Article: We're In This Together

Published Wednesday, April 23, 2008 by Dan Gainsford | E-mail this post

E-mail this post



Remember me (?)



All personal information that you provide here will be governed by the Privacy Policy of Blogger.com. More...


We’re in this together
What we’ve lost sight of in the global warming debate is that while we may be doing
terrible things to the planet, it is capable of doing much worse to us
BY MARQ DE VILLIERSMARQ DE VILLIERS

is the Governor-General’s Award-winning author of Water: The Fate of Our Most Precious Resource. His latest book is Dangerous World.
It is common knowledge — except perhaps on the wilder shores of Creationism — that everything on Earth, the plains, mountains, canyons, lakes, the very shape of the continents, is the product of processes that were, and still are, at work far below the surface. Even schoolkids, after all, learn about plate tectonics. Now, webcams on the net show molten rock bubbling from volcanoes in real time; pictures of the San Francisco expressway tottering in a big quake are commonplace; the Asian tsunami of 2004 made its way into billions of living rooms through amateur videos and cellphones.

But still ... just how very malleable, how unnervingly plastic, this seemingly solid Earth of ours really is, and how very unstable its apparently immutable surface, is something we are only recently coming to understand.

A German-American satellite recently demonstrated that the Earth’s surface can change far faster than merely drifting continents, faster even than the seasons. On its multiple passes the satellite showed that the Earth’s crust can dip a few centimeters under a heavy regional snowfall, or through changing water levels in the Amazon, or after torrential monsoon rains. Other research has shown that the deep tones of a thunderclap — not the crack that you hear but the almost inaudible infrasound rumbling that follows — can set off small seismic shocks that set the upper crust quivering. Far from being the solid thing that common sense tells us it is, the Earth breathes, shivers, throbs, and pulsates in ways no one would have believed even a few decades ago.

That the moon causes tides in the oceans is a commonplace, of course. But that it causes tides in the apparently solid surface of the Earth is less well known, yet it does — the Earth’s crust is “sucked upward” by the moon’s gravitational pull twice a day, just as the sea is. Less than the sea, obviously — rock is not as malleable as water — but it can rise by a not unimpressive 10 centimetres all the same.

Many people were astonished to learn that the 2004 tsunami was strong enough to actually change the Earth’s rotation by a fraction of a second, setting off a flurry of apocalyptic blogs on the Internet. But this is not so uncommon, after all. Changes of a few milliseconds are really quite routine. The seasonal distribution of water and ice, and even water vapour, can be enough. El Niño, in addition to causing droughts in the southern hemisphere and warmer winters in the American northeast, also changes the length of the day. Filling the reservoir behind the Three Gorges Dam in China altered the rotational period enough to be measured by amateur astronomers. If such a dam burst, it would not only kill hundreds of thousands of people, but make the Earth itself wobble, and slow a little.

This inherent instability has its consequences. We may be doing terrible things to the planet — as we’re reminded almost every day — but the planet is quite capable of doing equally dismaying things to us. We’ve sort of lost sight of this in the global warming debate. Consider these facts: The insurance giant Munich Re issued an actuarial assessment in 2005 that said we can now confidently expect three to four major calamities each year with 50,000 or more casualties. Seismologists are confident that a million-victim earthquake is a certainty in the next few decades. Most probable venue: Central Asia, whose cities have “some of the scariest building codes anywhere.” But it could be Tokyo, at the junction of three restless tectonic plates. Or California — a 2008 report said the Big One should confidently be expected in the next 20 or so years. Some 8,000 mini-earthquakes occur each day, about three million a year — every day, two greater than magnitude 2, and one really big one, a potential city killer, every year.

More than 1,500 active volcanoes have been catalogued, with 10 to 20 erupting at any one time. Yet the biggest three eruptions of the last 50 years happened on mountains that were not thought to be volcanoes at all. In December 2006 the journal Science reported on the work of Maria Pareschi, of Italy’s National Institute of Geology and Volcanology — the same researcher who traced tsunamis resulting from collapses of Mount Etna and Stromboli, among others. “A massive collapse of Cumbre Vieja, a volcano in the Canary Islands, would trigger a towering tsunami that would pummel both sides of the Atlantic,” Pareschi suggested. “Such a collapse — quite probable because it is very unstable — would be 10 times larger than the Etna slide, (itself) an immense geological event. It would overwhelm New York, Miami and Lisbon.” How tall would such a towering tsunami be? Possibly as high as 100 metres. That’s as high as many of the buildings on Wall Street. Nothing on the coast would escape.

You need to look up, too, as well as down; we’re living in a hostile cosmic neighborhood. NASA has been charged with cataloguing the billions of asteroid fragments lurking around between Jupiter and Mars, and to make some hazard assessments. After all, only a century ago a fragment impacted Siberia, near Tunguska. It was just a small thing, maybe 10 metres or so, but had it landed on, say, London, the city would have been obliterated.

In March 2007 a planetary defense conference was summoned by the U.S. Congress, whose attention had been caught by the spectacle, seen live on TV, of a comet wreaking havoc on a planet much greater by far than Earth, namely Jupiter. The assembled scientists then calculated: the probability of a “dinosaur-killer” impact — that is, one that would very possibly end life as we know it — is about one in one million this century. The probability of a civilizationending impact is rather larger — a bit less than one in 1,000 this century. For a smaller, Tunguska-class impact, near the lower size for penetration of the atmosphere, but still large enough to destroy a city, the odds are higher still: maybe one chance in 10 that we’ll get a hit this century. Those are not comforting odds. Here’s what would happen if a kilometre-sized chunk of rock hit, say, the Atlantic Ocean 500 miles off the American coast: At the given speed of 61,000 kilometres an hour (an actual observation of an Earthly near miss in 1950), the 60,000-megaton blast of the impact vaporizes the asteroid and displaces an area of ocean 17 kilometres across and down to the sea floor. Water then rushes back in and waves spread out in all directions. Two hours after impact, 120metre waves, the size of a 40storey building, would reach beaches from Nova Scotia to Cape Hatteras; two hours after that, 60metre waves would have hit the entire east coast and pretty much wiped out most of the Caribbean. Eight hours after impact, the waves reach Europe, where they come ashore at heights of about 10 to 15 metres.

It has always been a commonplace of science fiction that what the world needs is an external enemy to bring its quarrelling populations together. What few of those writers understood was that the “enemy” was not alien spaceships manned by malevolent monsters, but instead the uncaring, impersonal, value-free operations of entirely natural systems that, quite literally, surround and envelop us. Looked at this way, the political and religious quarrels that consume so much of our energy seem increasingly insane, and so does the ruinous “development” we are inflicting on our home.

The real question is politics. If 50 million people can be killed by a tiny mutation of a microbe we can’t even see, if an entire continent can be wiped out by a collision with something we can’t predict, if the global climate can change when a magma chamber a few kilometres square suddenly decides to erupt … why do we spend so much of our time in fruitless quarrelling? It wasn’t at all reassuring that, with the American state of Georgia facing critical water shortages in the fall of 2007, one of the most vigorous political controversies was about whether the governor could legitimately pray for rain or whether that would somehow violate constitutional norms.

Perhaps five angels, or 50, can dance upon the point of a pin, but none of their dancing will affect the course of the tsunami that will be rolling someone’s way quite soon. Or the hurricane that will be coiling its deadly way across the Caribbean this summer. Or the earthquake that will tumble down cities. Or the volcano that will spread its pall of ash and destruction across towns and villages not yet known. Or the rising sea levels that will swamp coastal communities. This is surely where our attention must be focused.

Subscribe

Check this space for filmmaker updates from the road!


Links