Sir David Attenborough has said it is not "sensible politics" for climate change and environmental protests to break the law.
In an interview with The Sun, the veteran broadcaster discussed environmental protests, which have soared in number and scope over the last two years, and praised the younger generation for their "passion".
But Sir David said he supported peaceful protest as the only way for young people to have their voices heard.
He added: "I don't think it is sensible politics to break the law.
"If you are any good at all, some of your demands will be met and then you will be demanding people abide by those new laws. You can't have it both ways."
Many protests have been organised by the action group Extinction Rebellion (XR), including last year's 10-day "Autumn Uprising" which saw major disruption and more than 1,700 arrests.
The group has gained international attention and support from many figures, including author Margaret Atwood.
We are thrilled to announce the global premiere of DAVID ATTENBOROUGH: A LIFE ON OUR PLANET on September 28th, followed by an exclusive conversation between Sir Michael Palin and Sir David Attenborough. Find your local cinema at https://t.co/qKqKRL23wV 🌍 #AttenboroughFilmpic.twitter.com/2rR6x3GwXE
— David Attenborough: A Life On Our Planet (@DavidALifeFilm) July 30, 2020
On Friday night, members of Extinction Rebellion targeted two News Corporation printing presses and delayed the delivery of newspapers, including The Sun.
Other demonstrations have taken place in central London in the past week.
Naturalist Sir David also said humanity as at a "crossroads" in terms of climate change, adding it is still possible to avoid the potentially "apocalyptic" consequences.
Sir David said everyday actions can be taken to help save the natural world, including being conscious of the resources we use.
He told The Sun: "Being wasteful, that is the real sin. We are astonishingly wasteful."
The broadcaster said this did not mean giving up necessities, adding: "If you behave sensibly, you shouldn't feel guilty that it has cost you some ergs (units of energy) to get from A to B.
"You can't justify everything by the cost to the environment."
Sir David gave the interview ahead of the release of documentary film A Life On Our Planet.
The film, which serves as Sir David's witness statement for the natural world, will premiere in cinemas on September 28 before launching on Netflix in the autumn.
A second documentary from Sir David, examining nature's fragile state, will air on BBC One on September 13.
Extinction: The Facts will examine what is happening to the natural world, how human activity drives extinction and why action has not been taken sooner to stem the losses, according to the BBC.