Analysis of sea ice parameters for the Eurasian Arctic during the IPY, based on polar stations and satellites data, showed later ice formation, slower growth, reduced fast ice area and earlier ice disappearance though a trend towards earlier ice formation was noted for the past two years. Analysis for the Arctic Ocean showed a September 2007 ice extent minimum for the whole observational period while by September 2009 the ice extent increased by 0.8-0.9 million km2. Analysis of seasonal variations for 1978-2009, showed that the extreme changes in 2007 were mostly for the Laptev – Chukchi Seas with extrema in other years for other sectors.

Based on ice charts, relatively long-term trends with cyclical fluctuations of smaller time scales have been identified for the Arctic sea ice cover during XX-beginning of XXI centuries. Comparison of ice charts data with passive microwave for 1978 – 2009, shows their chronological correlation for studying past climate variability.

Analysis of Antarctic data showed continuation of ice cover extension during the IPY with maximum yearly averaged Antarctic ice extent in 2008, exceeding the Arctic by about 0.5 million km2. Joint analysis of satellite, shipborne and station data also demonstrates a general complication of ice conditions for Antarctic navigation.

Pronounced opposite trends in the Antarctic and Arctic in the yearly averaged ice extent during the 1978-2009 point to opposite climatic changes in these regions, question the "global warming" and indicate an influence of natural causes. Direct mechanism for sea ice climate variability is likely due to changes in the zonal flows in the atmosphere of the mid and high latitudes, which in turn is associated with changes in the state of polar vortex. Deepening of the vortices is accompanied by warming, and filling – by cooling over larger areas of Polar Regions.