The underlying assumption of this book is that fossil fuels cannot be effectively replaced, neither cost-effectively nor in the gross amount of available energy. And once the fossil fuels are gone, they are gone forever, meaning that industrial civilization as we know it will collapse--or more to be hoped, industrial society will experience a slow decline into what Greer calls "The Ecotechnic Future." Along the way there will be "scarcity industrialism" and a "salvage society." Some bad times will be had by almost everybody, and for some it will be horrific.
The idea that renewable energy sources won't measure up to what we are wantonly consuming today is not new, but it is sobering. (And we do need to sober up.) Robert U. Ayres and Edward H. Ayres make a more modest point in their book, Crossing the Energy Divide: Moving from Fossil Fuel Dependence to a Clean-Energy Future (2010). They argue persuasively that regardless of how much money the government and private enterprise put into the development of green alternatives, those sources of energy will not be developed fast enough. Their prescription is more efficient use of fossils fuels until the green revolution catches up.
Greer doesn't see any catching up. He writes that the world's annual energy consumption equals about one-fourth of the total solar energy absorbed by green plants annually with 86% of that coming from fossil fuels. (p. 247) Instead of energy conservation helping us to a sustainable future, he sees four "sweeping impacts on human life" to come. They are
(1) Depopulation. Quite simply, "the population bubble of the last few centuries is just as much a product of the exploitation of fossil fuels as the industrial age itself." And without fossil fuels to help grow and cheaply move food around the globe, "food surpluses that support toady's population levels will be impossible to maintain." (p. 39)
(2) Migration. People will move as they have done in the past from areas of relative poverty to areas of relative wealth, and the "wealth" will mainly be in food stuffs. Much of the world is already experiencing these migrations, Latin Americans into the US for example, Muslims into Europe; but in the future the migration directions may change and people from further away may land on more distant shores.
(3) Political and cultural disintegration. Greer does not dwell or make vividly scary what this can mean--but it would not be surprising to see that when things get scarce those with power will use that power to get what they want by any means necessary.
(4) Ecological change. Greer speaks of ecology a lot in this book, comparing the rise and fall of civilizations with the successions of natural ecologies from grasslands to climax forests.
What I think is most sobering (an apt usage worth repeating since we have been guzzling oil and are addicted to it) is Greer's point that "by the time actual shortages began, all existing resources would already be committed to meet existing needs." (p. 13) One of the consequences of this is that the transformation of our economies from fossil-based energy to renewal-based energy will be impossible to implement because the energy required for the transformation will be unavailable. It takes oil energy to build a nuclear power plant for example, and oil energy to build wind turbines and transport them.
Greer laments: "the fossil fuels that might have powered the transition to a sustainable future were wasted on a quarter century of extravagant living." (p. 13)
Some bon mots and sharp insights:
"...[G]overnment and business leaders in the world's industrial nations, which have even more to lose from the twilight of cheap abundant energy than their poorer neighbors, are still treating the twilight of the age of oil as a public relations problem." (p. 19)
"As it exists today, industrial society can best be described as a scheme for turning resources into pollution as fast as possible." (p. 28)
"...[F]rom the tumbrils of the French Revolution to the killing fields of Khmer Rouge Cambodia, it has always been those radical movements that promised heaven on earth that yield the closest approximation to hell." (p. 187)
"It's vanishingly rare for a society to collapse at the peak of its wealth and power, for the simple reason that wealth and power are two of the most effective means of staving off collapse." (p. 192) This suggests that the US is not yet in its dotage--although things might get a little rough for our grandchildren.
Central to Greer's argument is the idea that we will pass through successions such as a landscape passes from R-stage invasive plants like weeds to shrubs and bushes to K-stage plants like oaks and pines in ecological sequence, which typically ends in what ecologists call a climax forest. Greer emphasizes that "succession moves toward stability, not toward Utopia." (p. 240)
He sees history (and I would say that Greer is primarily a historian working here as a futurist) as an ecological phenomenon with "processes that appear across the range of ecosystems in the nonhuman world." The equivalents that in sees in history are (1) a rhythm in the rise and fall of civilizations; (2) the succession mentioned above "ending in the social equivalent of a climax community that remains stable until changes in the environment disrupt it; and (3) cultural evolution. (pp. 241-242)
As much as I admire Greer's erudition and insight I think the main strength of this book is in Greer's eminently readable prose. As Yogi Berra might have said, "prophecy is hard, especially about the future"; but Greer 's vision is one that I think is well worth paying attention to.