The actor Leonardo DiCaprio has one in Mexico and the film director Bernardo Bertolucci has one in Scotland.

The latest “must-have” for those in the film industry is a newly planted forest. The phenomenon, known as “going carbon neutral”, is intended to reduce global warming by encouraging filmmakers to plant trees to “neutralise” the greenhouse gases created in the production of their art.

The idea, which is also growing in popularity among the general public in Britain and elsewhere, involves the calculation of how much carbon dioxide any activity produces, and then compensating for the pollution by planting trees.

Dan Morrell, the founder of Future Forests, a London company which has registered the word CarbonNeutral as a brand, said: “We all produce carbon dioxide: by driving cars, boiling the kettle and watching television. The good news is we can do something about it.”

DiCaprio, one of the most bankable stars in Hollywood after Romeo and Juliet, Titanic and Gangs of New York, claims to be a “carbon-neutral citizen”. Working with Future Forests, he has planted thousands of trees, creating The Leonardo DiCaprio Forest in Mexico, to offset the estimated 11 tons of carbon dioxide he produces each year.

Other Hollywood stars to have planted forests include Kirsten Dunst, best known for her role in Spiderman, Jake Gyllenhaal, who starred in The Good Girl, and Dominic Monaghan, one of the hobbits in The Lord of the Rings trilogy.

Bertolucci, the Oscar-winning Italian film director, who made Last Tango in Paris and The Last Emperor, has gone one step further and created the first “totally carbon-neutral” film. He has had 1,000 trees planted on his behalf to offset the estimated 790 tons of carbon dioxide produced in making his latest film, The Dreamers.

Jeremy Thomas, the film’s producer, said: “The world is getting hotter and hotter and this is our way of doing something about it. It only costs a couple of thousand pounds to counterbalance the environmental damage of a film. That’s nothing compared to the millions it takes to make a film.

“Eventually there will be forests across the world that have been created by those in the film industry.”

For ordinary citizens seeking to follow the CarbonNeutral regime, planting one tree will offset the carbon dioxide produced by boiling a kettle 28,000 times, or leaving a television set switched on for two years, or flying 2,500 miles — equivalent to a return flight to Portugal.

Larry Lohmann, former editor of The Ecologist and a campaigner for environmental issues, said, despite the film industry’s enthusiasm, he was very suspicious of “the latest green fad”.

He said: “It’s a booming business and these film stars find the concept very attractive. It allows them to carry on burning fossil fuels, to continue creating carbon dioxide, and for the price of a few pounds they can walk around feeling righteous about their part in saving the environment.

“The truth is that there is no reliable scientific method of measuring reabsorption. Anyone claiming that they can neutralise emissions by planting a certain number of trees is completely irresponsible and anyone who believes them is foolish.”

The film world is, however, far from the only industry to adopt the carbon-neutral concept.

The Rolling Stones paid for a forest on the Isle of Skye to offset the carbon dioxide emitted during their nine-day British tour. It was estimated that to balance the environmental effect of the tour, the rock band had to plant 2,800 trees.