Mann-Made Warming In The Arctic
By Paul Homewood
Claims of “hottest evah” months are heavily dependent on much higher temperatures than usual in the Arctic. However, there is a big problem here, because there is very little actual data above the Arctic Circle, as NOAA admit below.
To get around this problem, GISS guess temperatures, based on stations up to 1200 km away.
The results GISS get from this, however, bear no resemblance to DMI’s calculation of Arctic temperatures, which are currently running close to the average (1958 to 2002).
There is a very good reason for this difference. The handful of temperature records that GISS have mainly tend to be coastal sites, and are therefore heavily influenced by maritime conditions. Less ice offshore, or a warm current from the south, can have a big effect on temperatures there.
These conditions don’t apply inland. Furthermore, it is well known that the temperature of air over sea ice tends not to rise much above freezing. The reason is that as the ice melts it draws heat from the air above it.
This effect can be clearly seen on any of the DMI charts during the summer months. For instance, in 1958 which was the first year recorded.
Pick any year, and you will find pretty much the same pattern, with actual temperatures closely following the green average line, barely above freezing.
If we look at the annual numbers, we find that, according to GISS, temperatures in the Arctic have been rising at a rate of 0.52C/decade since 1979.
Yet in comparison, UAH atmospheric temperatures have risen by less than half as much over the same period, 0.21C/decade.
RSS numbers tend to agree with UAH, though are slightly higher as they don’t go above 82N.
It is hard not to conclude that GISS are grossly overestimating Arctic temperatures.