Skipping over the fact that they've ignored the last 8 years of cooling and only taken up to 2005, this data is: A "bias-corrected" data set based data simulate

Skipping over the fact that they've ignored the last 8 years of cooling and only taken up to 2005, this data is: A "bias-corrected" data set based data simulated from some models, where the bias-correction algorithm is the result of a study which uses a model-derived data set as it's input, where this model-derived data set is itself derived from another model-derived data set, which is calibrated against "psuedo-observations", and I haven't even bothered to look what model they based that on. I'd say it's about as reliable as a Microsoft operating system.