Does global warming diminish with accurate temperature measurements? Part 2

July 6, 10:45 AMSF Environmental Policy ExaminerThomas Fuller

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Who can we trust when we start talking about temperatures and global warming? I wrote yesterday that there seem to be significant problems with the U.S. data set. But how about the rest of the planet?

Temperatures started climbing when we exited the Little Ice Age in the late 1800s. But this didn't become a matter of international concern until the rapid rise that occurred between 1975 and 1998. However, the way we have measured temperatures has changed along with the temperature.

The main global surface temperature data set is managed by the US National Oceanic and Atmospheric Administration (NOAA) at the National Climatic Data Center (NCDC). This is the Global Historical Climate Network (GHCN). This data is analysed by three main research organisations, each of whom use the same data and do different things with it--NASA's Goddard Institute for Space Studies (GISS), the UK-based Climatic Research Unit of the University of East Anglia (HadCRU), and the NOAA NCDC (National Oceanic and Atmospheric Administration National Climatic Data Center). 

In 1975, almost 75% of land temperature measurement stations were outside the U.S. Now, for a variety of reasons (the fall of the Soviets being chief among them), U.S. stations now make up 51% of the total. So yesterday's article detailing issues with U.S. surface temperature measurements becomes more important. If our numbers are wrong, it would be difficult for even perfect measurements elsewhere to overcome any bias we introduce into the system.

Sadly the rise in temperatures correlates with the fall in the number of measurement stations. But it gets even more difficult.

After temperatures are collected from the various stations, a series of adjustments is performed on the data. This is absolutely necessary, and it definitely does not mean that people are playing tricks with the data. They have to correct for time of observation, changes in station equipment, station history and urban warming. But while the data collected for U.S. stations is available for examination, the dataset used by the IPCC is not. The numbers they use come out of a 'black box,' and there's a story behind that which I won't go into today. The global measurements for the three teams analysing the same data is not very different, but the fact that global warming as measured to date is almost exactly equal to the adjustments performed to the data makes some sensible people queasy, and is red meat to those who are most skeptical--you can easily imagine the press release headline that would set people off.

And if there are documented problems with U.S. surface stations, as noted by Anthony Watts and his band of volunteers, and if bad data is adjusted by the same people who are not paying attention to Watts' measurements, the political problems get worse. There are also some silly games being played, such as starting measurements in a particular year because they make the situation look worse. But apparently just about everybody does that on both sides of this issue.

And if the U.S. is having problems making the system work, it is reasonable to expect that other countries might experience problems, too. And lastly, the fall in the overall number of stations is troubling, especially as warming increases at the same time numbers are cut.

So I'll repeat my call for real action on climate change--let's make some measurements that everybody trusts so we can actually have confidence in the scope of the problem.