Proponents of the anthropogenic global warming theory rely on global temperature data over a period of centuries that purport to be accurate to within a tiny fraction of one degree. Common sense warns us to be skeptical of such spurious certainty. But the truth is much worse: climate alarmists have systematically fudged the historical record by changing past temperature data to make it look as though the earth is warming, consistent with their theory.
We have written about this before; the latest comes from Watts Up With That, the world’s most widely read web site on climate science:
I ran a post yesterday, showing how the latest version of GISSTEMP had changed from using Hadley/Reynolds to ERSST for ocean temperatures, with the result that about 0.03C had been added to recent warming.
However, this is not the only change they have made to the historical temperature record in recent years. Climate4You, fortunately, archived the GISS data in May 2008. Comparing this dataset with today’s version, we can see that about 0.10C of warming, or more, has been added to temperatures in the last decade, compared to data up to about 1950.
GISS is NASA’s Goddard Institute for Space Studies, which was commandeered some years ago by global warming hysteric James Hansen. Its data are widely relied on to support claims of unprecedented warming. But GISS has been playing games with the historical record, changing previously reported temperatures going all the way back to the 19th century. They don’t acknowledge doing this, they just change the data retroactively. This chart shows the changes that have been made since 2008. Generally, GISS lowered the temperatures from the 1890s until approximately the 1960, and then increased the previously-reported temperatures starting in the 1970s. Their purpose, obviously, is to manufacture an apparent warming trend above and beyond the temperatures that were actually reported at the time:
Other changes in the data had been made prior to 2008, as well; these changes also had the effect of magnifying alleged warming. Shockingly, one-quarter of the global warming that GISS alleges has taken place during the 20th century is due to these falsifications–let’s be polite and call them revisions–to the data.
So any time anyone wants to debate global warming, the first point to be made is that the data created by GISS and similar organizations are corrupt and unreliable.