If the end of the world is something that keeps you up at night you might want to skip this book. Some might snigger at the “rogue robots” in the book’s subtitle, but End Times is a serious look at so-called existential risks. Former foreign correspondent, reporter, and editor with TIME magazine Bryan Walsh takes an unflinching look at the various disasters that could wipe out humanity, the people whose jobs it is to seriously think through catastrophic threats, and how, if at all, we can prepare ourselves.

End Times: A Brief Guide to the End of the World, written by Bryan Walsh, published by Hachette Books in August 2019 (hardback, 406 pages)

Surveying the table of contents feels like the roll call of Doomsday classroom: “Asteroid impact? Here. Volcanic eruptions? Check. Nuclear war? Thanks, your usual radiant self, I see. Climate change? Stewing in the corner over there. Pandemic and biotechnological killer virus? Thanks – please stop trying to poke each other’s eyes out. AI overlord? Check, can you please put down your smartphone? Aliens? Has anyone seen the aliens?”

Several of these topics have been the subject of book reviews here before. Walsh starts with the asteroid impact that killed the dinosaurs before turning his attention to the search for near-earth objects, covering similar ground to the recently reviewed Fire in the Sky, including the Shoemaker-Levy 9 comet, a visit to the same Catalina Sky Survey, and an interview with NASA’s Planetary Defense Officer Lindley Johnson. The chapter on volcanism covers the usual suspects, such as the Siberian Traps, the Toba volcano, the Tambora volcano, and the looming threat of the Yellowstone supervolcano.

“Surveying the table of contents feels like the roll call of Doomsday classroom.”

The threat of nuclear war is a topic that I am less familiar with, and Walsh walks you through the history of the first atomic bomb tests, the arms race during the Cold War followed by disarmament, and the recent resurgence in nuclear weapons stockpiling. Combined with the secret government war plans and the many near-misses, this makes for chilling reading.

Walsh has interviewed plenty of people while researching this book. Additionally, he draws on personal experience when writing of climate change and pandemics. He was stationed in Hong Kong during the 2003 outbreak of SARS and makes many relevant observations: vaccine resistance, the lack of investment in developing new ones, and the evolutionary trade-off between transmissibility and fatality that prevents diseases from completely wiping out their hosts.

“[Vaclav] Smil’s point about the difference in energy density between fossil fuels and renewables […] is often overlooked”

Just as Jon Gertner, he has visited Greenland’s Jakobshavn glacier (see the previous review of The Ice at the End of the World). He discusses climate change tipping points, the fiendish problem of continued global warming even if we stopped emissions now, why addressing the hole in the ozone layer was easy and curbing carbon dioxide emissions is not, and why we all need to read Vaclav Smil’s work. Smil’s point about the difference in energy density between fossil fuels and renewables, and the challenges this presents, is often overlooked.

Walsh attended the 2009 UN climate change summit in Copenhagen and it is here that he makes some of his sharpest observations on the psychology of our inaction. He notes how in Copenhagen: “no one really wanted to do all that much to slow climate change. Not if it carried any political or economic risk. Not if it could cost them their job, or restrict their citizens in almost any way. Climate change was important, sure – but not that important” (p. 137). He calls climate change “the ultimate collective action problem” and highlights how this existential threat, uniquely, foremost affects generations yet to come.

“[Walsh] calls climate change “the ultimate collective action problem”.”

The remaining threats – biotechnology, artificial intelligence, and aliens – all stand apart as ones that have yet to pass. He considers biotechnology becoming bioterrorism in the wrong hands the biggest threat of all, discussing at length the ethics, regulation, and double-edged nature of this kind of scientific research. He clarifies why there is nothing to giggle about “killer robots” if so-called artificial general intelligence were to enter the loop of recursive self-improvement and take off on an exponential curve. And the seemingly unlikely threat of alien life forms results in a chapter that nicely discusses the Drake equation, the Search for Extraterrestrial Intelligence, and some of the solutions to the Fermi Paradox (see also these two fantastic YouTube videos from Kurzgesagt).

As a reporter, Walsh knows how to write a captivating and entertaining book, even if the topic is grim. Yet I do have some concerns. I appreciate that, in tackling so many big subjects in just over 300 pages, the coverage is going to be somewhat superficial. Although he refers to peer-reviewed literature, I also noticed many references to online newspaper and magazine articles. Similarly, he seems to cite some, but not all, personal communications with people. And when mentioning the work of certain authors (e.g. Vaclav Smil), he curiously cites articles about them, rather than anything they have written.

