Sir David Attenborough believes it would now be “political suicide” for a UK party leader to deny climate change.

The TV naturalist said he was hopeful in the wake of the climate change agreement reached in Paris last month that humanity is beginning to recognise that it has to tackle global warming.

“When I look back to some of the programmes I’ve made,” he said, “I ended up saying, ‘Look, we’re wrecking the world.’ Now people believe it and understand it. The Americans have come round and this country has come round, and it didn’t start this way.”

Sir David, who turns 90 in May, declared he believed in the threat of climate change in 2004 and attended the Paris summit to promote the Global Apollo Programme which wants to make renewable energy cheaper than fossil fuels.

In an interview he also argued that overpopulation was one of the key problems facing the planet in the years ahead and that giving more personal power to women was a possible answer. “It seems to me every one of the ills of the past 200 years – hunger, famine, loss, of identity, forests disappearing, loss of dignity, overcrowding, loss of countryside – it’s all to do with increased population,” he said.

“The only way you can deal with this situation – well, I can’t see myself getting up on a soapbox and saying, ‘Stop having children’ – is when people are better off without so many children. Anywhere that women have control of their bodies and education and are literate and politically independent, the birth rate falls. Kerala in India is an example of that.”

Sir David, whose latest programme, Attenborough and the Giant Dinosaur, airs on BBC1 next Sunday, added that when people ask him how he has retained his passion for the natural world he always replies: “How did you ever lose yours.”