Martin Rees. On the Future: Prospects for Humanity. Princeton: Princeton University Press, revised edition., 2021. xviii + 256 pp. Paperback, $12.95.

• Author: Hare, J. Laurence

It is quite possible that the future may be more in vogue than it has been for a long time. It is a perennial concern, but a great number of new works have appeared lately, vacillating between doomsday predictions of climate disaster, as in The Uninhabitable Earth from journalist David Wallace-Wells, and upbeat hopes for meaningful change, as in Utopia for Realists, by the historian Rutger Bregman or in The Ministry for the Future, from science fiction maven Kim Stanley Robinson. Standing amidst these polarizing prognostications is British astrophysicist Martin Rees, whose latest in a long line of writings on the future, aptly titled On the Future: Prospects for Humanity, attempts a balanced perspective on the perils and promises of the years ahead. Originally published in 2018, Rees has updated the latest edition in 2021 with new reflections on the "global spasm" of COVID19 (p. vii). The pandemic raises the stakes for his overarching work while also supposedly validating his central argument that "Science and technology can... be our salvation" (p. xii). In some ways, Rees' book, though it roots itself in level-headed science, can come across as one of the most ambitious contemporary writings on the future, extending from tomorrow to the next millennium before ultimately circling back and reflecting on the very foundations of science itself.

In his early chapters, Rees starts small, focusing less on predictions and more on possibilities. He offers an inventory of threat assessments ranging from climate change and various forms of ecological disaster to the dangers of technology, including nuclear war, artificial intelligence, and cyber- and nanotechnologies. There are threats of imminent violence, of course, but also slower perils of dislocation, as in the impact of robotics on human labor or of medical breakthroughs on population growth. With such considerations, Rees makes clear that he is not a blind optimist, and it is difficult early on to find much cheer in his analysis. But later he stresses the relatively low risk of many of the technological catastrophes about which humans so often fret, and he reminds readers of the potential for technological solutions to mitigate others. If there is a common thread in his discussions, it is that the rarity of future catastrophes should not diminish the scale of the danger, and that human societies should develop resilience in the face of the worst-case scenario. "For the first time," he claims...