A particularly interesting take on this comes from Roger Pielke Sr. He wrote on July 16th:
This record event is an effective test of two hypotheses.
Hypothesis #1: Roy Spencer’s hypothesis on the role of circulation patterns in global warming (e.g. see) might explain most or all of the current anomaly since it clearly is spatially very variable, and its onset was so sudden. If the lower atmosphere cools again to its long term average or lower, this would support Roy’s viewpoint.
Hypothesis #2: Alternatively, if the large anomaly persists, it will support the claims by the
IPCC and others (e.g. see Cool Spells Normal in Warming World) that well-mixed greenhouse gas warming is the dominate climate forcing in the coming decades and is again causing global warming after the interruption of the last few years.
Only time will tell which is correct, however, we now have short term information to test the two hypotheses. The results of this real world test will certainly influence my viewpoint on climate science.
I guess the question is: how long must we wait for the results of this real world test? At this moment, it seems to be going against Mr. Spencer.