Climate Sensitivity During and Between Interglacials - Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC) - page 18

Climate Sensitivity During and Between
Interglacials

Manfred Mudelsee and Gerrit Lohmann

Abstract Studying the climate dynamics of past interglacials (IGs) may help to
better assess the anthropogenically in

uenced dynamics of the current IG, the
Holocene. We select IG sections from the longest ice core archive, EPICA Dome C
(EDC), which covers the past 800 thousand years, and study as well several long,
high-resolution marine sediment records. We analyze records of Antarctic tem-
perature, radiative forcing (greenhouse gases and other factors), and sea-surface
temperature (SST). Change-point regressions inform about longer-term climate
changes and trends within IGs. Comparing trends in temperature with trends in
forcing allows inference of longer-term IG climate sensitivities. Results from many
records indicate deviations from a . IG sensitivities are

found to be comparable to estimates for the instrumental period; warming or
cooling phases during Marine Isotope Stage (MIS) 5 or 11 do not show signi

“ Holocene climate optimum ”

cant

differences in climate sensitivity.

Keywords Change points Climate sensitivity Greenhouse gases Ice cores

Marine archives Statistical time series analysis

1 Introduction

The effective climate sensitivity, S,isde ned as the change in annual surface

temperature, T, per change in radiative forcing, R. Knowledge about R is limited,
which is re

ected in an uncertain value of S. Published estimates for the time span

0.3 to 1.5 K W − 1 m 2 [Masson-Delmotte et al. ( 2013 ) and
references therein]. Analyses of temperature and forcing changes in the geologic

since 1850 range from

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