Monday, December 23, 2013

Apocalyptic Planet

Craig Childs is a nature writer and globetrotting adventure hog.  He’s been thinking a lot about apocalypse lately.  It’s hard not to.  The jungle drums are pounding out a growing stream of warnings — attention! — big trouble ahead.

The Christian currents in our culture encourage us to perceive time as being something like a drag strip.  At one end is the starting line (creation), and at the other end is the finish line (judgment day).  We’re speeding closer and closer to the end, which some perceive to be the final Game Over for everything everywhere.  Childs disagrees.  “We are not on a one-way trip to a brown and sandblasted planet.”

He was lucky to survive into adulthood still possessing an unfettered imagination, and he can zoom right over packs of snarling dogmas that disembowel most folks who attempt to think outside the box.  In his book Apocalyptic Planet, he gives readers a helpful primer on eco-catastrophe.  The bottom line is that Earth is constantly changing, and it’s not uncommon for change events to be sudden and catastrophic.

He purports that the big storm on the horizon today is not “The Apocalypse.”  It’s just one more turbulent era in a four billion year story.  Out of the pile of planetary disasters, he selects nine examples, travels to locations that illustrate each one, and then spins stories.  Each tale cuts back and forth between his adventures at the site, and background information from assorted sources.  It’s an apocalypse buffet.

Deserts are a quarter of all land, and many are growing now.  History tells us that they can expand and contract rapidly, taking out societies in the process.  Four out of ten people live in regions prone to drying up.  New Mexico once experienced a drought that lasted 1,000 years.  Beneath the driest regions of the Sahara, pollen samples indicate that the land was once tropical savannah and woodlands.  A few years ago, Atlanta, Georgia (not an arid region) came close to draining its water supply during a long drought.

Glaciers are melting at rate that alarms people who think.  Childs visited the Northern Patagonia Ice Field, where hunks the size of buildings were crashing down off the edge of the dying glacier.  Enormous volumes of melt water are raising the global sea level.  He also visited the Bering Sea, where the old land bridge is now 340 feet (103 m) underwater.  Beringia was once a broad treeless steppe, home to an amazing community of megafauna.  If climate change eliminates all ice, the seas could rise another 120 feet (36 m) or so, and major rivers will run dry from lack of melt water.  About 40 percent of humankind resides near coasts.  Nobody knows how fast the seas will rise, or how much.

The planet has been smacked countless times by asteroids.  Many believe that the dinosaur era was terminated by the Chicxubal impact on the Yucatan Peninsula.  There are many, many objects zooming around in space that could hit us, but Childs recommends that our time would be better spent worrying about catastrophic volcanic eruptions.  There are daily eruptions from 200 active volcanoes.  Extreme eruptions have loaded the atmosphere with dust, blocking out sunlight, leading to winters that lasted for years.  Humankind once had a close call with extinction when Mount Toba erupted 73,000 years ago.

Climate change is likely to affect the movement of the planet’s tectonic plates.  As glaciers melt and dam reservoirs evaporate, there will be less weight on the land below, allowing it to rise.  Tectonic shifts can lead to earthquakes, tsunamis, volcanic eruptions, and altered ocean currents and weather patterns.

All civilizations are temporary outbursts of overbreeding and harmful lifestyles.  On a visit to Mayan ruins in Guatemala, Childs discussed their collapse, the result of a combination of factors.  “The issue, ultimately, was carrying capacity.”  Over the years, I’ve often seen people sharing their opinions of the Earth’s carrying capacity for humans.  Estimates usually range between 100 million and 15 billion, as if there is one correct answer.

Actually, the long-term carrying capacity is constantly changing, and these days it’s getting smaller and smaller.  Ocean acidification, chronic overfishing, and other harms have sharply reduced the vitality of marine ecosystems.  Chronic forest mining, soil mining, and industrialization have sharply reduced the vitality of terrestrial ecosystems. 

The fossil energy bubble enabled a huge temporary spike in carrying capacity, but as we move beyond peak, we’ll discover that the long-term carrying capacity is far less than it was 10,000 years ago, when the ecosystem enjoyed excellent health.  Climate change is likely to reduce it further still, as large numbers of plant and animal species go extinct.

There have been five mass extinction events in ages past, and we are now in the sixth.  Childs takes us on an amusing visit to the site of a catastrophic mass extinction, the state of Iowa, where 90 percent of the ecosystem has been reduced to agriculture.  He and a buddy spent two days hiking through fields, dwarfed by tall stalks of corn (maize), during a week of blast furnace heat. 

They were looking for signs of life besides corn, and they found almost none.  The ecosystem was once home to 300 species of plants, 60 mammals, 300 birds, and over 1,000 insects.  “This had historically been tallgrass prairie, one of the largest and most diverse biomasses in North America where a person on horseback could not be seen for the height of the grass.”  The sixth mass extinction is unlike the previous five, in that it is the result of human activities, an embarrassing accomplishment.

Yeast devours sugar and converts it into alcohol and carbon dioxide.  When yeast are added to a vat of freshly pressed grape juice, they plunge into a sweet paradise, and promptly produce a bubbly population explosion.  The alcohol in the vat will keep increasing until it reaches toxic levels, at which point the yeast experience a mass extinction event, the tragic consequence of living in an artificial environment constructed by thirsty alcoholics.

Childs believes that civilization and human domination of the planet waited until recently because we thrive in warm weather.  Humans evolved in a tropical climate.  Eventually, we migrated into non-tropical climates, and developed the skills and technology necessary for surviving in chilly weather, but the ice ages were a time of struggle, not a sweet paradise.  Then, a freak thing happened.  The weather got warm, and stayed warm, for 10,000 years.  Suddenly, we were like yeast in grape juice.  Yippee!

The 800-pound gorilla in this book is climate change, and concern about the decades that lie before us.  Childs cites the views of a number of scientists, and they are all over the place.  A loose cannon at the EPA says that global warming is a hoax, but the others agree that the climate is warming, and humans are the primary culprits.  Some think that we’ve passed the tipping point, and all ice will soon be gone.  Others think that if emissions are reduced, disaster might be avoided.  One is sure that technology will fix everything — geoengineering will allow us to control the planet’s climate like a thermostat.  Another says that humankind will be gone in 100 years.

Climate history tells us that global temperatures commonly swing up and down, sometimes as much as 10° to 12°C.  Huge temperature swings lead to extinctions, but life on Earth has persisted.  The current jump in temperature is unlike the previous ones in that it is the outcome of human activities.  It is the result of a unique combination of factors, with no historical precedent.  Humans are unique in being able to adapt to a wide variety of ecosystems, but ecosystems are far less adaptable to sudden climate shifts.  Agriculture is on thin ice, as are seven billion people.

In a hut on the Greenland ice sheet, Childs had a long chat with José Rial, a chaos researcher and climate change scholar.  Rial understands that nature is highly unstable, and quite capable of rapid and unpredictable changes.  “What we study doesn’t always help us predict very much, but it helps us to understand what is possible.”  Childs added, “He knows that the actual future is the one we never expect.”

Childs, Craig, Apocalyptic Planet — Field Guide to the Everending Earth, Pantheon Books, New York, 2012.

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