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So NASA – GISS says it does not ‘fudge’ numbers

The NASA climate tweet:

“NASA does not ‘fudge’ numbers. All data requires statistical adjustments to remove bias.”

Thanks to Ole Humlum at Climate4U we can see NASA – GISS not-fudging temperatures below. They are very active at it.

This graph shows how thermometers from 1910 still need to be adjusted, even 100 years later. They need constant correction (the bottom blue line is the month of Jan 1910). Strangely, even modern thermometers need  correction too (the top red line is January 2000).

Over the eight years since 2008, the anomaly for Jan 1910 was re-estimated in many steps to be 0.7C cooler than it was thought to be back in 2008. Meanwhile the anomaly for Jan 2000 was adjusted to be 0.09C warmer between 2008 and 2016. Presumably the original raw temperatures were already adjusted prior to 2008. Who knows?

And you thought that temperature data was just a number on a page and once a calendar year was over it was finished. How naive. Turns out it’s a fluid entity traveling through the fourth dimension. Luckily NASA GISS are able to capture the way temperatures of the past are still changing today.

NCDC adjustments to temperature

Diagram showing the adjustment made since May 2008 by the Goddard Institute for Space Studies (GISS) in anomaly values for  the months January 1910 and January 2000. See also this diagram. Last diagram update 16 April 2016.

Climate4U notes that the historic temperatures bumps and troughs are smoothed to a rising line, the “net effects of the adjustments made since May 2008 are to generate a more smoothly increasing global temperature since 1880.”

Climate Audit discusses the background for the lack of temporal stability for the GISS temperature record can be read Rewriting History, Time and Time Again.

Author Goirish, April 6, 2008

“One question that popped into my mind back then was whether or not – with all of the estimation going on – the historical record was static. One could reasonably expect that the record is static. After all, once an estimate for a given year is calculated there is no reason to change it, correct? That would be true if your estimate did not rely on new data added to the record, in particular temperatures collected at a future date. But in the case of GISStemp, this is exactly what is done.

On March 29 I downloaded the GLB.Ts.txt file from GISS and compared it to a copy I had from late August 2007. I was surprised to find several hundred differences in monthly temperature. Intrigued, I decided to take a trip back in time via the “Way Back Machine”.

Here I found 32 versions of GLB.Ts.txt going back to September 24, 2005. I was a bit disappointed the record did not go back further, but was later surprised at how many historical changes can occur in a brief 2 1/2 years.The first thing I did was eliminate versions where no changes to the data were made.

On average 20% of the historical record was modified 16 times in the last 2 1/2 years. The largest single jump was 0.27 C. This occurred between the Oct 13, 2006 and Jan 15, 2007 records when Aug 2006 changed from an anomoly of +0.43C to +0.70C, a change of nearly 68%.


See also How much Estimation is too much Estimation?

They haven’t got a space shuttle and cannot fly a rocket without Russian engines anymore, but NASA can bendy-the-space-time-continuii to measure temperatures today back in 1910.

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