The thing that makes this documentary so inspiring is that it is not a lecture. Sir David Attenborough demonstrates through his wealth of experience over the years, the chronology of the decline of the natural world without preaching to us. The beautiful imagery accumulated over 50 years of natural history film-making coupled with a considered, poignant and practical analysis of where we were/are and want to be offers stark warnings, certainly, but also scope for hope and optimism too if only we can get a grip. His manner is affable and authoritative, he is the teacher every one of would…