«Recently, Abreu et al. (2012, hereafter A2012) made a new attempt in this direction by comparing periodicities detected in the records of cosmogenic isotopes 10Be and 14C (or quantities derived from them) as proxies for solar activity in the past 9400 years with those of the torque exerted on a thin shell of an ellipsoidally deformed Sun.» (landscheidt.info)
For the reconstruction into the past this amplitude is scaled with proxies for the solar activity. (aanda.org)
(see Part 1 of the Link) The way to go is simply to state clearly what the working hypothesis is and what are the reasonable assumptions that went into them — in my case the basic assumptions are that the current warming peak is a synchronous peak in the 60 and 960 year periodicities and that the 10Be and neutron count records are the best proxy for solar activity. (realclimate.org)