That's actually a pretty wide range. But does it refute any sort of consensus? I looked up what the AR4 had to say. There wasn't much, but in Chap 7, sec 220.127.116.11, I found this:
“A 1°C increase in sea surface temperature produces an increase in pCO2 of 6.9 to 10.2 ppm after 100 to 1,000 years (Heinze et al., 2003; see also Broecker and Peng, 1986; Plattner et al., 2001). “
That seems quite within the range Frank et al find. Yet people who suggest some pillar of AGW has fallen say that recent estimates were up to 40 ppmv/C. Lubos Motl had cited that figure, so I put the IPCC figure to him. He cited this 2006 paper by Scheffer, Brovkin and Cox as the source of the 40 ppmv/C claim.
I looked up that paper. They had deduced their estimate from the CO2 response to the LIA, and said
we arrive at an estimated carbon sensitivity (Î±) to temperature of 41 (following Mann and Jones) to 12 (following Moberg et al) ppmv CO2°C.
A rather ambivalent figure to be refuting.