[經濟學人] 人定勝天？火山讓強大科技臣服！

冰島火山爆發並未成傷亡，只讓歐洲的天空安靜了近一星期。歐洲當局一開始的態度是只要火山灰散佈於空中，就會影響飛航安全，因此依照電腦模擬的結果，下令可能出現火山灰的地區全面停飛。但各方壓力下，歐洲當局竟改變了立場。新安全標準的制定方式並未公開，這確實會讓人有些懷疑，但並不表示新安全標準有問題。

如果事前能有更好的政策，就能避免許多混亂。火山灰的距離影響難以控制，因此與其他天災相比，這方面的研究也比較少。但事實上，許多歐洲重要機場位於火山國家的下風處，只是全球航空工業崛起之時，恰巧碰上了火山活動較少的時期。

一座火山就讓人類的強大科技臣服，讓人有種奇妙的滿足感、甚至有些興奮。這種崇敬感可以提供慰藉和激勵人心，卻不適合用來制訂政策。因為在大自然面前，人類並不是完全沒有力量。

目前的科技無法阻止火山爆發或地震，甚至連預測都沒有辦法。但人類可以適應、處理這些天災。從許多方面來看，天災造成大量傷亡是經濟發展不足的表徵，海地和智利地震就是很好的例子。如果火山灰真的危險到必須全面停飛，其他形式的交通方式一定可以滿足歐洲的需求，只是成本較高。

只有極少數的天災可以真正影響全球化世界，例如超大型火山爆發、行星撞擊等。但這些事件極少發生，更重要的是，理論上人類可以預測行星撞擊，甚至有機會改變行星的軌道。在這裡，人類似乎克服了自然。

這時應該提一提氣候變遷。人類在大自然面前多麼渺小，不該成為忽視危機、不思解決的藉口。照顧一座星球必須未雨綢繆，該處理的問題可不是只有火山。

經濟學人英文原文

The Economist - After the volcano

Disasters are about people and planning, not nature's pomp

IT IS a peculiar, if blessed, sort of natural disaster in which nobody dies. The Icelandic volcano Eyjafjallajokull produced a thrilling show—and may continue to do so—but did most of its damage simply by shutting down air traffic in and out of large parts of Europe for nearly a week. Rather than bereavement, it brought the eeriness, and sometimes the joy, of displacement. Colleagues were absent from their desks, and teachers and pupils from their classrooms; the clear blue skies were bereft of the silver needles that sew the world together. Birdsong made loud the silence of the jets, florists' vases missed the bright blooms of far-off fields, and far-off farmers missed the cash those blooms would have brought. But, this time, almost all that went missing will be returned.

Two arguments spout up from this demonstration of earthly power. The first is immediate and practical: was all this chaos man-made—an immense and costly overreaction by regulators to a spectacle that posed only a minor and manageable risk? The second is more philosophical: what does this say about man's apparent inability to control nature?

To fly or not to fly

The initial position of Europe's regulators was that the safe level of volcanic ash was, in effect, zero, thus grounding all flights in the broad swathes of sky which computer models said could be tainted. The fact that this regulatory stance changed in the face of an affluent cadre of displaced people, airlines feeling the pinch, a looming threat to some supply chains and (in Britain) an election, makes it all the more suspicious. Areas with low concentrations of dust and ash are now suddenly deemed navigable, and aircraft passing through them will be given thorough post-flight engine inspections (see article).

How exactly the new safety threshold came to be set at 2,000 micrograms of dust or ash per cubic metre is not clear; the figure appears to have come from engine manufacturers, but the evidence on which it is based has not yet been made public. Regulations without a clear and open argument behind them are worrisome. But that doesn't mean the threshold, equivalent to about 100 times the typical level of dust in the atmosphere at ground level, is necessarily a bad one (test flights found patches of dust of up to 20 times normal levels). And the previous position that there was no safe level clearly lacked any sort of evidence base at all.

