The producers will swap diesel generators at the studio for electric power and buy the electricity from renewable sources, and put the crew in hybrid vehicles or convert the giant production trucks to biodiesel.

And global warming will be incorporated into the plot, too, once again putting Hollywood in the forefront of bringing the issue to public attention in America. A Fox spokesman insisted the carbon reductions were real, not a publicity stunt to promote the show's upcoming storylines.

By cutting its carbon footprint by a planned one-twentyfourth, the show is expected to heavily publicise a "carbon-neutral" season finale when it is aired next summer. Filming is to start in the next few weeks.

"Global warming is a crime for which we are all guilty, from our cars, our homes and our workplaces," said Kiefer Sutherland, who plays Jack Bauer. "All of us at 24 understand the urgency of this problem and, over the next year, we will be implementing creative new ways to produce our show and significantly reduce our carbon footprint."

Sutherland will also present a series of public education videos designed to highlight simple measures that people can take to reduce their own contributions to global warming.