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.