“there is nothing to giggle about “killer robots” if so-called artificial general intelligence were to enter the loop of recursive self-improvement”

If it seems I am harping on about this, I ended up questioning how much Walsh has relied on second-hand information for this book. Although I trust that as a reporter he can judge sources for their reliability, I worry that he sometimes misses out on subtleties. A point in case is the extinction of the dinosaurs, where he sketches as dissenters those who blame massive volcanic eruptions. Although the evidence for impact is by now undeniable, the relative importance of each remains hotly debated (recent examples of palaeontologists airing different views in their books are The Rise and Fall of the Dinosaurs and The Dinosaurs Rediscovered). And the idea of a global conflagration following impact is not supported by research on fossil charcoal. Similarly, the fear of AI running rampant has its share of dissenters.

Finally, I am not sure I always share Walsh’s optimism that e.g. geoengineering will offer a solution to climate change, or that colonisation of space is the answer to an overcrowded planet. I would not want to exclude these, but I feel as much attracted to Eileen Crist’s call of scaling down and pulling back. Which brings me to two existential threats I felt were missing. What of the one-two punch of habitat destruction and rampant resource extraction? Together with climate change, they are, in my opinion, symptoms of overpopulation accompanied by increasingly widespread overconsumption. I expect these will cause global disruption before climate change can get to us.

“What of […] habitat destruction and rampant resource extraction? […] I expect these will cause global disruption before climate change can get to us.”

If a book such as Global Catastrophic Risks seems too daunting at first, End Times makes a great read as a popular introduction to existential threats. Where it concerns ethics and philosophy, or human psychology in the face of threats, Walsh makes some excellent observations. Keeping in mind above reservations, I would encourage readers to subsequently go deeper into the literature if any one of these topics fascinates them, or consider the recent book The Precipice which has similar but more in-depth coverage.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

End Times paperback, hardback, ebook, audiobook or audio CD

Other recommended books mentioned in this review:

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

Can you have too many books on the same topic? Not four months after the publication of Cosmic Impact in February 2019, which I reviewed earlier this year, Scribner books published Fire in the Sky in June. The former book was written by astrophysicist Andrew May, while Gordon L. Dillow is a newspaper reporter and war correspondent, coming at the subject from a different angle. Despite touching on many of the same events and topics, he provides a wealth of new information in what is a thoroughly researched work of popular science. But first, let’s go to Arizona and turn back our clocks some 50,000 years.

Fire in the Sky: Cosmic Collisions, Killer Asteroids, and the Race to Defend Earth, written by Gordon L. Dillow, published by Scribner Books in June 2019 (hardback, 277 pages)

As an Arizona resident, it is only logical that Dillow takes Meteor Crater as his starting point. At some 170 metres deep and almost 1200 metres in diameter this impressive astrobleme, or star wound (what a beautiful word he introduces here!), is one of the best-preserved impact sites on our planet. It also plays a large role in the history of impact theory and Dillow skillfully uses it as his jumping-off point for a science history lesson that spins itself out over the first half of the book.

Although Native Americans in the area believed Coon Mountain, as it was known back then, to be an impact structure, the Western academic establishment did not. They were still held in thrall by the geological doctrine of uniformitarianism, which held that changes on Earth happened gradually through known processes. When the famous geologist Grove Karl Gilbert mounted an expedition to Coon Mountain in 1891 to address the question of its nature, he considered the possibility of meteoric impact but rejected it in favour of a volcanic steam explosion. Not that strange, with the 1883 volcanic eruption of Krakatau still fresh in people’s minds. With that, the case was closed for geologists. But it was not for Daniel Moreau Barringer. Nor, later, for Gene Shoemaker.

“[Barringer] made his fortune mining but then wasted it over the next few decades […] digging holes in the crater, obsessed with the idea that there had to be an enormous meteor buried there somewhere.”

Where May’s book focuses more on the technical side complete with diagrams – the celestial mechanics of asteroid orbits, the different types of asteroids – Dillow instead largely focuses on the human story of geology’s history. He gives a delightful introduction to early efforts, including the 1800s group calling themselves the Himmelspolizei or Celestial Police. But the focus is on the fascinating story of both Barringer and Shoemaker. The former made his fortune mining but then wasted it over the next few decades, from 1904 to 1929, digging holes in the crater, obsessed with the idea that there had to be an enormous meteor buried there somewhere. He published academic papers on the topic, but his belligerent attitude made him few friends. The latter, upon visiting the crater in the 1950s, thought it looked like those left by nuclear bomb tests, just bigger. He changed his career from geology to astronomy, joined NASA, and set up the first observatory to find and track asteroids that could pose a risk to Earth.

A recurrent theme in this book is the reticence of the geological establishment to accept the impact theory. Despite mounting evidence, volcanism remained the preferred explanation for craters both here and on the moon. Dillow traces the big change in attitude to two things. He gives an excellent brief history of the dust kicked up by the famous 1980 Alvarez et al. Science paper that proposed the Cretaceous ended with a bang. And while scientists were busy arguing, Shoemaker discovered an asteroid on a collision course with Jupiter, which it hit in 1994.

From here on outwards Dillow makes clear how the sniggering around the wacky concept of giant-rocks-from-space died down, with the 2013 Chelyabinsk meteor a disconcerting reminder that the threat is real. He describes the many initiatives to find and track Near-Earth Objects or NEOs, and joins astronomer Richard Kowalski at the Catalina Sky Survey to learn how asteroid sightings are shared and verified by avocational astronomers around the world.

“There are really only two options to deal with an incoming asteroid: nudging it or nuking it.”

Dillow takes the same historical approach when considering what, if anything, we could do. From the 1967 MIT student project, Project Icarus, that asked participants to come up with solutions, to NASA’s 2005 Deep Impact mission that hurled a heavy projectile at a comet, people have been considering all sorts of strategies. NASA now even has a Planetary Defense Coordination Office and Dillow interviews its officer, Lindley Johnson.

There are really only two options to deal with an incoming asteroid: nudging it or nuking it. Dillow briefly considers the slow-push methods that aim to change an asteroid’s course but spends most time on the idea of the kinetic impactor. Basically, the idea of launching a large object or nuclear warhead to blow up the incoming threat. The latter is, unsurprisingly, controversial, and Dillow examines the different opinions on the topic. For now, it might be our only realistic option though. Similarly insightful is his coverage of several “asteroid war games” conducted by NASA and FEMA (the Federal Emergency Management Agency). These are tabletop exercises to train government officials on how to respond when a natural disaster strikes. Obviously, these drills are somewhat different from the regular ones, both in the likely long lead time where we know an impact is imminent years in advance, and the limited capabilities we currently have to actually do something.

Fire in the Sky is an excellent example of an outsider digging into a topic, doing his homework, talking to experts, and becoming fascinated with the story he uncovers. With a reporter’s flair, he transmits his enthusiasm, making this a fun book that treads lightly on the science side of things. His focus on the human history ensures the book does not simply rehash recent publications such as Cosmic Impact. Dillow makes a convincing case that, despite so many other problems here on Earth requiring our attention, we would do well to apportion some of our funds to keeping an eye on the sky.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Fire in the Sky paperback, hardback, ebook, audiobook or audio CD

Other recommended books mentioned in this review:

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

“Cosmic Impact: Understanding the Threat to Earth from Asteroids and Comets”, written by Andrew May, published by Icon Books in February 2019 (paperback, 167 pages)

The story of the extinction of the dinosaurs and its link to the Chixculub impactor has featured repeatedly on this blog. Walter Alvarez told the story in his own words in T. rex and the Crater of Doom, and it featured as one of the big five mass extinctions in Brannen’s The Ends of the World: Volcanic Apocalypses, Lethal Oceans and Our Quest to Understand Earth’s Past Mass Extinctions, while any dinosaur book worth its salt features the topic (see e.g. my reviews of The Rise and Fall of the Dinosaurs: The Untold Story of a Lost World and The Dinosaurs Rediscovered: How a Scientific Revolution is Rewriting History). Now, if someone could please show the dinosaurs the door, because there is far more to the topic than them, or the bad science shown in disaster movies such as Deep Impact and Armageddon.

May starts off with a short history of comets and asteroids. It obviously took a while before shooting stars were recognised for what they were: not bad omens, but hunks of space junk. Even so, the possibility of cosmic impacts was long dismissed. Although May doesn’t mention him by name, it was Scottish geologist Charles Lyell’s doctrine of uniformitarianism (May instead calls it gradualism in this book) that long held sway and pretty much ruled out (cosmic) catastrophes. The pseudoscience espoused in the 1950s by psychologist Immanuel Velikovsky (see The Pseudoscience Wars: Immanuel Velikovsky and the Birth of the Modern Fringe) also did not help its credibility. But, as documented at length elsewhere, it eventually became an accepted idea (see my reviews of Four Revolutions in the Earth Sciences: From Heresy to Truth and Cataclysms: A New Geology for the Twenty-First Century).

“Now, if someone could please show the dinosaurs the door, because there is far more to the topic than them […]”

So, we have dealt with the dinosaurs, and we have the idea on the table as something to be taken seriously. But before May can start talking about the threat to human civilization and what, if anything, can be done to avert it, there is a whole lot of astronomy to be dealt with first.

This is where I feel the book does an excellent job introducing the basic science, although he does seem to falter right at the start in explaining the differences between meteors, asteroids, and comets. Clear-cut definitions have been formulated elsewhere, but May instead focuses on the caveats, pointing out that these names were coined before people really understood what they were talking about. Furthermore, the more we study them, the more their properties seem to overlap. That’s all fair enough, but after a few pages I still was not quite clear on the difference between asteroids and comets.

“It obviously took a while before shooting stars were recognised for what they were: not bad omens, but hunks of space junk.”

Luckily, the more complex topics of the all-important orbits (which determine whether they will cross Earth’s path), the underlying celestial mechanics, and its terminology are all lucidly explained, including helpful diagrams. May briefly covers the different sources for all these rocks (the nearby asteroid belt, the more distant Kuiper belt, and the still more distant and hypothetical Oort Cloud) and the likelihood of impact. He is quick to inject a healthy dose of realism and sobering numbers here, because even the asteroid belt is, in reality, not particularly densely packed with debris. No matter how Star Wars depicted it, the Millenium Falcon could easily coast through this with the crew snoozing and no one would be the worse for wear.

But impacts do happen. Just look at the moon, May says. Although Meteor Crater in Arizona was long recognised as the only clear crater on the face of the Earth, many others have now been found. Coverage of this topic would not be complete without mention of the 1908 Tunguska Event in Siberia (see also The Tunguska Mystery, although May thinks there little mystery left here), the 2013 Chelyabinsk meteor, or the 1994 impact of the Shoemaker-Levy 9 comet on Jupiter (see The Great Comet Crash: The Collision of Comet Shoemaker-Levy 9 and Jupiter).

“No matter how Star Wars depicted it, the Millenium Falcon could easily coast through [the asteroid belt] with the crew snoozing and no one would be the worse for wear”

Now that cosmic impact is a topic that can be brought up again in polite company, new wild ideas have been quick to follow. May gives a quick and appropriately sceptical overview of the revival of the idea of panspermia (comets seeding planets with life), epidemics-from-space, the alleged periodicity of mass extinctions and its link to cosmic phenomena (see the latter part of Cataclysms but especially Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe), or the idea of a dark star companion to our sun (see The Nemesis Affair: A Story of the Death of Dinosaurs and the Ways of Science).

But, to repeat, impacts do happen, and May briefs the reader on NASA’s efforts at monitoring so-called near-earth objects, and the fantastic missions that landed on asteroids. Finally, he seriously considers the various options we have to defend ourselves from incoming asteroids and comets (blow them up, deflect them, redirect their course?).

“Especially the topic of planetary defence has tickled the imagination […]”

Especially the topic of planetary defence has tickled the imagination with a host of books on it in recent years, such as Near-Earth Objects: Finding Them Before They Find Us and The Asteroid Threat: Defending Our Planet from Deadly Near-Earth Objects. And Cosmic Impact is not the final word on the topic, see also my review of Fire in the Sky: Cosmic Collisions, Killer Asteroids, and the Race to Defend Earth.

Of all these, May’s book is the least expensive. At 155 pages his coverage of topics is well-balanced, though necessarily cursory in places. Given the brief of the Hot Science series this book is part of, that is only to be expected though. What it does deliver is a fast-paced and very readable book that avoids hype and is cautiously sceptical where it needs to be. A book that is sure to whet the appetite.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Cosmic Impact paperback or ebook

Other recommended books mentioned in this review:

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________