Comparison of CRUTEM3v Data with Raw Station Data

Comparison of CRUTEM3v data with raw station data taken from World Monthly Surface Station Climatology. On the left are the mean temperature anomalies from each pair of randomly chosen times series. On the right are the distribution of trends in those time series and their means and standard errors. (The standard error provides an estimate of how well the sampling of ~30 stations represents the full global data set assuming a Gaussian distribution.) Note that not all the trends are for identical time periods, since not all data sets are the same length. Source: http://www.realclimate.org/index.php/archives/2009/12/are-the-cru-data-suspect-an-objective-assessment/