Anthony Watts opens mouth, places foot firmly - in the weakening Walker Circulation

As if one foot in mouth wasn't enough for the day, Anthony Watts does it again (archived here, cached here). Maybe he wanted to give both his clodhoppers a turn. Whatever - he posted one of his "claim" articles, which was about a new paper published in Geophysical Research Letters. The paper, by Katinka Bellomo and Amy C. Clement from the Rosenstiel School of Marine and Atmospheric Science, University of Miami, was describing evidence of the expected slowdown in the Walker Circulation. Beneath his "claim" headline Anthony wrote:

From the UNIVERSITY OF MIAMI ROSENSTIEL SCHOOL OF MARINE & ATMOSPHERIC SCIENCE and the “correlation is not causation department” comes this paper that suggests GHG’s decrease the Walker Circulation. Only one problem. They don’t give a clear cut mechanism, only tenuous linkage. I suspect Willis will have a thing or two to say about this paper.

Only one problem, the scientists did give a clear cut mechanism. (Actually, they referred to more than one mechanism, although they emphasised the one proposed by Isaac Held and Brian Soden.) As the authors explained right at the very beginning of their paper: