Global Catastrophes: A Very Short Introduction

A sample of what's in store for us humans...:
Many take unceasing infinite progress for granted. After all, hasn't humanity survived and gradually bettered its place on earth for the last 4,000 years? Though this remains arguably true, "civilization", as we call it, in geologic time has barely breached the infantile stage. A mere 4,000 years means practically nothing to the powerful forces that shape our living space. The miniscule 1k or less human brain strains inexorably to fathom a span of 4 billion or even 1.2 million years. But what it can see from this height reveals a race of doily fragility. A race that often gets beaten and pummeled by the very rock that gives it its life. In other words, the earth and the universe have given us some pretty good whoopings in the past. And there's plenty of evidence that more await us on the horizon. This small book delivers a great introduction to just what could lie in store. Its original title, "The End of the World: A Very Short Introduction", probably smacked a little too much of despair. The change made sense, because this book does not spew misery and hopelessness. It actually states that our race will very likely survive numerous nasty fulminations (though admittedly in greatly decreased numbers), because we've survived them in the past. Still, the threat of human extinction always looms to some degree. Four chapters (with accompanying "facts to fret over") focus on four naturally-induced disasters: global warming, global cooling, internal disruptions, and asteroid strikes. But preceding this, an introductory chapter on the workings and origins of the earth jump starts the discussion. Those with no background in geology or cosmology will learn much, such as the formation of the earth from accretion disks and the foundation of plate techtonics. The earth began as a nasty place where no known life could have survived. Eventually things cooled down, but bits of the nastiness remained. And we continue to deal with these today in the form of natural disasters. Anyone who wants to know just how complex the debate over global warming can get should read chapter 2. The author starts with the premise that humans unarguably do contribute to global warming and that the majority of scientists agree on this. He presents a litany of evidence for this, and then lists the consequences: rising sea levels, droughts, more intense storms, more El Ni?o events, falling water supplies, and even cooling. Some evidence exists that suggests rising global temperatures may hasten the onset of the next Ice Age (discussed in chapter 3). So, paradoxically, warming might lead to cooling. A "little ice age" occurred between the thirteenth and nineteenth centuries, exposing some of the natural cycles the earth goes through. Then "the year without a summer" occurred in 1816 (probably brought on by a large volcanic eruption). So the author does not deny that the earth's temperature fluctuates throughout time, but he does claim that our "experiment" with excessive industrially produced carbon dioxide emissions "messes with" the entire system. This "messing" has led to higher and higher temperatures over the last two hundred years. And if we don't stop, things will just get worse. Chapter 4 takes on "the enemy within", or volcanoes, earthquakes, and tsunamis. Volcanoes play a vital role in the earth's continuing formation, but they can also cause massive loss of life. Though volcanic activity takes place frequently, super eruptions thankfully remain very rare. Using the logarithmic VEI (Volcanic Explosivity Index) scale, the author compares relatively minor eruptions (with VEIs between 0 and 2) to superblasts that cause devastation (VEIs 3 and up). The last VEI 7 eruption occurred in 1815 (in Sumbawa, Indonesia). And a very dangerous VEI 8 blast happened 74,000 years ago at Toba in Sumatra (now a lake). Some think that this blast may have come close to obliterating the human race. Also, deadly VEI 8s have occurred at the present location of Yellowstone National Park a million or so years ago. These pretty much wiped out most everything on the North American continent. No one really knows if Toba or Yellowstone might fulminate again. Just as disturbing, a large mass of earth at Cumbre Vieja (in the Canary Islands) sits waiting to collapse and bring on mammoth tsunamis. But when? Plus, earthquakes in heavily populated areas (the author tells the grisly tale of the 1923 Tokyo-Yokohama earthquakes) continue to threaten millions of lives. And 2004's hugely destructive Indian Ocean tsunami (brought on by deep ocean earthquakes) told us all how much destruction large waves can deliver. The final chapter brings up a now familiar doomsday scenario: the end of the world via asteriod or comet impact. Around 1000 near earth asteriods (NEAs) exist, but scientists have not yet identified them all. But do these objects hit the earth only periodically or do they come in waves? Either way, examples such as Chicxulub (now thought to