Glacial cycles: exogenous orbital changes vs. endogenous climate dynamics R. K. Kaufmann1 and K. Juselius2 1Department of Geography and Environment, 675 Commonwealth Avenue, Boston University, Boston, MA 02215, USA 2University of Copenhagen, Department of Economics, Øster Farimasgade 5, Building 26, 1353 Copenhagen K, Denmark
Received: 22 March 2010 – Accepted: 09 April 2010 – Published: 20 April 2010
Abstract. We use a statistical model, the
cointegrated vector autoregressive model, to assess the degree to which variations in
Earth's orbit and endogenous climate dynamics can be used to simulate
glacial cycles during the late Quaternary (390 kyr–present). To do so, we
estimate models of varying complexity and compare the accuracy of their
in-sample simulations. Results indicate that strong statistical associations
between endogenous climate variables are not
enough for statistical models to reproduce glacial cycles. Rather, changes
in solar insolation associated with changes in Earth's orbit are needed to
simulate glacial cycles accurately. Also, results suggest that
non-linear dynamics, threshold effects, and/or free oscillations may not
play an overriding role in glacial cycles.
Citation: Kaufmann, R. K. and Juselius, K.: Glacial cycles: exogenous orbital changes vs. endogenous climate dynamics, Clim. Past Discuss., 6, 585-626, doi:10.5194/cpd-6-585-2010, 2010.