  Callebaut et al. (2012)'s claim that Scafetta (2010)'s results about a
correlation between 20-year and 60-year temperature cycles and the orbital
motion of Jupiter and Saturn were not confirmed by Humlum et al. (2011) is
erroneous and severely misleading. Also Callebaut et al. (2012)'s absolute
claim that a planetary influences on the Sun should be ruled out as a possible
cause of solar variability is not conclusive because: (1) their calculations
are based on simplistic classical Newtonian analytical mechanics that does not
fully characterize solar physics; (2) the planetary theory of solar variation
is supported by empirical findings. We show that both claims are already
questioned in the scientific literature.
