FAKING THE FIGURES
I just came across this statement in the NCDC website
"NOTE: From February 2006 through April 14, 2006, the anomalies provided from the links below were inadvertently provided as departures from the 1961-1990 average. Anomalies are now provided as departures from the 20th century average (1901-2000)."
You will be aware that the "global average surface temperature record", quoted so frequently by the IPCC, consists of annual "anomalies" which are the mean annual figure of temperatures in 5ºx5º latitude/longitude gridboxes, from which this 1901-2000 average is subtracted.
Now, maybe they were able to calculate an average for the year 2000 from 1,600 stations and 500 gridboxes and in the year 1901 they had 1,600 stations and 300 gridboxes.
It sounds comparable; but the world was a very different place in the year1901 from the year 2000. The total number of possible 5ºx5º gridboxes is 2592, so, even today, they only cover 20% of the earth, and mostly near cities. It was actually better in the year 1985 when there were 6000 stations and nearly 900 gridboxes. Many have been closed down since then. mostly in rural areas where the results are less contaminated by urban heating.
In the year 1901, Antarctica, Central Africa and South America, and most of Siberia had no weather stations. Figures for the oceans were minimal and most of the stations were in the Northern Hemisphere. It might be mentioned that there have never been readings near the North Pole because the Arctic is an ocean yet they keep telling us it is getting warmer
In 1901 thermometers were graduated in intervals of one degree Fahrenheit and the standard of the equipment, shelters. supervision were very different from today.They are subtracting figures which have completely different origins. The error in doing this is likely to exceed the supposed 0.7ºC which "anomalies" from 1901 are supposed to have increased
Recently NIWA made a big fuss claiming that most New Zealand glaciers are receding because of "global warming"
Nobody has ever measured the temperature over a glacier so there is no evidence of a possible increase. However, NIWA have a measurement station at Mount Cook, and they do not tell us whether the temperature there is rising or falling. Since the rest of New Zealand is cooling and has the best ski season for years I am willing to bet that Mount Cook, and all the glaciers are falling in temperature as well.
A Recent paper in Geophysical Research Letters provides useful guidance. M C Pepin, J D Lundquist, GRL 2008 35, L14701 doi 1029/2008GL034020 "Temperature Trends at High Altitude over Tropics" chooses temperature records from high altitude weather stations and plots the average trend over recent years, which is slightly downwards, as are the general trends. Only a few urban stations show a rise. So the glaciers are unlikely to be receding because of "warming" after all.