Tim Lambert of the weblog Deltoid writes:
USHCN station records up to 1999 were replaced by a version of USHCN data with further corrections after an adjustment computed by comparing the common 1990-1999 period of the two data sets. (We wish to thank Stephen McIntyre for bringing to our attention that such an adjustment is necessary to prevent creating an artificial jump in year 2000.)
How much difference did the adjustment make to the US temperature series? Well, it changed this:
Not much difference. The right hand end of the red curve has moved down a little bit, but this decade is still the warmest ever recorded in the US. The change to the global temperature series is imperceptible...
But Tobin Harshaw of the New York Times Opinionator writes:
Hottest Year Data Meltdown: by TOBIN HARSHAW: You just thought you were sweating? Among global warming Cassandras, the fact that 1998 was the “hottest year on record” has always been an article of faith. Stephen McIntyre, who runs the Climateaudit blog was always puzzled by some gaps he saw in the raw data provided by NASA that supported the claim (data compiled in part by James Hansen, the climate scientist who has long accused the Bush administration of trying to “silence” him). McIntyre says he has “reverse engineered” the data to find NASA’s algorithm, discovered that a Y2K bug played havoc with some of the numbers, and notified the space agency.
Michael Asher at DailyTech explains the fallout:
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 recordbreaking) 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.
The effect of the correction on global temperatures is minor (some 1-2% less warming than originally thought), but the effect on the U.S. global warming propaganda machine could be huge.
That's all Tobin Harshaw wrote.
Really sad. I don't think Tobin Harshaw looked at the data series. I don't think he could have looked at the data series and still written those paragraphs.
I don't understand why Tobin Harshaw has his current job.
UPDATE: Tobin Harshaw whines:
Note: Many commenters on this post have assumed that the author intended the term “Cassandras” to be pejorative, and also that he was unaware that the predictions made by the prophetess Cassandra, daughter of King Priam of Troy, came true. Rather, the term was being used in its common modern sense: one whose dire predictions, true or false, go unheeded.
And a few comments on Harshaw:
I just talked to someone at GISS (the group Jim Hansen heads) who said they fixed it in less than a day when they did learn about it from McIntyre (who didn’t actually “reverse engineer” anything), and when they fixed it nothing much changed. They saw a 0.15 deg C change for 2000-2006 in the US numbers (since the problem was melding the US data with the global numbers) and some very minor adjustments down the line. The global mean change was zero. 2005 was still the warmest year in the corrected GISS analysis, as it is with the NCDC analysis. Amazing what a little reporting will turn up. — Posted by Ken
This post is almost entirely incorrect. NASA’s much-ballyhooed data showing that 1998 was the warmest year on record for the Earth was right. The error was in the temperature record for the contiguous 48 states (I commend Steve McIntyre’s work), not for the global temperature record. The US temperature record has, as one would expect, a much greater interannual variability than the global record. The DailyTech article fails to point this out. I hope you will make this clear. Actually, I made a mistake. NASA’s data shows that 1998 is the second-warmest year on record for the Earth. The warmest year? 2005. The top twenty hottest years on earth since 1880: * 2005 * 1998 * 2002 * 2003 * 2006 * 2004 * 2001 * 1997 * 1995 * 1990 * 1991 * 2000 * 1999 * 1988 * 1996 * 1987 * 1983 * 1981 * 1994 * 1944 — Posted by The Cunctator
The term “hottest year on record” isn’t appropriate unless you’re talking about global climate. But you’re only talking about the lower 48 states. Why would you use such misleading language if you’re trying to educate people? By the same token, why use terms like “U.S. global warming propaganda machine” and use scare quote around the word “silence.” Hansen claimed that NASA tried to silence him, not “silence” him. If you want to discuss facts, there’s plenty to discuss. If you want to use inflammatory and misleading language that is certainly your prerogative, but aren’t there more appropriate places to do that than the New York Times? NB: Cassandra was right, remember? Her curse was to accurately predict the future but not to be believed. So calling someone a Cassandra is to imply that they are correct but unpopular. — Posted by Debra