have obliterated the dinosaurs), Tunguska, and Meteor Crater speak for themselves: The right impact in the right place would unleash horrific destruction. Not only that, the dust kicked up by such an impact could block out the sun for years or decades. Luckily these only seem to occur once in a great while (on the order of millions of year cycles). Such is the world and universe that we live in. It's dangerous. Nonetheless, people have pulled through terrible unimaginable catastrophes in the past. And in spite of these we still inhabit this place. But more will undoubtedly arrive in one form or another. Not only that, human life on planet earth will inevitably come to an end. In about 5 billion years the sun will supernova. We'd best not stick around for that. Though some may find the contents of this book depressing and deflating, it nonetheless conveys essential knowledge for long-term human survival on this planet. After all, the more we know about the potential pitfalls the more we can avoid or mitigate them. Shutting one's eyes to the harsh realities will only worsen the situation and foster illusions of guaranteed infinitude and invincibility. Conversely, opening one's eyes may inspire well-directed action. This book provides a great introduction for anyone to the topic of natural global disasters. The reading level stays accessible throughout and the content may end up changing the way readers think about their place in the world.

Concise, hard-hitting and compelling - a brilliant introduction:
The Very Short Introduction series by Oxford University Press has a good reputation for presenting challenging subjects in an easily accessible manner. "Global Catastrophes" by Bill McGuire is one of its very best examples. Originally published in 2002 as "A Guide to the End of the World", it has since been updated to include events as recent as 2005, with a new preface as well as a fully revised text and bibliography. The book deals exclusively with environmental phenomena rather than man-made, technological disasters. In each chapter McGuire explores the evidence for - as well as the likely effects of - of different catastrophes that could, in the near future, put an end to human civilisation, namely global warming, a new ice age, supervolanoes and other tectonic hazards, and lastly asteroidal impact. His mastery of the material is clear, and at every stage he is careful to back up his arguments with facts and figures drawn from scientific studies and computer models. At the same time his style is conversational and makes on the whole for easy reading, although occasionally the analogies he chooses tend to confuse rather than illuminate. The opening chapter on global warming is the book's tour de force - as well as probably the most relevant for the reader today - providing a succinct summary of the main issues and sources of contention. McGuire pulls no punches, making it clear just how unprecedented is the effect that human industrial activity is having on the global climate, and how our planet is hotter now than it has been for 90% of its history. For any sceptics of climate change, or of its future implications for our civilisation, this will be a potent wake-up call. In complete contrast, the next chapter explores the counter-intuitive (yet nevertheless scientifically plausible) theory that rising global temperatures could in fact trigger a rapid freeze and a return to Ice Age conditions. But regardless of whether we are set for global warming or global cooling, McGuire demonstrates why this is an especially bad period in geological time for us to be experimenting with our atmosphere and climate. The third chapter - on supervolcanoes and other tectonic events - is similarly well-argued, as one might expect from a Professor of Vulcanology at University College London. One disappointment, however, is the short treatment afforded to the topic of flood basalt eruptions, in particular the Deccan Trap event, which is now thought to have been a contributing factor in the decline and extinction of the dinosaurs. A significant amount of research is now being conducted into these events, which could have been explored further. Finally, McGuire's discussion of potential extinction-level asteroidal impact is both balanced and considered, stressing the catastrophic effect this would have while also underlining the unlikelihood of such an event occurring in the near future. The book includes 20 images and diagrams, serving to illustrate and reinforce McGuire's points, as well as 2 appendices, summarising the relative frequency of the various threats and plotting the most significant on a geological timescale. The bibliography is thorough, divided according to the relevant chapters, and runs to no less than 65 titles, making this book an excellent platform for exploring the subject further. All in all, "Global Catastrophes: A Very Short Introduction" is an excellent overview of what is a difficult, unsettling and sometimes contentious subject, and a book that I can highly recommend.