http://joannenova.com.au/2010/07/did-giss-discover-30-more-land-in-the-northern-hemishphere/ Frank Lansner has been tinkering with the NASA GISS dataset – trying to understand how it works, or rather, how arch AGW adherent James Hansen gets his numbers. The northern hemisphere has a ratio of 40 per cent land to 60 pere cent ocean, which is used by Hadley CRU in the UK (HadCRU at UEA). However, Lansner has discovered the GISS dataset is more land based than ocean sensitive (temperature) and is actually weighted to nearly 70 per cent land and only 30 per cent ocean. The balance of ratio appears to have changed sometime between 1995 and 1999, he continues, and Lansner is puzzled and asks the help of others on the blogosphere in order to find out what has happened. Joanne makes the point that if there were more positions for scientists who were interested in finding other causes of warming (other than greenhouse ones) these kinds of questions would have been settled years ago and would not be left to volunteers such as Lansner, and retirees. It may be that NASA GISS adjustments are justifiable – but who knows? Climate scientists work in a small exclusive vacuum apparently, a small bubble that excludes everyone but them. As an example, one of them has recently objected to the meteorologist Joe Bastardi commenting on climate – why should anyone ask a weather man about climate, he is reported to have said. The problem is that all the adjustments raise the level of warming, which suggests they may very well be convinced warming is taking place and are nudging the numbers to make that appear as fact on their projections and graphs. Who knows? However, in spite of the tinkering with data-sets by all the climate science facilities Mother Nature may not respond to the theory – that is what Joe Bastardi says (and he is a weather man).
A reponse came – see ned of post. It was said that GISS adjusts temperature to their griddded product (criticised last year by Watts and D’Aleo). They use thermometer readings for land to adjust sea surface temperatures up to 1200km out to sea (as Watts and D’Aleo discovered). The warm temperatures that are supposed to be taking place in the Arctic are actually being derived from land measurements around the Arctic. In contrast HadCRU does not extrapolate Arctic temperature – they leave it blank. The results are the same, or nearly so. The problem is that sea surface temperatures are not available in the Arctic when it is covered by ice – for most of the year.
The next day the same story is posted at http://wattsupwiththat.com July 18th – the Lansner study, and a post by Bob Tisdale which explains the latter, above. This update is probably the best read.