The article starts:

From the told ya so department, comes this recently presented paper at the European Geosciences Union meeting. Authors Steirou and Koutsoyiannis, after taking homogenization errors into account find global warming over the past century was only about one-half [0.42°C] of that claimed by the IPCC [0.7-0.8°C].

However, from the article inflation department, that isn't the whole story.  This was a conference contribution based on a graduation thesis which was submitted to the EGU session "Climate, Hydrology and Water Infrastructure". The abstracts are not peer-reviewed and most of Watts's data was taken from the slides which are also not peer-reviewed. And it was presented in the wrongs session as there was actually a session on Homogenization of data. One of the climate scientists, who noted the paper had errors commented, :" I have never seen an abstract that was rejected at EGU; rejection rates are in the order of a few percent and these are typically empty or double abstracts and are due to technical problems during submission. It would have been better if this abstract was sent to the homogenisation session at EGU. This would have fitted much better to the topic and would have allowed for a more objective appraisal of this work. Had I been EGU convener of the homogenization session, I would probably have accepted the abstract, but given it a poster because the errors signal inexperience with the topic and I would have talked to them at the poster."

That about sums it up.