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Super-cat that will threaten life on Earth: it is only a matter of when
BILL MCGUIRE, professor of geophysical hazards and director at the Benfield UCL Hazard Research Centre, University College London, warns of some of the catastrophic risks facing Earth CATASTROPHE insurance is, or certainly should be, underpinned by the capability to make adequately accurate predictions about future floods, storms, and earthquakes, so as to ensure that portfolios are not unreasonably exposed to large, unforeseen losses.The over-riding lesson to be learnt from the events of September 11, however, must be expect the unexpected.
As ever, changing circumstances continue to lead the insurance industry by the nose. Following the Northridge quake in 1994, better seismic risk assessment was the sought-after grail, while following Hurricane Andrew’s concerted attempt to obliterate Miami, tropical cyclone forecasting was all the rage.
Inevitably, for the last six months, terrorism has taken centre stage, with industry researchers attempting to quantify future terrorist threat using game theory and other esoteric mathematical jiggery-pokery.
If insurers are not to be caught out again, it is clear that they must become proactive rather than reactive, adopting a ‘clear horizon’ approach that seeks to identify and quantify future threats before they happen.
Inevitably, any such policy will find itself uncovering rare events characterised by low frequency but high impact. Squarely into this category fall those phenomena labelled by hazard scientists as global geophysical events and defined as natural catastrophes with the potential to have a detrimental physical effect on the entire planet or at least a substantial fraction of it.
The last few years have seen a growing awareness of such shadowy phenomena as asteroid and comet impacts, volcanic super-eruptions, and giant tsunami, which have now become, as it were, respectable passing from the rather airy-fairy realm of science fiction to the cold, hard world of hazard science.
If one could put a finger on just when this transition occurred, it would be July 16, 1994, when the first of 21 chunks of fragmented comet ploughed into the giant planet Jupiter, creating impact scars larger than our own world.
Suddenly, the Earth seemed a more fragile and vulnerable place, with the human race clinging to life only with the consent of Mother Nature. Within months, scientific programmes were in place to find and map all those objects that threatened to collide with our planet, while national governments including those of the US and the UK established task forces better to assess the threat.
At the same time, popular perception was raised by two Hollywood blockbuster films, Armageddon and Deep Impact, which detailed, with varying degrees of scientific plausibility, what will happen when the Earth is next struck by a large object from space.
Note here that I use the word will rather than is. Gaining acceptance that global geophysical events such as asteroid or comet impacts are certain rather than just possible remains difficult, and getting the message across that such phenomena constitute normal if infrequent behaviour, in geological terms, is still a struggle.
While experts agree on the size-threshold of an impactor capable of causing global mayhem something on the order of 1 km to 1.5 km there is still some discussion over the frequency of collisions with such objects, with estimates ranging from every 100,000 to 300,000 years.
There is also some debate about how many threatening bodies there are out there, and the number of large Earth-threatening asteroids may be as low as 500 or as high as 1,200. So far we have spotted less than 400.
The effects of an impact event on the Earth and our society depend upon the energy of the collision. This is largely size-dependent although comets can travel at double the speed of asteroids.
A 10 km did for the dinosaurs around 65m years ago and a similar collision would obliterate our race. An object in the critical 1 km to 1.5 km size range would be sufficient to obliterate a small country or state and would kick up enough debris to block out the sun’s rays and lead to a world-wide freeze, sometimes referred to as a Cosmic Winter. Resultant death tolls of the order of a billion have been estimated, largely due to starvation related to global crop failure and subsequent famine.
As if the threat from space was not sufficient, future catastrophes are also brewing beneath our feet. A couple of times every hundred millennia, an explosive volcanic blast several thousand times greater than that which blew Mount St. Helens apart in 1980, ejects sufficient gas and debris into the stratosphere to dramatically reduce the amount of sunlight reaching the surface.
The last time this happened, at Toba in Sumatra, a global freeze this time a volcanic rather than a cosmic winter followed, which some anthropologists believe reduced the human population to just a few thousand individuals.
The Earth does not run like clockwork and natural catastrophes do not operate to a timetable, but the fact that some 74,000 years have passed since the Toba eruption should start us thinking.
Add to this the fact that we are currently only monitoring a few hundred of the world’s 3,000 or so active volcanoes and the cogitation rapidly turns to concern. Yellowstone Park (Wyoming, US) is probably the best-studied super-eruption source, having produced three gigantic blasts during the past 2m years.
The last, around 650,000 years ago, led to volcanic debris 20 cm deep accumulating more than 1,500 km away, and ash falling in what is now El Paso and Los Angeles.
A similar event today would bring the US economy to its knees, notwithstanding its effects on the planet’s climate as a whole. Yellowstone is closely monitored and likely to provide decades of warning of a new super-eruption.
What is happening today at unmonitored volcanoes in the southern Andes or the jungles of south-east Asia is on the other hand anyone’s guess.
Both super-eruptions and the aforementioned asteroid or comet impacts depend upon the atmosphere to spread their effects worldwide, in the case of giant tsunami regularly incorrectly referred to as ‘tidal waves’. However, the oceans are the transmitting medium.
Unlike the run-of-the-mill, though deadly, tsunami generated by submarine earthquakes, giant tsunami which may exceed 100 m in height result from the collapse of volcanic ocean islands.
Evidence exists for such waves pounding the coastline of eastern Australia following massive landslides on the Hawaiian Islands around 100,000 years ago.
Much more recently, attention has focused on the Canary Island of La Palma, where a mass of rock the size of the UK’s Isle of Man, started to slide seawards in 1949.
A recent model of the future collapse which could occur in hundreds or thousands of years’ time predicts waves up to 50 m high crashing into the east coast of the US and Caribbean some eight to12 hours after collapse, with the UK, southern Europe, South America and North Africa also affected.
The depressing lesson, then, is that natural catastrophes on a planetary scale are waiting in the wings ready to exact an enormous toll on the global economy, and by default on the insurance industry. But can anything be done? As is often the case, the answer is yes, but only if we have sufficient warning.
Although the physical damage arising during the aforementioned scenarios will inevitably be beyond experience and economic and insured losses unprecedented, complete collapse of the global economy and social fabric can be avoided by taking appropriate mitigatory measures, including evacuation, emergency powers and rationing.
Whether the insurance industry in its present form could survive a global natural catastrophe is questionable, and it is clearly too much to expect for companies to build contingency funds to cushion its effects.
There is no such thing as too much knowledge, however, and in the aftermath of September 11 it can do the industry no harm at all to begin to familiarise itself with the far greater natural threats that it faces going forward.
* Bill McGuire’s new book, A Guide to the End of the World: Everything You Never Wanted to Know, is published by Oxford University Press at £11.99
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