Skeptics of anthropogenic global warming (AGW) suggest that the official surface record paints a different story from the actual station records. To restore trust, should we start again with new quality control on input data in total transparency?
There is more than one “official” surface temperature record, based on actual land station records. There is the one we have developed in CRU, but there are also the series developed at NCDC and GISS. Although we all use very similar station datasets, we each employ different ways of assessing the quality of the individual series and different ways of developing gridded products. The agreement between the three series is very good.
That is because NCDC and CRU do not adjust for urbanization — even though Tom Karl, director at NCDC, suggested in a 1988 peer review paper an urban contamination of 3.73°C for a city of 5 million. Phil Jones himself, in a 2009 paper on China, found a countrywide urban contamination of 1C per century. GISS does adjust for urbanization, which results in much less U.S. warming. For the globe, their metadata base of station location/population is poor. And Steve McIntyre found they just as often adjust urban temperature trends up as down.
There is a debate over whether the Medieval Warm Period (MWP) was global or not. If it were to be conclusively shown that it was a global phenomenon, would you accept that this would undermine the premise that mean surface atmospheric temperatures during the latter part of the 20th Century were unprecedented?
There is much debate over whether the Medieval Warm Period was global in extent or not. … Of course, if the MWP was shown to be global in extent and as warm or warmer than today … then obviously the late-20th century warmth would not be unprecedented.
The Idsos at CO2 Science have done a very thorough job documenting, using the peer review literature, the existence of a global MWP. They have found data published by 804 individual scientists from 476 separate research institutions in 43 different countries supporting the global Medieval Warm Period.
Where do you draw the line on the handling of data? What is at odds with acceptable scientific practice? Do you accept that you crossed the line?
No answer. Matter for the independent review.
Anthony Watts, E.M. Smith, and I have shown in “Surface Temperature Records: Policy Driven Deception” that the surface temperature records leave a lot to be desired. Claims about global monthly and annual rankings, and that the last decade was the warmest ever, can be dismissed as folly.