© ReutersThe Prince said if the world carries on 'business as usual' then the human race itself could be wiped out
Referring to himself as "an endangered species", he warned that the world is already in the "sixth extinction event", with species dying out at a much faster rate than at any time since the death of most of the dinosaurs 65 million years ago.
Despite campaigning for years on global warming, he said climate change was not the only problem but merely speeding up the "rapacious" destruction of natural resources like water, land and food that humans need to survive.
The Prince said if the world carries on "business as usual" then the human race itself could be in danger.
"We are, of course, witnessing what some people call the sixth great extinction event - the continued erosion of much of the Earth's vital biodiversity caused by a whole host of pressures, from the rising demand for land to the corrosive effects of all kinds of pollution," he said.
"This is an important point that needs to be stressed more than it is, because its ultimate impact is plainly not at all clear to most people - without the biodiversity that is so threatened, we won't be able to survive ourselves."
Alluding to his "spiritual connection to nature", the Prince said mankind must also protect other species from extinction.
"It may not seem to make much difference economically if the swallows, swifts and house martins no longer turn up each spring, but what would life be like if we just accepted their extinction because their habitats have been destroyed?"
The Prince follows in the footsteps of his father the Duke of Edinburgh who was President of the UK arm of WWF UK before taking on the top role of the international organisation.
The Royal joked that as a "rare species" himself, he has always felt a close connection to the work of WWF.
"Perhaps I warmed to your work from such an early age because, from the outset, you stood up for endangered species!"
The WWF was set up 50 years ago to protect endangered species like the panda but Prince Charles said that the challenge today is far greater.
He said the only way to protect wildlife and ultimately the humans who rely on these 'ecosystem services' is to transform the world economy so that growth is not at the expense of nature.
He referred to a "sustainability revolution" that would force people to change their lifestyles so they consume less petrol, food and other resources.
"History will not judge us by how much economic growth we achieve in the immediate years ahead, nor by how much we expand material consumption, but by the legacy for our grandchildren and their grandchildren," he said. "We are consuming what is rightfully theirs by sacrificing long-term progress on the altar of immediate satisfaction. That is hardly responsible behaviour. There is an urgent need for all of us to concentrate our efforts on sustaining, nurturing and protecting the Earth's natural capital and, moreover, reshaping our economic system so that Nature sits at the very heart of our thinking."
In a speech at St James's Palace to environmentalists, staff the Prince warned that the WWF "may regret" taking him on.
He has faced criticism for his views on the environment and voiced frustration at the failure of governments to address the issue, but he insisted that by working together humanity will "perform remarkable feats of innovation to secure a stable environment".
"As many of you will know, I have been harping on about these challenges for many years and although this leads to inevitable criticism from some quarters, I must tell you that I put up with it because the issues we face are so important. None of us must be afraid to be stand up and be counted."
As a card-carrying depopulist, I'm wondering what Prince Charles wants us to stand up to be counted FOR...removal?