The general impression one gets from the popular press is that over the last few years there has been accelerated global warming from the elevated levels of atmospheric carbon dioxide. In fact global warming has stalled since 1998.
But there was warming during the early part of the 20th Century, and the rate of warming then was almost identical to the rate of warming at the end of the century.
"Without getting into details (ask questions in comments if you have them), using HadCRUTv3 the rate of change during the early part of the 20th century was almost identical to the rate of change at the end of the century. Could there be some sense in which the warming at the end of the 20th century was a repeat of the pattern seen in the earlier part of the century? Since the rate of increase in greenhouse gas emissions was much lower in the earlier part of the century, what could possibly explain why temperatures increased for so long during that period at a rate comparable to that experienced during the recent warming?
Read more here: http://wattsupwiththat.wordpress.com/2008/03/26/evidence-of-a-significant-solar-imprint-in-annual-globally-averaged-temperature-trends-part-1/
Or if it is a derivative (in the lower panel), it's not called one...it's called "cyclicality". Also the text (inset upper panel) gives rates of change of long periods of time from the SMOOTHED graph. Is the cyclicality (derivative?) done on smoothed or raw data? For instance from 1980 to 2000, the slope is positive (smoothed). And even if derivative of raw data taken (which will be more sawtoothy), will still see by averaging, that it tends to be more positive than negative (has to be...given the endpoints).
Jen, what do you mean when you say you find the second graph compelling? There's actually one figure with two graphs and with some text on the first graph for rates of change of different periods. The whole exposition confused me for a bit. The bottom panel is not a derivative. If we wanted to make comments about rates of change over time, plotting the derivative would be helpful. But that cyclicality panel is measuring "cyclicality", whatever that means. And it seems like the "cyclicality" is not consistent either. (I intuit that this HURTS Watts's point of suncycles actually.)
Anthony Watts comes up against some data he didn't like.
SJT must have come up against something he didn't like we haven't seen an answer. What was is I wonder.
"Haven't heard about his Stevenson screens paint job for a while now."
Wrong!!!!
http://wattsupwiththat.wordpress.com/?s=Screen+paint+test
SJT: "Haven't heard about his Stevenson screens paint job for a while now."
What is your point exactly?