Reply to Henriksson et al.'s comment on "Using multiple observationally-based constraints to estimate climate sensitivity" by Annan and Hargreaves (2010) RIGC/JAMSTEC, 3173-25 Showamachi, Yokohama, Japan
Received: 14 Jan 2011 – Published in Clim. Past Discuss.: 01 Feb 2011 Abstract. Henriksson et al. (2010), hereafter HALTL10, criticize Annan and Hargreaves (2006a)
(AH06) primarily on the grounds that we assumed that different sources of
data were conditionally independent given the climate sensitivity. While we
consider this approximation to have been a reasonable one under the
circumstances (and provided arguments to justify this approach), we also
acknowledged its importance in our original paper and performed several
sensitivity analyses. The alternative calculations presented by HALTL10
appear to strengthen rather than contradict our conclusion.
Revised: 26 Apr 2011 – Accepted: 03 May 2011 – Published: 09 Jun 2011
HALTL10 additionally criticize Annan and Hargreaves (2009) (AH09) for proposing a
Cauchy type prior (as an alternative to the use of a uniform prior, which was
widespread up to that time) "without sufficient support", and further claim
that anticipated economic damages were used as a means of selecting the
prior. We are surprised by these claims, especially considering that the
proposed prior was justified at some length both on the basis of both the
"Charney report" (National Research Council, 1979) and basic physical arguments, and also in
light of our elementary demonstration of the pathological failings of the
most commonly-used alternative. Thus, these claims are factually incorrect.
Citation: Annan, J. D. and Hargreaves, J. C.: Reply to Henriksson et al.'s comment on "Using multiple observationally-based constraints to estimate climate sensitivity" by Annan and Hargreaves (2010), Clim. Past, 7, 587-589, doi:10.5194/cp-7-587-2011, 2011.