Other production partners are the Discovery Channel Canada, ZDF (Germany), Antena 3 (Spain) and Skai TV (Greece). The production team, which includes executive producer Alastair Fothergill and series producer Vanessa Berlowitz, were previously responsible for the award-winning series The Blue Planet (2001) and Planet Earth (2006), and Frozen Planet is billed as a sequel of sorts. David Attenborough returns as narrator, and the series was shot entirely in HD. The seven-part series focuses on life and the environment in both the Arctic and Antarctic. The production team were keen to film a comprehensive record of the natural history of the polar regions, because climate change is affecting landforms such as glaciers, ice shelves, and the extent of sea ice.