I think it is timely to highlight the fact that HRH Duke of Edinburgh appears to have had a pretty good understanding of environmental issues and the role of human population numbers in environmental degradation. His reputation for having a curmudgeonly persona went before him, and possibly gave him licence to blurt out his thoughts, uncensored by notions of political correctness. His gratuitous remarks to more or less strangers, regarding their appearances, or rude questions, characterised his multitudinous "gaffes". He was refreshingly "un careful" and honest in interviews, so he spoke of what many refer to as "the elephant in the room" - human population numbers - as though this reality was indeed not only visible but very obvious. He remarked in one interview that where humans are, there is nothing else (!) He was unmeasured in his comments, so his message was clear. He also remarked, in one interview, that no-one wants to talk about it [population]. I have not, so far, found an interview where any interviewer delves deeply into this with him.
Conservation of Wildlife and Natural Habitats