“AMO+PDO= temperature variation – one graph says it all“. If you’ve got a high-school science project, the “Science and Public Policy” Institute has a laser printer! Anthony Watts is eager to tell us about the latest final nail in the coffin of AGW from retired meteorologist Joe D’Aleo and geologist Don Easterbrook. Our hopeful contestants present Multidecadal Tendencies in ENSO and Global Temperatures Related to Multidecadal Oscillations. They’ve managed to force the US Mean Temperature to look like it’s a near-perfect match for ocean circulation patterns! Global Warming is dead! And it’s natural. Although they do admit that there is “some departure after around 2000.”
How did they see what no-one else could? Well they chose their time period carefully so they could exclude the last ten years of warming that oppose the natural patterns. Then they smoothed the heck out of the data to artificially inflate the confidence of their results. Of course the AMO (detrended North Atlantic SST anomalies) and PDO (principal component analysis North Pacific SST anomalies, north of 20N) are incompatible values, so we have to wonder why they are combined. One graph does indeed say it all…
Of course, even if their claim withstood examination they still would have only found a correlation. Are the ocean circulation patterns driving air temperature, or vice versa, or is something else driving both? Joe and Don are silent on this interesting subject. Can you say anti-science?
Climatologists have no problem observing natural patterns in historical temperature data and proxies. They just also know that the recent global temperature increases do not follow any of these natural patterns.
I actually thought the discussion in the comments was quite good and people took that paper apart fairly readily. Maybe it’s because there’s such a large contingent of WUWT commenters who follow D’Aleo and bring up the PDO in pretty much every discussion.
It’s a good example of where WUWT could be as a “science site” if it wanted to be.
[Yes, a hint of what could be. But you’d think that Anthony would aspire to inform his readers, not be informed by them. He’d much rather continue to post disproved claims that “it’s natural!” and slide away from them if he’s caught out. – Ben]
Watts’ mission appears to have become no more than the spreading of confusion, trying to prove there is no consensus at all in this way, trying to prove one comment about climate change is as good as any next even if opposite.