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Matt Ridley is the author of provocative books on evolution, genetics and society. His books have sold over a million copies, been translated into thirty languages, and have won several awards.

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England's wettest June -- noise, not signal

The Met Office keeps getting 3-month forecasts wrong on the warm side

I wrote the following op-ed in The Times (behind a paywall) on 2 July.

As I cowered in my parked car in a street in Newcastle last Thursday, nearly deafened by hail on the roof of the car, thunder from the black sky and shrieking girls from the doorway of a school, a dim recollection swam into my mind. After inching back home slowly, through the flooded streets, I googled to refresh the memory. On 23 March this year, the Meteorological Office issued the following prediction:

"The forecast for average UK rainfall slightly favours drier-than-average conditions for April-May-June as a whole, and also slightly favours April being the driest of the 3 months. With this forecast, the water resources situation in southern, eastern and central England is likely to deteriorate further during the April-May-June period."

That went well, didn't it? April-May-June was the wettest ever in England, though not in Britain. According to the private forecaster MeteoGroup, June was probably the wettest in England and Wales since 1860, the dullest since 1909 and the coldest since 1991. The water resources situation, far from deteriorating, is a cup that overfloweth.

The Met Office's track record of short-range (5-day) forecasting is, in my experience, very good and getting better, but its longer-range predictions have often been not just badly wrong, but consistently biased on the warm, dry side.  In 2007, it wrongly forecast a warm summer. In 2008 it wrongly forecast a mild winter. In 2009, it said "the chances of getting the barbecue out are much higher than last year" but the summer was a washout. Also that year it said that the trend towards milder winters was likely to continue, whereupon a savage winter followed.

Chagrined, it said it would give up seasonal forecasting, but continued to produce much the same information in three-month forecasts. In October 2010 it saw "a very much smaller chance of average or below-average temperatures" in the coming winter shortly before the coldest December for 100 years. These mispredictions were not without consequence. The under-preparedness of airports and councils for the big freezes at the beginning and end of 2010 was directly related to the forecasts they had sought.

Now look at the curriculum vitae of the chairman of the Met Office, Mr Robert Napier. He is also chairman of the Green Fiscal Commission and the World Conservation Monitoring Centre, director of the Carbon Disclosure Project, the Alliance of Religions and Conservation and the Climate Group. He is so high up in the church of global warming, he is a carbon cardinal. I am sure he is a man of great integrity, but given this list you have to wonder if one of the organizations he chairs does not occasionally - and perhaps unconsciously - aim to please him with warm long-range forecasts.

Of course, these days the narrative has changed and we are usually told to expect more extreme weather events as a result of climate change, rather than a warming trend per se. If June was indeed the wettest since 1860, that is extreme, but with only a few centuries of data, records are bound to be broken from time to time -- and it is not much of an extreme that fails to beat a 152-year record.

Likewise, in November 2009 when torrential rain swept away the bridge at Workington, a Cumbrian rain gauge recorded the greatest rainfall in any 24 hour period since British records began -- a total of 316mm (12.5in). Astonishing: till you read that it did not break the "day" rainfall record, which is measured from 9am to 9am and which is still held by Martinstown in Dorset on 18 July 1955 - 279mm. That's before global warming was supposed to have shown up.

What, in other words, was so special about the climate in 1860 or 1955 that it too produced extreme events? The truth is that for all the talk of climate change, a trend of half a degree of warming in half a century is still very much less relevant to airports, wedding planners or breeding birds than the random and occasionally extreme variation that is bound to show up in some years with or without man-made climate change. As they say in physics, the noise is greater than the signal. It certainly was last Thursday.


Update 1: The Times pubpished a letter from Bob Ward calling my article "rather silly". Since his letter confirmed the accuracy of my main point -- that no trend can be discerned in the signal --

"While he is right that we cannot yet detect the signal of climate change within the relatively small datasets of extreme weather events in the UK..."

and contradicted no other of my arguments, I thought his letter was "rather silly".


Update 2: Paul Homewood has some good graphs here, showing how trend-free June's weather in England still is.

here is one of his charts.