Hansen Warming Things Up In Reykjavik
By Paul Homewood
Following on from yesterday’s Icelandic Saga, I now have the real temperature records for Reykjavik from the Iceland Met Office. You will recall that GISS had recently altered their temperature records for several stations in Iceland and Greenland – full story here. Information on the Iceland Met Office site did not seem to support Hansen’s revised figures, but now I have the full temperature record for Reykjavik from them, which shows how much GISS have adjusted their temperatures up by.
The following graph compares the two temperature records from 1940 to 2007 (GISS do not have data for 2008 and 2009).
At the start of the record, both temperature sets were closely aligned, and apart from GISS upward adjustments in the 50’s, GISS adjustments were still fairly small upto about 1965. Since 1970 GISS have added on about 1C every year to the true temperature record. Interestingly the figures for 2010 and 2011 are pretty much the same, which raises the suspicion they will also be adjusted in a year or two’s time, when nobody is looking.
A good example to look at is 2003, which was the warmest year on the GISS record at 7.32C. As GISS work on a meteorological year of Dec-Nov, this would become 6.98C on a calendar basis. However the Iceland Met figure is much lower at 6.06C, only marginally higher than the 1941 temperature of 5.91C. GISS show 1941 as 5.28C.
To quantify the GISS adjustments, these are the average annual adjustments :-
1940’s + 0.49
1950’s + 0.57
1960’s + 0.63
2000’s + 0.97
In other words there is about a half a degree of artificial warming added in the last 60 years.
The Iceland Met graph seems to be a pretty close fit with the original GISS plot, showing current temperatures not dissimilar to the early 1940’s and 1960’s, and with a clear period of cooling in the 70’s and 80’s. By contrast the revised GISS graph gives a false impression of a long warming trend.
If you saw yesterday’s post, there were two other stations we looked at, Akureyri and Stykkishólmur. I also have full temperature records for these and will post in detail tomorrow, but suffice it to say, these show exactly the same false warming trends.
One thing I should point out is that the GISS figures are all “before homogenisation”, i.e. before any UHI effects have been taken out.