Paleoglaciologys Grand Unsolved Problem

The paleoglaciological concept that during the Pleistocene glacial hemi-cycles a super-large, structurally complex ice sheet developed in the Arctic and behaved as a single dynamic system, as the Antarctic ice sheet does today, has not yet been subjected to concerted studies designed to test the predictions of this concept. Yet, it may hold the keys to solutions of major problems of paleoglaciology, to understanding climate and sea-level changes. The Russian Arctic is the least-known region exposed to paleoglaciation by a hypothetical Arctic ice sheet but now it is more open to testing the concept. Implementation of these tests is a challenging task, as the region is extensive and the available data are controversial. Well-planned and coordinated field projects are needed today, as well as broad discussion of the known evidence, existing interpretations and new field results. Here we present the known evidence for paleoglaciation of the Russian Arctic continental shelf and reconstruct possible marine ice sheets that could have produced that evidence.

Possible Effects of Anthropogenically-Increased CO2 on the Dynamics of Climate: Implications for Ice-Age Cycles

A dynamical model, developed to account for the observed major variations of global ice mass and atmospheric CO2 during the late Cenozoic, is used to provide a quantitative demonstration of the possibility that the anthropogenically-forced increase of atmospheric CO2, if maintained over a long period of time (perhaps by tectonic forcing), could displace the climatic system from an unstable regime of oscillating ice ages into a more stable regime representative of the pre-Pleistocene. This stable regime is characterized by orbitally-forced oscillations that are of much weaker amplitude than prevailed during the Pleistocene.