Some years ago, in preparation for a college semester in Costa Rica, I secured a copy of John Lofty Wiseman’s “SAS Survival Handbook.” After assembling a survival kit inside an Altoids tin, I studied how to evade a volcanic gas ball or trap a monkey. Should I be forced to ditch my plane in the Gulf of Mexico, I felt confident that I could obtain freshwater by sucking on fish eyes.

Such skills, however, may be practical only if fish remain in the oceans and monkeys in the trees. MacGyvers in the 21st century — or the 31st for that matter — will face a suite of existential challenges that cannot be remedied with nylon fishing line. A warmer Earth could unleash continent-wide droughts and wars over water supplies. Or a new plague could sweep through our cities and kill millions. Or else an asteroid could slam into Pittsburgh, sparking fires that transform the landscape into charcoal.

Although these doomsday scenarios may sound like fantasy, only the solutions to them are. In “Scatter, Adapt, and Remember,” Annalee Newitz presents a sort of prophylaxis for the apocalypse. As the founding editor of io9, a Gawker Media blog about science and futurism, Newitz is a techno-optimist, convinced that we humans can outwit just about everything our solar system throws at us in the coming millennia. “How can I say that with so much certainty?” she asks. “Because the world has been almost completely destroyed at least half a dozen times already in Earth’s 4.5-billion-year history, and every single time there have been survivors.” She’s probably right.

The worst extinction in Earth’s history, the Great Dying, took place 250 million years ago — long before humans were around — when a massive volcano spewed particles into the air, blocking the sun and triggering a brief but catastrophic ice age. About 95 percent of species were wiped out, turning the oceans into a bacterial sludge that scientistis have nicknamed Slime World. A few larger animals did survive, including half a dozen species of “shovel lizard,” a pig-size beast known as Lystrosaurus. One of their secrets seems to be that they burrowed underground so that they wouldn’t be cooked by the first fiery blasts.

Newitz returns to this idea of subterranean refuges later in the book. She tours the Cappadocia region in Turkey, where starting in the 5th century, people carved underground cities in volcanic tuff. One site, Derinkuyu, descends five levels to a depth of 180 feet and is complete with feeding troughs for livestock carved into the walls. Historians believe that such cities could have protected their citizens from raids, but they are also a model of how we can survive long-term in the event of a nuclear blast.

‘Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction’ by Annalee Newitz (Doubleday)

The most engaging sections of the book come when it veers into Cormac McCarthy territory, sketching out scenarios in which the dregs of humanity must recolonize the Earth’s surface. If we’re lucky, the hangers-on will have access to a repository of human knowledge called the CD3WD database — possibly preserved in a survival kit as “a thick sheaf of papers” — containing instructions on building a water pump, preserving yams and treating diarrhea in sheep. At the same time, our present-day efforts at sustainability and social justice may help prolong our species’ reign. Our urban gardens may be part of the resilient, living cities of tomorrow. Synthetic microbes can fill cracks in our bridges, and a global health surveillance network will catch epidemics in the developing world before they spread.

But as Newitz ventures further into this speculative future, describing a technologically augmented world where our brains are uploaded onto computers and humans with artificial lungs bounce around one of Saturn’s moons, she seems more caught up with the hows of species survival than the whys. “Eventually we’ll have to move beyond patrolling our planetary backyard and start laying the foundations for a true interplanetary civilization,” Newitz writes with apparent conviction. “The long-term goal for homo sapiens as a species right now should be to survive for at least another million years.”

Here is where Newitz and other techno-optimists lose me. Adrift on the open sea, each of us will undoubtedly pull herself to safety aboard a life raft. We have an ethical obligation to help others do the same and to reduce suffering in the world. But the virtues of preserving our species and conquering distant moons are far more dubious. Some may find comfort in the idea that our species’ DNA will survive for eternity in this icy universe, but as far as I can tell, staving off extinction is more about vanity than morality. It is the romantic hope that we are heading toward something larger than each of our singular lives and that some similar being will one day admire the tweets we wrote and the asphalt we poured. Homo sapiens

For her part, Newitz would like her “post-Homo sapiens offspring” to “remember us as brave creatures who never stopped exploring.” It’s a nice sentiment. My guess is they’d prefer it if we just found a good way to turn our bodies into biofuel.

Brendan Borrell is an Alicia Patterson fellow and writes about science and the environment for Bloomberg Businessweek, Scientific American, Smithsonian and many other publications.


How Humans Will Survive

a Mass Extinction

By Annalee Newitz

Doubleday. 305 pp. $26.95