The scientists who attempted to re-invent Michael Mann’s hockey stick global warming graph and were caught fudging their data have essentially admitted that their data is worthless.
This is what they say in a FAQ they have added to their paper:
Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?
A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions. [emphasis mine]
They are basically admitting that the data used to create the temperature rise of their hockey stick during the past 100 years is unreliable and therefore useless for scientific purposes. Which raises the question: Why did they publish it in the first place? See especially this analysis of this paper and the press’s reaction to it by climate scientists Roger Pielke.