One can see (in a research summary below) how mistakes can and have been made in estimates of sea ice cover in the Arctic. People often quickly latch onto a first media report, (for example that Arctic sea ice is increasing) and make broad assumptions from that... then do not follow up on later research. In this case, further research shows that information from satellites were giving false readings. This often fuels comspiracy theories.

The perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009:
In situ observations from CCGS Amundsen indicate that the MY sea icescape in the southern Beaufort Sea was not as ubiquitous as it appeared in satellite remote sensing (Figure 1) in early September 2009. A large sector of what was remotely sensed to be MY sea ice at 7 to 9 tenths ice cover, consisting primarily of large to vast MY ice floes, was in fact a surface of heavily decayed ice composed of some small MY floes (1 tenth) interspersed in a cover dominated by heavily decayed FY floes (4 tenths) and overlain by new sea ice in areas of negative freeboard and in open water between floes. In some areas (e.g., stations L1 and MYI: Figure 1) the ocean surface was dominated in some areas by MY sea ice that was much thicker than the heavily decayed FY sea ice previously discussed. This case of mistaken identity is physically explained by the factors which contribute to the return to Radarsat-1 from the two surfaces; both ice regimes had similar temperature and salinity profiles in the near-surface volume, both ice types existed with a similar amount of open water between and within the floes, and finally both ice regimes were overlain by similar, recently formed new sea ice in areas of negative freeboard and in open water areas. The fact that these two very different ice regimes could not be differentiated using Radarsat-1 data or in situ C-band scatterometer or microwave radiometer measurements, has significant implications for climate studies

and for marine vessel navigation in the Canada Basin. The results also suggest that operational agencies (such as the CIS) should consider making ice decay a variable in their ice charts. The presence of this rotten ice regime in the centre and western limit of the Beaufort pack ice allows for wind generated swells to penetrate far into the last remaining MY ice along the Canadian Archipelago further weakening the continuity of the MY pack (Asplin et al. 2010). Our results are consistent with ice age estimates (Fowler and Maslanik, http://nsidc.org/news/press/20091005_minimumpr.html) that show the amount of MY sea ice in the northern hemisphere was the lowest on record in 2009 suggesting that MY sea ice continues to diminish rapidly in the Canada Basin even thought 2009 aerial extent increased over that of 2007 and 2008.

(David G. Barber1, Ryan Galley1, Matthew G. Asplin1, Roger De Abreu4, Kerri-Ann Warner1, Monika Puæko1,2, Mukesh Gupta1, Simon Prinsenberg3, Stéphane Julien, Centre for Earth Observation Science, Faculty of Environment, Earth and Resources, University of Manitoba, Winnipeg, MB, Canada)