Editor's Note: Alastair Fothergill, Frozen Planet Executive Producer, writes for the About the BBC blog about his experience on working on Frozen Planet.Frozen Planet has just finished broadcasting on BBC One, and although we have only had the final figures for the first four episodes, we know they have attracted an average weekly audience of 12 million viewers. These viewing figures even surpassed those for Planet Earth that broadcast back in 2006 in a very different broadcasting market. The audience appreciation index of 94 out of a 100 broke all previous records for any series on the BBC. So many people of all ages have told us how much they have really enjoyed the series. For the whole team that worked on Frozen Planet, it has been a very satisfying end to a long production journey.

I have been fortunate to work on a number of landmark natural history series for the BBC Natural History Unit including The Blue Planet and Planet Earth, but Frozen Planet was definitely the most ch