Humans are a "plague on the Earth", according to naturalist and documentary-maker David Attenborough.
Attenborough told Britain's Radio Times that humanity must limit population growth or "the natural world will do it for us".
"We are a plague on the Earth. It's coming home to roost over the next 50 years or so," the renowned conservationist warned.
"It's not just climate change; it's sheer space, places to grow food for this enormous horde."
The 86-year-old said human population growth needed to be curbed.
"We keep putting on programmes about famine in Ethiopia; that's what's happening. Too many people there. They can't support themselves - and it's not an inhuman thing to say. It's the case.
"Until humanity manages to sort itself out and get a co-ordinated view about the planet it's going to get worse and worse," he told Radio Times.
Attenborough's latest series Natural Curiosities is set to hit screens in the UK this week, while Africa, which he hosts, is currently screening in New Zealand.