On the Milankovitch sensitivity of the Quaternary deep-sea record 1Geosciences Research Division, Scripps Institution of Oceanography, University of California, San Diego, USA
21 Aug 2013
*Invited contribution by W. H. Berger, recipient of the Milutin Milankovic Medal 2012.
Received: 11 January 2013 – Published in Clim. Past Discuss.: 04 March 2013 Abstract. The response of the climate system to external forcing (that is, global
warming) has become an item of prime interest, especially with respect to
the rate of melting of land-based ice masses. The deep-sea record of ice-age
climate change has been useful in assessing the sensitivity of the climate
system to a different type of forcing; that is, to orbital forcing, which is
well known for the last several million years. The expectation is that the
response to one type of forcing will yield information about the likely
response to other types of forcing. When comparing response and orbital
forcing, one finds that sensitivity to this type of forcing varies greatly
through time, evidently in dependence on the state of the system and the
associated readiness of the system for change. The changing stability of ice
masses is here presumed to be the chief underlying cause for the changing
state of the system. A buildup of vulnerable ice masses within the latest
Tertiary, when going into the ice ages, is thus here conjectured to cause a
stepwise increase of climate variability since the early Pliocene.
Revised: 19 June 2013 – Accepted: 15 July 2013 – Published: 21 August 2013
Citation: Berger, W. H.: On the Milankovitch sensitivity of the Quaternary deep-sea record, Clim. Past, 9, 2003-2011, doi:10.5194/cp-9-2003-2013, 2013.