Paleoclimate proxy data is essential to broaden our understanding of climate variability. There remains however challenges for traditional methods of variability analysis to be applied to such data which is usually irregular. We perform a comparative analysis of different methods of scaling analysis, which provide variability estimates as a function of timescales, applied to irregular paleoclimate proxy data.

Based upon research results over the past five decades, there is a general acceptance that the ice ages were produced by astronomical phenomenon as theorized by Milutin Milankovitch. However, unresolved contradictions between the empirical findings and theory remain. Several theory modifications show how Earth's eccentricity provides conditions for global glaciation. Global glaciation including colder winter glaciation resolves the contradictions addressed including the 100,000 year problem.