Thursday, September 23, 2010

Australian Climate temperatures adjusted upwards by 70%

I've frequently criticized the quality of the existing climate databases, and particularly how the data is manipulated after the fact to show a higher temperature than was originally recorded.  The response of the mainstream Climate Science establishment to this is "whatever", and so it's been left to amateur "Open Source" efforts to quality control.

What they've been finding doesn't build confidence in the "hottest year of the millennium" stories we've been reading.  Not at all:
Ken Stewart has been hard at work again, this time analyzing the Australian urban records. While he expected that the cities and towns would show a larger rise than records in the country due to the Urban Heat Island Effect, what he found was that the raw records showed only a 0.4 degree rise, less than the rural records which went from a raw 0.6 to an adjusted 0.85 (a rise of 40%). What shocked him about the urban records were the adjustments… making the trend a full 70% warmer.
Computers take the raw data (the temperatures as read from the thermometers at the time) and then "homogenizes" them.  The intent of this process is to remove gaps in the record, or to eliminate sudden jumps (say, when a weather station is moved to a different location).  Fair enough.  But you simply have to question the process when the output is 70% higher than the raw data.
The largest adjustments to the raw records are cooling ones in the middle of last century. So 50 years after the measurements were recorded, officials realized they were artificially too high? Hopefully someone who knows can explain why so many thermometers were overestimating temperatures in the first half of the 1900’s.
If anything, you'd expect the thermometers to be reading too high today.  The "Urban Heat Island" effect - the fact that it's warmer in cities than in the countryside - would tend to artificially push up temperatures today, as weather stations that had been in cooler fields fifty years ago are now in a parking lot.  The SurfaceStations.org project shows that 90% of US weather stations err by more than 1° C.  Once again, the response of the mainstream Climate Science community is "whatever".

And now on top of this 80% reading hot, you can add an extra 70% from "homogenization".  How on earth could the reports not show that it's not the hottest it's been in a millennium?

And to answer Ms. Nova's question about why so many thermometers were overestimating temperature fifty years ago, that's easy.  You want more funding, you show a political problem (or opportunity).  If the data don't show the problem, you change it.

You'e welcome.

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