Soren wrote on Aug 6
th, 2012 at 11:26am:
This just in:
You've been missing the discussion on Watts on another thread. In a nut shell, he made a great many incorrect assumptions and failed to grasp the basic principles. Of course, that's not entirely unexpected for a layman.
Did you miss this part, where the maximum possible effect of adjustments was discussed?
Quote:Adjustments Make Little Difference Globally
While Watts et al. identify possible issues concerning the adjustments applied to station temperature records, it wisely makes no attempt to assess the global impact of the adjustments, which are beyond the scope of the work. Nonetheless, this is a significant question from a public interest perspective.
In order to answer this question, we willl try and estimate the maximum possible impact of station adjustments on the instrumental temperature record. To minimise the warming signal, we will use the simplest method for calculating a global temperature average - the CRU method, which is known to yield poor coverage at high latitudes and hence underestimate recent warming. Further, we'll assume that entirety of the data adjustments are wrong (ignoring proven bias corrections such as TOB). If we calculate land temperature averages from both the raw and adjusted data, we can see how much difference the adjustments make. The result is shown in the figure below (red and green lines).
In fact the adjustments make
very little difference anyway.