Had better policies been in place beforehand, much inconvenience might have been avoided. But it is wrong to dismiss the week's woes as an over-precautionary fuss over nothing. Northern Europe has many hub airports downwind of one of the most volcanic countries in the world, and the emergence of the global aviation industry just happened to coincide with a period of relative inactivity there. Some of Iceland's volcanoes can shoot hundreds of times as much gunk into the atmosphere as Eyjafjallajokull has, and over long periods. There are other volcanoes, notably in the American north-west and Japan, capable of disrupting a lot of airspace around big cities. The fact that the long-distance risks posed by volcanoes are not, for the most part, insurable seems to have led to them being less well studied than other kinds of natural disaster. A wake-up call was needed, and it has been sounded. The new regulatory approaches now need to be openly justified, and perhaps taken further.

With great power comes great responsibility

But the week of absences also offers a less obvious lesson. One of the things that went missing in the shadow of that volcanic dust was a sense of human power. And as with the quiet skies, this absence found a welcome in many hearts. The idea that humans, for all their technological might, could be put in their place by this volcano—this obscure, unpronounceable, C-list volcano—was strangely satisfying, even thrilling.

Such pleasure in the face of overpowering nature, as seen from a place of safety, was at the heart of the idea of "the sublime" as expressed by the great conservative Edmund Burke 250 years ago, and its aesthetic and spiritual allure remains strong. The sublime offers solace and inspiration, but it makes a poor guide to policy. For humans are not completely powerless in the face of nature: rather the reverse.

There is no technology to plug volcanoes which pierce the earth's crust, or to bind the faults which cause earthquakes. There is not yet even a science for predicting when faults and volcanoes will let loose. To that extent, mankind is still vulnerable to the vagaries of the planet. But the story of human development is one of becoming better at coping with them.

Death by disaster is in many ways a symptom of economic underdevelopment: witness the very different consequences of the earthquakes in Haiti and Chile. In general, richer places and richer people are better able to survive and rebound. More interconnections provide more ways to mobilise resources and explore alternatives when things go wrong. If the Eyjafjallajokull plume had been as risky as it first appeared and long-lived to boot, such interconnectedness would undoubtedly have provided ways to keep Europe supplied, though probably at substantial cost and with a fair bit of lasting disruption. The apparently sublime power of the volcano was largely the result of an initially supine reaction.

Very few events are able to perturb an increasingly globalised world. The Indian Ocean tsunami of 2004 was a murderous event, but the world pushed on and many areas recovered quickly (see Buttonwood). For a natural disaster to represent a global threat, it has to act on a global scale. An eruption of hot plasma from the sun, called a coronal mass ejection, which could do damage to electricity grids over an entire continent, might fit the bill. The largest volcanoes might cause short-term climate change profound enough to reduce agricultural production precipitously in many places at once. A large asteroid strike would do yet more damage.

These are, though, rare events. Very large coronal mass ejections are thought to happen every 500 years or so (the most recent was in 1859). Volcanoes that change climate enough to affect agriculture round the world are perhaps 100 times rarer than that, and cataclysmic asteroids rarer still. What is more, such asteroids could, in principle, be identified and, with plausible technology, nudged aside. Here Burke's sublime is turned on its head, and human capability seems to humble nature.

This is worth applying to climate change. Many of Burke's descendants find it difficult to believe that something as big as the earth's climate could really be at risk from human activity, and even harder to think you could do something about it. But the risk, if not full certainty about its consequences, is there. Moreover, the idea of a counterbalancing, "geoengineered" cooling to counteract some aspects of climate change is worthy of study and discussion. Large volcanic eruptions spread cooling palls through the stratosphere. Techniques for doing something similar in a less dramatic way are plausible.

When people talk about the charms of powerlessness in the face of nature, part of what they are saying is that they don't want to be bothered with facing up to what humans can do, and to what they might have at risk. The business of looking after a planet requires being bothered in advance—and not just about little matters like volcanoes.