My 14 year old watched it on television with us and loved it but then he is very keen on science, might be above some younger children's heads as can be a little technical if not interested. I think a summary version would be most suitable for you to show.
Perhaps too boring for 11 - 14s. Spectacular visuals, but lots and lots of Mr Stewart talking to camera and 'getting in the way'. Like a teacher! (I'm joking.) You constantly feel as if you want to look over his shoulder at the landscapes and not at his fancy anoraks / ice boots / walking boots. (Good for a sense of scale, though, sometimes.) A voiceover would have been just as good, most of the time, 'Life' style. Apologies to Iain for that. Having said that, on a recent car journey I was able to show off / bore everyone by talking them through how the yearly levels of Arctic snow, separated by a line of brown 'melted' bits like the rings of a tree (unquote), go deeper ands deeper, and harder and harder, until they turn to solid ice, so something must be going in. Next stop, that planet Blu-Ray by the academic guy with nice teeth, designer jeans and a Northern accent.