espite his pioneering endeavours to place a spotlight firmly on the issue, climate change remains the biggest threat to the planet, according to Sir David Attenborough.

The naturalist and broadcaster, who recently celebrated 60 years documenting the wild kingdom, has delivered his stance on the topic with groundbreaking programmes Life in the Freezer and Frozen Planet. He has showcased numerous accounts of the polar ice caps melting, as well as offering theories over subsequent long-term effects on land levels, crop production and wildlife welfare.

Yet Attenborough feels another deadly, silent threat poses a far greater risk to the survival of the Earth – the growth in the world's population. 'It is – we are – the biggest menace the planet has ever faced,' he begins, speaking exclusively to FPJ. 'When I started in my career in 1952, there were 2.5 billion people on the planet. Now there are seven billion, and in 2050, we're looking at 15 billion. I ask you, where are we all going to go, where are we going to live? We all want to feed ourselves, have homes, have cars and ultimately watch our own families have their own families. The planet cannot sustain such gargantuan growth and this is, by far, our biggest concern.'

The godfather of the natural world, busier than ever with new series Natural Curiosities, Africa and Galapagos, believes the concern we should be registering over the boom in human numbers is being muted by the ongoing fears relating to the global economic slowdown. 'Unfortunately, it's been swept under the rug for another day because the recovery of the economy is of paramount interest.

'I find it odd that climate change is frequently addressed as a global threat, but where are the mentions of population increase and its detrimental consequences?

'We are steaming towards disaster, at a faster rate than was ever anticipated. I hope some sort of paralleling solution can be found before long.'

While the potential for environmental damage is colossal, Attenborough is of the opinion that the depletion of the world's crops will be the most immediate problem. 'Most think climate change is the biggest issue when it comes to the future of our crops, but overreliance from the increasing population will have a cataclysmic effect.

'Crops can't handle such pressure; it's simply a waiting game now. And it's great we're looking at organic produce, but that simply makes the challenge even greater, because in production terms ethical produce is inefficient compared to genetically modified strands.

'We know that climate is already having an effect on crops, but this will be far greater. The ripples will extend far and wide. It's a system we simply won't be able to sustain and widespread famine will become the norm, spreading from the Third World. It's an issue that must be addressed. Whether it's even acknowledged in my lifetime, who knows?'

Celebrating his 87th birthday this year, Attenborough is showing no signs of slowing his pace; quite the opposite in fact given that after a hectic 2012, he has just returned from China where his task has been to examine newly discovered fossils for the Discovery Channel. And his next stop is the Amazon, where he'll research the mechanisations of the spider's web.

And arguably the world's leading authority on the natural world is still looking to innovate in the way he presents material, with new series Natural Curiosities examining the extraordinary evolution of fascinating animals such as the giraffe, the platypus and the chameleon – for the first time ever away from their natural surroundings. Airing on Eden at the end of the month, it is an unusual departure for the jet-hopping boffin, given that it was filmed entirely on UK soil.

'It was certainly a new experience to remain on British soil. I think the furthest we strayed was up to Scotland so this series is pioneering for that sense.

'But, in addition, it looks at animals in a way that no other programme does – outside their habitat, with full focus on them. We wanted to eliminate the surrounding aspects, which can sometimes prove distracting, while focusing on the evolutionary genius of these creatures.'

The attention surrounding his advancing age is something Attenborough is understandably ill at ease discussing. 'I'm certainly aware of it – it's rather difficult to ignore it,' he laughs. 'I can't climb trees any more because of my leg and I guess I can't really move as fast either. But why slow down altogether? I have a passion for what I do and passions are what keep all of us alive.

'I just wish I didn't have to temper that passion with frustration over where the natural world is going. But I guess humans have always had to be concerned over what is around them. Nothing is sustainable forever – not even our own sustainability.

'I think what does serve us well these days is the technical age. It is an incredible blessing. Look at fresh produce, for instance – at the top level we have the sort of awareness and understanding of food production that could not have even been dreamt of two decades ago. People know where their food comes from, how it is made, and are invited to take responsibility over what they consume – for the first time ever.

'And on a really local level, the internet has done marvellous things for promoting fantastic sources of fruit, vegetables, dairy products and more – from local farmers' markets to home-delivery services. True, all of those messages are battling hard against those from the corporate giants, but people are still more aware than ever before.'

Throughout his remarkable career, Attenborough, a household favourite thanks to those dulcet, unmistakeable tones, has lain with the mountain gorillas of west Africa, swam with the Arctic narwhal, even had several species named after him including one of the world's largest carnivorous plants, Nepenthes attenboroughii, and a breed of long-beaked echidna (a sort of mini-anteater), the Zaglossus attenboroughi.

What does he perceive as his greatest achievement – the pinnacle in an existence few will ever emulate? 'I always get asked these questions and they are difficult to answer,' he says. 'How do you pick your favourite spot on the planet? And for what multitude of reasons? The world is a marvellous place and everything everywhere has its own beauty and wonder. If I have to choose, one of the big revelations for me in my career was discovering the Great Barrier Reef for the first time. It was completely mind-blowing, and every time I've gone back, it has never ceased to amaze.

'The sheer variety, the sheer beauty and abundance was a massive personal revelation. It's a wonder that simply cannot be missed. Of course, I hope my greatest achievement is still to come, just as I hope human nature's is still to come as well.'—