Weather Forcasting

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Computer Modelling, Climate Change and Human Gullibility

One day I was talking to a man, well into middle age, in a pub near the Deben Estuary in Suffolk. He was born into a poor family, and did not have a radio. He said he used to know within 20 minutes when the High and Low Tides would be, could always tell the weather for the next day, and nearly always how it would be for the next few days. Eventually he could afford a radio, and then regularly listened to weather forecasts. One day he realised that he could no longer tell, for himself, how the weather would be. That was fifty years ago… The satellite era had hardly begun, computers were large and clumsy, the internet and mobile phones were not even a gleam in anyone’s eye.

Weather forecasting now depends on the satellites orbiting our earth, looking at and measuring everything (including you and I). The data is fed into computers and models are used to forecast the weather. There is, though, a limit to the amount of data that can be utilised, and I remember a lecture by a leading meteorologist to the Royal Society who emphasized that approximations and assumptions in modelling were unavoidable. And that was before chaos theory (a butterfly flaps its wings in the Amazon, and eventually there is a hurricane in Louisiana).

In the UK, the Meteorological Office is responsible for weather forecasting, and, like everyone now, their forecasts are based on computer modelling. In 2009 they forecast a “barbecue summer”- it was very wet. They forecast that the winter of 2010 would be “warmer than usual”- the December was the coldest since records began in the eighteenth century. In 2007 in a paper in the journal Science, it predicted that by 2014 the world temperature would have risen by as much as 0.3C, possible by 0.5C, and that four of the five years after 2009 would be warmer than the warmest year so far, which was 1998. In fact, during the last ten years, world temperatures have fallen slightly, and in the five years since 2009 the 1998 record has not been exceeded once. The computer model used is based on the assumption that world temperature will rise with the rise in atmospheric CO2 levels. Subsidies for green energy production in the UK- based on the same assumption- is costing each family £1600 a year.

Anyone who loves German wine will know that average temperatures in Europe north of the alps have risen since 1993. What have been the best vintages in Germany since 1920? They were: 1921, 1934, 1937, 1947, 1949, 1953, 1959, 1964, 1971, 1975, 1976, 1983, 1989, 1990. That is, there were on average two years each decade when very good or outstanding wines were produced. From 1993 onwards, good wines have been produced in at least some of the thirteen wine regions of Germany every year, except 2013. And some of us remember successions of rather dreary summers in decades past- which is why everyone who experienced it can recall the wonderful summer of 1976, when London seemed to be in the Mediterranean region. So, it’s warmer now. But why? And will it go on?