I would add a couple of ‘honourable mentions’ however…

Jacques Yves Cousteau: the visionary and inventor best known for inventing ‘SCUBA’ did more than explore the seas. He was instrumental in using the media to educate, but in a way that provided more wonder than schooling. His films were real rather than contrived. What was so significant was the way that Cousteau so subtly worked in his observations pertaining to the impact of humans on the environment. He delivered some very deep messages without being preachy. He gave hope while issuing warnings.

David Attenborough: Truly one of the pioneers of ‘real nature cinematographyn (along with the BBC of course). His ‘Zoo Quest Expeditions’ opened up the unbridled wonders of nature to the world. Being a green thinker doesn’t always have to do with conservation, sustainability, environmentalism, etc. Sometimes it’s about celebrating the non-human part of our world for being just what it is. To demonstrate the intricacies of Nature with such a mix of passion and intellect, is to both broaden the horizons of our experience and give credence to the message of others. He gave (and still gives) us the proof that there is more to the planet than just us and there are some very real reasons to measure our actions carefully.