The article is a good read regarding data crunching, but I take exception to some of his methodology.
Specifically, he's only using data from 1929 and on -- this is all part of the hockey stick's head. The 1920s are supposedly the start of the dramatic temperature increase. So of course the graphs don't show a dramatic slope change; there's no pre-1929, lesser-slope data included.
Edit: I'm not implying intentional omission on his part; 1929 is the earliest year available from NOAA (ftp://ftp.ncdc.noaa.gov/pub/data/gsod).
Exactly. That's about as selective as you can get.
No way of saying that hockey stick will appear if he includes all the data but the way he filtered out the end part and then stretched it is just being very selective with the data provided.
The reason why there is so much room for interpretation in all this data crunching in part is because of the troublesome normalization issues faced when consolidating data from so many different sources.
If there had been reliable weather stations in the last two millennia this would be completely different. But obviously that's not the case.
The article is a good read regarding data crunching, but I take exception to some of his methodology.
Specifically, he's only using data from 1929 and on -- this is all part of the hockey stick's head. The 1920s are supposedly the start of the dramatic temperature increase. So of course the graphs don't show a dramatic slope change; there's no pre-1929, lesser-slope data included.
Edit: I'm not implying intentional omission on his part; 1929 is the earliest year available from NOAA (ftp://ftp.ncdc.noaa.gov/pub/data/gsod).