Home Object Activities Contact Who's who How to join NSF How to support NSF What's on Nature and Society Editorial Recently Australia’s population reached twenty one million. The next week Australasian Science published a report on a study by the academy of Technological Science and Engineering (ATSE) into how Australia would cope with a population of thirty million by 2050 (called 30/50 for brevity). The study was commissioned by the Scanlon Foundation “which believes that the future prosperity of Australia, underpinned by population growth, will depend on our ability to maintain social cohesion in a society with even more cultural diversity than we have already accommodated.” The study findings conclude, amongst other things, that there are no inherent physical, resource or technological barriers to achieving an increasingly prosperous society of that size. In this study, as in many others, there seems to be no limit to technological optimism. Apparently Australians will be twice as wealthy as they are now, with a high level of car and private plane ownership. We will find new fuels to run cars and fly planes! Undoubtedly a great deal of thought and modelling went into this study, by people who are highly intelligent and mathematically competent. However all modelling is only as good as the inputs into it, and the assumptions that form its base. In a book called Useless Arithmetic: why environmental scientists can’t predict the future, by geologist father and daughter OH Pilkey and Linda Pilkey-Jarvis, the authors show how signally we have been unable to model coastal erosion and our efforts to remediate the problem, amongst other things. Fisheries modelling has likewise failed. A fisheries expert on The Science Show (7 July), discussing the ongoing collapse of many of the world’s fisheries, commented that the models were good at describing what had happened in the past, but not good at prediction, maybe because we are making the wrong assumptions. One of the rules that had been expected to preserve fisheries had actually proved to be damaging. Establishing a minimum legal size for fish caught was expected to preserve the stock, by giving juveniles time to grow up. What it did was to remove most of the large fish. It happens that the largest and oldest fish are the most fertile, so the practice removed the best breeding stock. The truth is that our knowledge of natural systems is not complete enough for us to ‘manage’ them in any sustainable way. The best response we have devised to date for managing fisheries is to establish large enough no-take areas to permit the fish to manage themselves. Scientists are now calling for thirty per cent of the oceans to be protected in reserves, in the hope that this will prevent the devastation of all fisheries. The 30/50 study found no apparent insurmountable engineering, health, scientific, economic or environmental barriers in meeting the water needs of their scenario. It focussed on urban water, since population growth will probably be concentrated in existing cities. Producing food requires a lot of water, and is usually done in the country, even for urban populations, so it seems strange to ignore this. Australia has been seriously worried about production of food in our ongoing drought-affected areas. Suggestions have even been made of flying in cabbages from China. The USA is already importing a wide range of foods from China; Europe flies in fresh vegetables from Africa. Yet both China and Africa have their own water problems. Australians already expect our farmers to provide a lot of food and textiles for export, and in the future will also require them to produce more of these, possibly along with crops to produce fuel and plastics. ATSE’s report was predicated on the necessity for populations to continue growing, so it is not surprising that the nasty fact has been overlooked that the earth is finite, that populations cannot continue to grow. Of all the mathematical facts that modellers, politicians and all others need to be aware the most important is that continuing growth in population and consumption in a finite world is impossible. Sometime growth must stop, either because it causes its own collapse, or because we have the sense to put an end to it. It is fairly generally recognised now that we must reduce greenhouse gas emissions by a very large percentage, very soon. This will only be done by increasing efficiency and by a change to non-polluting technologies. What seems to have escaped notice is that all the gains in efficiency will be cancelled out by having increasing numbers of people, increasing numbers of buildings and consumer goods. Sometimes it is said that the more affluent we are, the better we can afford to look after the environment. This seems to have been given the lie by a new report showing that the most affluent suburbs are the worst emitters. Certainly as countries work their way up the economic ladder, their emissions increase. No matter what technological wonders our clever brains devise the environment will have the final say. It is our choice; vastly unpleasant collapse through disease, starvation and war, or a realisation that growth in numbers and consumption is unsustainable. The longer we go on thinking that prosperity depends on the growth of population, the harder it will be to bring that growth to a gentle halt. August - September 2007 edition accessible here Back to top ________________________________________________________________
|