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Global Warming and the Earth's Magnetic Field

Posted on Saturday, April 1, 2006.

Many orienteers will be aware of the classic 1996 paper 'Predictions of future magnetic field reversals' by Professors Howard Orchard and Alberto Ximenes of the Institute for Applied Physical Research (IAPR). Now a follow-up study 10 years later has made dramatic new predictions that may have an even more fundamental impact on the sport of orienteering.

Professors Orchard and Ximenes, in conjunction with new co-worker Colm O'Neary, have been looking at the possible impact of global warming on the earth's magnetic field. They have developed a new computer model which, combined with the latest developments in computer processing power, has allowed them to make predictions of previously unimaginable accuracy. O'Neary explains the results: 'What we have found is that warming at the earth's surface is eventually great enough to have an impact further inside the earth. It is well-known that heating a magnet is one method of destroying its magnetism. Our model shows that the increased heat in the earth's core is sufficient to destroy the earth's magnetic field totally. Ten years ago we were worried about the poles moving around. Now we are predicting there won't even be a magnetic pole.'

The British Orienteering Federation is thought to be considering introducing an emergency rule that bans both the use of compasses and the printing of grid lines on maps. This would force orienteers to become used to navigating without compasses, in preparation for the day when there is no magnetic field. They are also considering introducing a rule that all maps must be printed on round pieces of paper, with no text or other information which might indicate where north is. No technical solution has yet been identified to the problem of getting a circular map in a circular plastic bag and then heat sealing it. The ISOM mapping specification will also need be revised to remove all those symbols which are currently defined as 'oriented to north'. One suggestion being examined is that OCAD and other mapping software could be updated to align such symbols randomly.

The International Orienteering Federation will also be examining its rules, and changes can be expected soon. Some people have claimed that banning the use of compasses will reduce the advantage of the Scandinavian countries over some of the lesser nations, since everybody will be forced to develop new navigational techniques. The example of ex-World Champion Pasi Ikonen from Finland, who won gold in the Short Distance race in 2001 without using a compass, indicates that the Finns at least may have been preparing for this for some years.

O'Neary summed up the new findings: 'We are 100% confident in the computer model and the physics behind it. We are only just becoming aware of the huge implications of this study. Orienteers may think they are badly affected, but we are confidently predicting that this will be the end of pigeon racing as we know it.'

At least there is a positive note to end on. The computer predictions show that it will take nearly 100,000 years for a sufficient temperature rise to occur to cause the magnetic field to disappear. The study is therefore unlikely to cause quite as much concern as was initially thought.

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The Institute for Advanced Physical Research

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