Climate is Weather, not the other way round.

Published January 10, 2010 by Sean

I posted this as a comment at the Telegraph Blog, where Christopher Booker is discussing the cost (in any senses) of the Man-made global warming scare. As a reference for foreign readers or readers from the future, Feb ’09 saw a severe cold snap in the UK, with councils running short of grit for the roads, and Dec’09-Jan’10 are giving us our coldest winter for at least 15 years. 2009 CET had some warm months, ending at +0.64 Celsius w.r.t. 1961-90, Jan was -0.8, Dec -1.6. Jan’10 is estimated at -5.75 to 10th, according to NetWeather (the met office is not updated since the 7th.) 1963 had -5.6 for the whole month of January, so this month is not particularly extreme yet.

As many people seem to be grasping, weather and climate are not quite the same thing. Roger Pielke Sr has a blog post comparing the surface anomalies in December against 2009. Very different. Yet the Met Office (who claim to have a good understanding of these matters) have stated that snow will become rare in the UK (March 2000), and repeatedly made (presumably) politically motivated seasonal forecasts. The UK is unusual in that our weather seems to be the residuals of several systems. Sadly, one of the best instrumental temperature records is therefore mostly noise. Following in the theme that localised temperature measurements tell us almost nothing about global climatic trends, how about those poor twisted scrub trees in Siberia which tell us how warm it was there 1000 years ago? On a more technical front, some analysis here shows that Over-fitting is likely to show a historical dip and then a recovery to a mostly unchanging prediction for past temperatures (see figure 4).
Regardless of the meaning of the global average temperature, comparing the trend from 1950, ’60, ’70, ’00, ’01 to November 2009 against the accepted model means shows a statistically significant difference (and remember that the models were designed around the perid of better agreement). Temperatures averaged everywhere are not continuing to rise as they seemed to be in 1980-2000, and yet it was this rapid rise which could not be otherwise explained that lead to the demise of the coal mining industry in the UK. A plausible explanation for this could be the dramatic number of instrumental stations used to contribute to the instrumental records. This peaked at 6000 in 1970, and has now dropped to less than 2000. Consider how difficult it is to ensure an accuracy sufficient to identify a 0.1 degree trend over 20 years when thermometers move and their local environment changes. Satellite readings have their own problems, but comparing the reagonal differences in trends does show that surface temperature measurements in some places give a high result.

The last decade may well have been the warmest on record (in the context of our chosen measurement scenario) but even without significant volcanic activity, the upward trend has definitely stopped. Regardless of that, weather is not becoming more extreme. The current weather in Europe is not particularly significant on a global scale, other than to emphasise that the impacts of global warming are not observable today, and should definitely not be relied upon when making forecasts or policy decisions.

Filed under Science

Comments (2)

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  1. Michael Tobis says:

    “definitely”? “stopped”?

    Do tell.

    Are you interested in a wager?

    Posted February 2, 2010 @ 8:00 pm (UK)
  2. Sean says:

    Stopped as in the observed data to date shows the past 10 years or so to have a negative trend – not in the sense of making a prediction about future trends. In the sense that IF there is any underlying upward trend, there is currently a downward variation which is masking it. In the sense that the past decade being high does not predict if it is the peak of a cycle, or the start of an exponential curve.

    Posted February 3, 2010 @ 12:33 am (UK)

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