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An urgent tour of catastrophic risks calls for action

End Times: A Brief Guide to the End of the World

Bryan Walsh
Hachette Books
414 pp.
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Extreme global catastrophe is a subject of endless fascination, and many books have been written on it. Those written by journalists for general audiences are often narrowly focused on the science of various apocalyptic scenarios (1, 2), whereas books by academics often also cover ethics and policy issues and emphasize the authors’ analysis over interviews and narratives (3–5). End Times by Bryan Walsh offers a bit of both approaches, presenting interviews and narratives across the range of science, ethics, and policy issues on catastrophic risk. The result is a highly readable account of the field of global catastrophic risk as it is currently constituted.

The book opens with the commonly articulated moral argument for focusing on extreme catastrophes, rooted in a concern for future generations. Unfortunately, Walsh’s emphasis on catastrophes that could result in human extinction gives short shrift to alternative scenarios in which a small number of survivors never fully rebuild (6).

The core of the book features chapters covering specific risks: Earth-asteroid collision, volcano eruption, nuclear war, global warming, disease outbreaks, biotechnology, and various threats from artificial and extraterrestrial intelligence. Walsh speaks the most authoritatively on global warming and naturally occurring pathogens, having covered both in great detail over his career with Time magazine. Nonetheless, each of the risks gets a sound treatment, informed by interviews with some of the top experts in the field.

The book is rich with compelling insights and stories. The reader learns of asteroid collisions that could be mistaken for nuclear attacks, archaeological digs that offer insight into the human death tolls of ancient volcanic eruptions, and the emotional and psychological difficulty of evaluating mass fatalities. Walsh delves into the inertia of global energy systems, the trade-off between a pathogen’s lethality and its ability to spread, the challenge of governing emerging technologies, and the heated debate over whether we should send messages to extraterrestrial civilizations.

In the book’s first chapter, Walsh tells the story of comet Shoemaker-Levy 9, which was discovered on 24 March 1993, about a year before its collision with Jupiter. The collision garnered wide attention and motivated policy attention to the threats posed by asteroids and comets. As the book explains, efforts to address the threat were already under way, but the collision made the threat more tangible. This shows how science and politics can combine to make progress, even for catastrophic risks that might seem far-fetched.

In chapter 3 (“Nuclear: The final curtain on mankind”), Walsh interviews Alan Robock, a distinguished environmental scientist who has led research on the climatic effects of several catastrophe scenarios, including nuclear war. Robock confides, “I’m much more scared of nuclear war than I am of global warming because nuclear war can be instant climate change.” This is an important point: the rapid climatic change from nuclear war (known as nuclear winter) would be much more difficult for humans to adapt to than the more gradual warming of the planet from greenhouse gas emissions.

End Times is framed as a wake-up call for humanity to recognize the urgency of the risks and act accordingly. Will it succeed? Many previous books have presented similar moral and scientific arguments and have left little impact relative to the scope of the challenge posed by the risks.

This raises two questions that get too little attention in studies of catastrophic risk. First, what compels people to take major risks seriously? Walsh traces his own motivation to a “we all might die” epiphany he experienced while covering the 2003 SARS outbreak in Hong Kong but does not otherwise explore this topic. Second, what can be done to safeguard humanity when people are not motivated to heed warnings about existential threats? Except for the section on global warming, End Times gives scant attention to the fact that most people do not experience a future-oriented moral perspective when it comes to catastrophic risk.

It is nonetheless easy to recommend End Times. The topic is important (arguably, exceedingly important), Walsh’s treatment of it is sound, and his writing is clear and engaging. Among the crowded collection of books on threats to humanity, End Times offers an excellent general-purpose introduction. It is a worthy choice for people from all backgrounds seeking to understand the state of affairs on major threats to humanity.

About the author

The reviewer is at the Global Catastrophic Risk Institute, Washington, DC 20016, USA.