August 9, 2007

1998 was the warmest year on record. Not so fast...

Global Warming proponents happily point to the fact that 1998 was the warmest year on record. Unfortunately, it seems there was a bit of a bug in the data and 1998 is now the second warmest year on record and five of the ten warmest years fell before World War Two. From Daily Tech:
Blogger Finds Y2K Bug in NASA Climate Data
My earlier column this week detailed the work of a volunteer team to assess problems with US temperature data used for climate modeling. One of these people is Steve McIntyre, who operates the site climateaudit.org. While inspecting historical temperature graphs, he noticed a strange discontinuity, or "jump" in many locations, all occurring around the time of January, 2000.

These graphs were created by NASA's Reto Ruedy and James Hansen (who shot to fame when he accused the administration of trying to censor his views on climate change). Hansen refused to provide McKintyre with the algorithm used to generate graph data, so McKintyre reverse-engineered it. The result appeared to be a Y2K bug in the handling of the raw data.

McKintyre notified the pair of the bug; Ruedy replied and acknowledged the problem as an "oversight" that would be fixed in the next data refresh.

NASA has now silently released corrected figures, and the changes are truly astounding. The warmest year on record is now 1934. 1998 (long trumpeted by the media as record-breaking) moves to second place. 1921 takes third. In fact, 5 of the 10 warmest years on record now all occur before World War II. Anthony Watts has put the new data in chart form, along with a more detailed summary of the events.
Here is one example of the bad data:
Detroit_lakes_GSSplot_y2k_bug.jpg
And of course, the hue and cry from the mainstream media? *** *** *** *** *** crickets Posted by DaveH at August 9, 2007 8:57 PM