contemporary world, in this analysis, are simply the current manifestations of patterns that shaped the fall of other civilizations, and our future will most likely follow a similar course – an extended, uneven decline extending over more than a century, including repeated periods of crisis followed by partial recoveries, ending in a dark age in which much of the technology, knowledge base, and cultural heritage of today will survive in fragments or be completely lost.
Now let's just assume this is the destiny of our modern civilization.
What's in store for Buddhism? This is what I'd like to discuss here.
To begin with, it means that Buddhism across the planet will have to endure severe economic contraction and potentially all the wars and social turmoil that come with it. Totalitarian governments with an anti-religion agenda are not unheard of even in recent memory. On the other hand, Buddhism will be able to provide spiritual security and a means of mental endurance during the coming hard times. There already is in the western world a return to religion, though not without a lot of opposition. The failure of modernity to provide what it promised has plenty of people disappointed and seeking something other than consumerism to satisfy themselves mentally and intellectually.
The other thing I foresee happening is Tibet regaining its independence. The fuel cost of keeping garrisons in Tibet will prove too expensive for the PRC, and they will probably have to deal with a great deal of internal revolts as time goes on and the economic growth which keeps the regime in power is essentially undermined. It could be that the PRC simply walks out of Tibet leaving a few token troops and police officers, which could be on the receiving end of some revenge attacks. What this means for Buddhism in Tibet is another matter.
Unfortunately, as much as many present day Buddhist teachers speak of social progress and development, a lot of this might be reversed when the hard times press people back into conservative attitudes and less generous states of mind. The ideas presented in modern Chinese Buddhism of "bringing the Pure Land" here, i.e., working towards utopia, will prove infeasible given the circumstances. This will likely lead to a lot of disappointed devotees who had invested so much emotion into such visions, only to see a sharp downward turn. The long discussions on a "Modern Buddhism" might prove to have been relevant only for a few decades really. The social arrangements to which such a project was adapted to will likely unravel.