After Sustainability is a frightening book. Not only because it is based on the premise that climate change poses an apocalyptic future, but for the attitude that its author, John Foster, takes to that future. Foster is of the mind that we have passed the point of no return and that nothing that we can do as a society will significantly mitigate the harms that a changing climate will create. He is dismissive of environmentalist and activists that suggest we might achieve some kind of sustainable, low carbon, global society that will be remotely livable. Hence, "after sustainability" essentially suggests how we should think about our future once we have given up the false hope of sustainability.
His prescription calls for embracing our "dark self" which seems to be primarily committed to "existential resilience." At times, Foster appears to suggest that this is a welcome return to a pre-moral attitude that is an expression of our primitive animality. Less philosophically, Foster appears to suggest that societies that are rich enough should prepare to erect barriers to immigration from less fortunate societies and defend those barriers at all costs. Whether he is or is not advocating this, he certainly seems to suggest that this will be a consequence of the apocalypse of climate change and that those who will survive will be those who are able to create something akin to the "transition towns" recently created to prepare for the economic disruptions following peak oil.
In all, Foster's attitude is needlessly pessimistic and assumes the coming of worst-case scenarios for climate change. His response is quite in line with the amoral attitudes of American survivalists. A more grounded assessment of our situation would indicate that there is a high chance, perhaps even likelihood, that we will not be able to preserve a functioning global society and that the repercussions of this will be disastrous for most of the world's population; however, there is also a non-negligible chance that what we do today will significantly mitigate the damage that climate change might otherwise do. The worst-case scenarios result from "business as usual" characterizing the world's energy future and there indeed are power forces that will seek to continue with business as usual; however, just as the physics of the planet might be subject to dangerous tipping points, so too are our political, social, and economic institutions subject to tipping points. Indeed these institutions might be far more subject to tipping points. Abandoning the pressure to mitigate changes in our climate (as Foster seems to recommend) surrenders any chance that we might reach those positive tipping points. If Foster is right, then nothing we do will avoid an apocalyptic future, but abandoning our moral responsibilities in favor of self-preservation based on his pessimistic assessment is premature and certainly morally indecent.