Quantitative estimate of the Milankovitch-forced contribution to observed Quaternary climate change
Abstract
A number of records commonly described as showing control of climate change by Milankovitch insolation forcing are re-examined. The fraction of the record variance attributable to orbital changes never exceeds 20%. In no case, including a tuned core, do these forcing bands explain the overall behavior of the records. At zero order, all records are consistent with stochastic models of varying complexity with a small superimposed Milankovitch response, mainly in the obliquity band. Evidence cited to support the hypothesis that the 100 Ka glacial/interglacial cycles are controlled by the quasi-periodic insolation forcing is likely indistinguishable from chance, given the small sample size and near-integer ratios of 100 Ka to the precessional periods. At the least, the stochastic background "noise" is likely to be of importance.
- Publication:
-
Quaternary Science Reviews
- Pub Date:
- May 2004
- DOI:
- 10.1016/j.quascirev.2004.02.014
- Bibcode:
- 2004QSRv...23.1001W