Models are very much in vogue. Not the skinny ones in the magazines, but the successors to the crystal ball. It’s somehow scary that computer modelling is now indispensable. Hitherto unimaginable number-crunching capabilities permit the generation and projection of multiple scenarios for every scientific and social policy purpose. Climate scientists model the long-term effects of greenhouse gas emissions; military strategists model conflict scenarios; Treasury models the economic effects of internal and external trends; the Bureau of Meteorology models next week’s weather; social scientists model the winners and losers in tomorrow’s society.
So what exactly is a computer model? My mate Fred, an IT expert, tells me that modelling is electronic cooking; baking a data cake if you like. Toss together in a large processor three cups of historical records, a generous handful of trend lines and a sprinkling of assumptions. Crack in a couple of parameters and beat with a smidgeon of faith until smooth. Pour the mix into your desktop oven, select your timescale, solemnly intone post hoc, ergo propter hoc and settle back with a good e-book until the machine goes ding and behold: out pops your nicely-browned terabyte torte. Ice it with certainty, feed it to a hungry politician and tomorrow it’ll be policy. What could be simpler?
But wait. Is our recipe really foolproof? Is modelling really the answer to every need to project desired outcomes? For example, I’ve read that policy recommendations by the Murray-Darling Basin Authority were informed by inaccurate modelling. Not just a little bit wrong, but very wrong. How could that be? Too much faith, perhaps, or the use of plain instead of self-raising data? Food for thought. And there are claims by deniers and sceptics that modellers of anthropogenic climate change are simply compulsive followers of others' assumptions. These are not isolated cases. Remember Treasury’s modelling for the economic effects of the carbon tax as we moved forward to Julia's clean energy future? Was it really based on rigorous analysis? Was there really only a ten to thirty percent chance that your average consumer would be out of pocket by more than $2.80 a week during the next three to fifteen years? The tax was discarded, so we'll never know. But fear not. The modellers are hard at work on new projections, this time for a plan to borrow now and pay much later. I like the idea but fear the outcome.
Consideration of these weighty matters is too much for my ageing brain, so I call Fred. ‘Want to go fishing?’
‘Love to,’ he says sadly. ‘But the models are showing only a four to nineteen percent chance of catching a legal sized fish between Cape Moreton and Cairns due to unforeseen variations in tide levels for the next three days. Apparently it's the old global warming thing again. Waste of time, mate.’
I chuck the idea and head for the beach while it’s still there. The models tell me that it’ll be around for another few decades before we share the fate of Atlantis, but what if they’re wrong? What if 2100 comes tomorrow? It’s a worry.