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Scientists Cleared of Misusing Global Warming Data
Hugh Pickens writes writes "The NY Times reports that an inquiry by the Commerce Department's inspector general has found no evidence that NOAA scientists manipulated climate data (reg. may be required) to buttress evidence in support of global warming after climate change skeptics contended that e-mail messages between climate scientists that were stolen and circulated on the Internet in late 2009 showed that scientists were manipulating or withholding information to advance the theory that the earth is warming as a result of human activity. 'None of the investigations have found any evidence to question the ethics of our scientists or raise doubts about NOAA's understanding of climate change science,' says Mary Glackin, the agency's deputy undersecretary for operations. The inquiry, requested last May by Senator James M. Inhofe, Republican of Oklahoma, who has challenged the science underlying human-induced climate change, comes at a critical moment for NOAA, as some newly empowered Republican House members seek to rein in the EPA's plans to regulate greenhouse gas emissions, often contending that the science underpinning global warming is flawed. Inhofe says the report (PDF) was far from a clean bill of health for the agency, and that contrary to its executive summary, showed that the scientists 'engaged in data manipulation.'"
There really is no evidence of data 'fiddling'. NOAA makes the raw data available. They make the adjusted data available. The process they use to adjust the data (to account for relocation of weather stations/urban heat islands/etc) is also available and part of the peer reviewed literature.
A retired meteorologist named Anthony Watts did a great job of validating the robustness of the data. He (and a small army of volunteers) rated the weather stations based on how well they met requirements. Weather stations outside of urban areas and away from pavement were rated a 5. Poorly placed weather stations were rated a 1. He had hoped to find that poorly placed weather stations were responsible for the warming trend. In the end it was found that well placed weather stations actually record a greater warming trend. The reason for this may be that the warming trend of poorly placed weather stations is masked by the artificial heat in the area.
Most locations in the world are oversampled. We have high confidence in the results for those areas. Some locations such as Antarctica are under sampled. We have less confidence in the results for those areas.
Luckily we also have satellite data since 1979. The satellite data confirms the weather station data.
We have a very clear understanding of the global temperature. It's going up at a rate that is likely unprecedented over the last 1000 years.
Regarding station data errors, I have an interesting story. People used to judge the brightness of stars by eyeballing and comparing to other stars. A rating of 10 was given to the brightest stars and 1 to the dimmest. Thousands of stars were surveyed by thousands of people. The instruments used for measuring brightness (eyeballs) were very poor compared to what we use today. It was found however that the average of the eyeball results were correct to two decimal places for any given star. By oversampling you can get good results from imperfect instruments. It's also important to note that with temperatures we are only interested in the anomaly - how much did the temperature change vs the same day last year. Any station that has a systemic error of two degrees will keep the same error from one day to the next. It won't record +2 degrees one day and then -2 the next. Since we're only interested in the anomaly it doesn't really matter that it's not recording the correct temperature - only that it is consistent.