Last week a report in Nature sought to undermine the case of the global-warming-deniers. Although there are certainly observations that suggest that, especially during the nineties the world was mostly warming up, the exception has always been Antarctica. The BBC continues to broadcast archive footage of great sheets of ice falling from Antarctica into the sea, without emphasizing that this is a particular area of the Peninsular that reaches up towards South America near to which volcanic activity is taking place undersea. It is a case of a picture being more powerful than 1000 words. In fact The vast mass of Antarctica, all satellite evidence has shown, has been getting colder over the past 30 years. Last year's sea-ice cover was 30 per cent above average.
The new paper from Eric Steig 'demonstrates' that Western Antarctica has also been warming up. At the moment I am reading a book by Ben Goldacre called 'Bad Science' in which the junior doctor and Guardian columnist takes apart the quack nutritionists and other perpetrators of media fraud, so I have my nonsense antennae primed. My suspicions are further raised when I see that one of Steig's co-workers is Michael Mann inventor of the notorious 'hockey stick' graph that has been so disparaged. So we need to examine the data.
It turns out that the data were produced by a computer model based on combining the satellite evidence since 1979 with temperature readings from surface weather stations. The problem is that there are very few surface weather stations, and those that there are are predominately on the warmer peninsular. Even arch-warmist Dr Kevin Trenberth expressed some surprise. He wryly observed "it is hard to make data where none exists". But perhaps the most telling comment comes in a letter sent to Steig by Ross Hays, an atmospheric scientist who has often visited the Antarctic for NASA.
Let me first say that this is my own opinion and does not represent the agency I work for. I feel your study is absolutely wrong.
There are very few stations in Antarctica to begin with and only a hand full with 50 years of data. Satellite data is just approaching thirty years of available information. In my experience as a day to day forecaster that has to travel and do field work in Antarctica the summer seasons have been getting colder. In the late 1980s helicopters were used to take our personnel to Williams Field from McMurdo Station due to the annual receding of the Ross Ice Shelf, but in the past few years the thaw has been limited and vehicles can continue to make the transition and drive on the ice. One climate note to pass along is December 2006 was the coldest December ever for McMurdo Station. In a synoptic perspective the cooler sea surface temperatures have kept the maritime storms farther offshore in the summer season and the colder more dense air has rolled from the South Pole to the ice shelf.
There was a paper presented at the AMS Conference in New Orleans last year noting over 70% of the continent was cooling due to the ozone hole. We launch balloons into the stratosphere and the anticyclone that develops over the South Pole has been displaced and slow to establish itself over the past five seasons. The pattern in the troposphere has reflected this trend with more maritime (warmer) air around the Antarctic Peninsula which is also where most of the automated weather stations are located for West Antarctica which will give you the average warmer readings and skew the data for all of West Antarctica.
With statistics you can make numbers go to almost any conclusion you want. It saddens me to see members of the scientific community do this for media coverage.
The link is to an anti-global warming site so it has to be handled with care, but as someone with no expertise in climate science, but with a healthy scepticism about scientists, I conclude that the anthropogenic global warming case is not proven