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Nature and Society Editorial - February-March 2006 Last year a political dispute arose about the idea of testing and grading the literacy and numeracy skills of young school children. It was the grading that provoked many educators, not the need for the skills themselves; these skills are seen as essential for successful participation in modern life. Unfortunately, understanding the complex problems humanity faces requires many skills that seem to be lacking in various sectors of society. One glaring example is the problem of growth. Our politicians, economists and business leaders are fixated on the idea that we need growth, not recognising that growth is the cause of many of our problems, not the answers to them. In December Albert Bartlett, a retired professor of physics from Colorado, visited Canberra and Adelaide to give a lecture “Arithmetic, Population and Energy”. Bartlett has spent the last twenty years trying to raise the alert on our passion for growth. Growth unchecked is totally unnatural and definitely not beneficial. There is a general lack of understanding of the way apparently small amounts of growth add up. Long ago school children learnt to calculate compound interest, but this only related to money, how much interest you could get from the bank (in the absence of bank fees!). Without revisiting the process of calculating compound interest, take note of the following result. One per cent growth per annum, compounded over seventy years results in the doubling of whatever you are counting. But if growth is two per cent then doubling time is halved – thirty five years. If growth is five per cent doubling takes fourteen years and growth of ten percent gives a seven year period. Forget money, think population, resource consumption, energy usage, and think what this means. The effect of this growth can be illustrated in many ways. There is the analogy of the lily pond where the lilies spread exponentially, doubling the area covered each day. At first the area covered was so small it did not seem to matter at all. Then it got to one eighth, one quarter, one half full; the next day the pond was completely covered. You may prefer the microbes, happily doubling their numbers in a flask each day. At half full they sent out some scouts who found the untold wealth of three new flasks to live in. Wow! Next day their original flask was full, the day after, one of the new flasks was full, and the following day the remaining two flasks were full. Their bonanza was an illusion. Exponential growth had eaten it all up. So when an energy and resources minister announces a new find of oil or gas and says we now have reserves for ten, or fifty years at current rates of usage, beware. Our usage is not steady, it is increasing. Worse still we are seeking new markets to sell the resource off even faster. Our new resource provides an illusory security of supply. Another thing to consider about exponential growth is that with every doubling the new number is greater than the total of all that has gone before, a very sobering thought. You can try a simple three by three grid thus, with the number doubling in each successive square. Note that four is greater than one plus two, and that 256 is greater than the sum of all the previous numbers. The population of humans could double slowly over millennia and not be too obvious, but our population numbers and resource use have reached the stage where a future doubling would be disastrous. We do not have a new Earth to colonise and even if we did, if growth continues we would fill that, too. Who ever heard a doctor reassure a patient that their cancer was robust. A more normal term would be malignant or aggressive, neither remotely reassuring. As Prof Bartlett says, the failure to understand exponential growth is a major problem in our society. Another problem in mathematical understanding showed in a letter to Canberra Times a few months ago. The writer stated that as the carbon dioxide concentration in the atmosphere had increased from 270 parts per million (ppm) in 1800 to 360 ppm today, this means that the composition of the atmosphere has only changed by 0.009 per cent. Such a small change can be of no consequence: the more usually quoted figure of a 33 per cent increase in CO2 is a case of lying with statistics. The letter writer had raised an important point: statistics can be presented in different ways. Frequently one way makes the figures look serious (eg. a big increase) and another equally valid way trivialises them. The form of presentation can be chosen to achieve a desired effect. In this case the writer apparently does not understand that this tiny proportion of CO2 (along with water vapour et al) is what keeps the earth at a habitable temperature rather than in a deep freeze. An increase in that proportion will raise the temperature an uncomfortable or even dangerous amount. A tiny amount of poison might not kill, but a slightly increased dose might do the victim in. Professor Bartlett bemoaned the inability of so many politicians, economists and others to understand the problem of growth, when children can understand it quite easily. It is probably not a matter of numeracy but of preconceptions. If you have always believed that growth is good, that there can be technological fixes for everything, that humans are special and limitations are for others, then you can think that growth can continue for ever. Numeracy is a useful skill but a broad knowledge of the history of life on earth, an appreciation of ecology, biology and earth sciences, and the interconnectedness of all these with the history of human civilisation is essential for the correct interpretation of the mathematical problems discussed above. Could we hope not only for numeracy and literacy testing of all people in powerful positions, but also for tests of their ecological, general scientific and historical and sociological understandings too? February-March 2006 edition accessible here
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