The Great Thermometer Die Off
The following is from Moscow’s Paul Rumelhart. Paul has been working with temperature datasets.
I encourage you to take the time to read and digest what he writes here. This is the kind of questions that need to be asked of the AGW scientists.
Some of you know that I was at one time playing around with graphing global temperature data in order to satisfy my curiosity on a number of points related to global warming. I wish I'd stuck with it. It turns out that someone else (probably many others) has been doing the same thing. A programmer named E. M. Smith has done some work with the GISS dataset (I've been using the NCDC one). He has found that many of the measuring stations which are used for temperature reconstructions across the globe have been removed from the global temperature data sets for recent years. In fact, the data drops off quickly starting in the 80's (at least in the dataset I've been working with).
He has done some research into which stations have been removed, and has apparently found that lots of higher altitude stations have been removed, which would have shown cooler temperatures - leading to a corresponding rise in the average temperatures over the years. He has a blog which covers this (he goes by the alias "chiefio"). Here is an entry in the blog giving an overview of this topic:
http://chiefio.wordpress.com/2009/11/09/gistemp-a-human-view/
I have not tried to analyze the stations that drop off of the NCDC data set yet, perhaps I can get a little work done on that soon.
I'm also attaching a couple of graphs that I created from the NCDC data which graph the station counts by years. These are from the global minimums data sets, both normal and adjusted. I hadn't yet gotten to graphing station counts for the global means and global maximums data sets. All uniques stations and sub-stations are counted, which will mean that some sub-stations are counted twice if the thermometer is moved or something in that year. I was at one point trying to find out why these counts dropped off so quickly. It makes sense that the number of stations would increase over the years, but why the dramatic decrease in station counts? I had originally thought that perhaps there are delays in collecting data together, but 20-30 year delays? That doesn't seem plausible.
By the way, I learned of this work that E. M. Smith has been doing by watching John Coleman's hour long news special titled "Global Warming - The Other Side". You can find links to the various parts of this here:
http://wattsupwiththat.com/2010/01/14/john-colemans-hourlong-news-special-global-warming-the-other-side-now-online-all-five-parts-here/
Even I thought this video was a bit high in the sensationalist and propagandist categories, but it did cover many of the standard skeptical viewpoints that I've run into. It might be worth watching, even if you're completely convinced we're cooking ourselves with carbon dioxide.
