Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - General Discussion

General Climbing Discussion

Topic Date User

OT: Moorabal/Lal Lal wind farm 3-Jun-2009 At 11:06:07 AM TonyB

Message

On 2/06/2009 ajfclark wrote:
>Tony, to me the variations from the trend line on the recent 30 years
>graph looks much greater. Even the variation from the trend line within
>the the recent 30 year graph looks much greater in recent times than 20
>years ago. To me your graphs seem to indicate that the data shows destabilisation
>of the climate.

These "variations" from the trend line are less than 0.4 degrees. Remember that temperature data is recorded to the nearest 1 degree (as the average of the max and min temps), although in some places measured electronically to 0.1 degrees. Despite this, "averages" of this data are calculated and recorded to 3 decimal places ! No wonder there's fluctuations !

Over 70% of stations have errors greater than 2 degrees with 11% having a 5.0+ degree error ! http://www.surfacestations.org/ . Lots of potential for fluctuation !! Hardly anything to suggest "destabilization" ... although falling temperatures are quite apparent in one of the graphs. There is nothing to suggest anything other than natural variation and measurement error.

>Do you have any data on the standard deviations for these two data sets?
No. However this site http://www.surfacestations.org/ is carrying out an on going investigation of data veracity.

Another major issue in terms of data accuracy and variation are dramatic changes in the number of measuring stations. Add a stack of stations in the tropics and it will obviously effect the "average", even if the average is "corrected" by the IPCC's secret procedures. The number of stations fell by more than half in the late 80's, which surprise, surprise, showed a strong correlation with a rise in "average" temperature at that time. http://www.uoguelph.ca/~rmckitri/research/nvst.html

There are some quite amusing accounts of older temperature measurement, before the advent of the Stevenson screen in the late 19th century. Any data prior to 1900 should be expected to have a very large error (despite the invention of the Six thermometer more than a hundred years before).

More recent temperatures can be correlated with satellite and radiosond, which show slightly stronger recent cooling than the IPCC/Hadley data.