A reply to the critical evaluation of the Oscillayers methods and dataset

The authors offered a critical evaluation of theory and methods of the
Oscillayers approach and attempted to test its utility by reproducing
global circulation model (GCM-)based palaeo-climatic reconstructions of
two variables (Bio1 and Bio12) for four different time points (130kyr,
787kyr, 3.2Myr, 3.3Myr). They concluded that Oscillayers show poor
agreement with independent GCMs and thus do not provide a robust
approximation of palaeoclimate throughout the Plio-Pleistocene. Here, I
demonstrate that the authors underestimated the ability of Oscillayers to
reproduce independent GCMs by not taking into account inter-framework
differences between the models used to generate the Oscillayers and
PaleoClim datasets. However, upon correcting this systematic error,
differences in Bio1 and Bio12 between Oscillayers and PaleoClim GCMs are
less than ± 1°C or ± 50 mm on average in 35.9% (range: 11.8 – 59.0%) or
46.7% (20.8 – 66.0%) of values, respectively. Thus the agreement between
Oscillayers and PaleoClim is on average c. 1.5 to 2 times higher than
estimated by the authors and mostly well above the inter-model agreement
between two commonly used GCMs (CCSM, MIROC) for the Last Glacial Maximum
(LGM). Consequently, I conclude that the Oscillayers approach does provide
reasonably robust approximations of palaeo-climate throughout the
Plio‐Pleistocene. Some clarifications are given.