A framework for interpreting paleoclimatic variations in Eastern Beringia

Abstract Paleoclimatic variations in a particular region can be viewed as the outcome of the superimposition of the effects of a number of large-scale controls. A framework for understanding paleoclimatic variations in a region can be established by considering the long-term history of those controls jointly with climatic modeling results that illustrate how regional climates respond to changes of individual controls. The relevant controls of Late-Quaternary paleoclimatic variations in eastern Beringia include: (1) the size of the ice sheet, which influences both atmospheric circulation and temperature, (2) insolation, which influences mainly temperature and seasonality, (3) carbon dioxide concentration in the atmosphere, which influences temperature, and (4) feedbacks involving sea ice, sea-surface temperatures and snow cover, which reinforce the insolation effects. We review the results of a number of ‘paleoclimatic experiments’ with general circulation models to illustrate the potential response of eastern Beringia to the variations of these controls. We then present a framework for understanding paleoclimatic variations in eastern Beringia by describing the likely responses of the climate of this region to the known variations in the controls. In addition, we discuss key times during the Quaternary when particular combinations of the controls give rise to ‘natural experiments’ which lend themselves to the testing of particular hypotheses. Our understanding of the nature of climatic variations at high latitudes should increase through examination of paleoclimatic evidence that documents the response of the region at those key times.