Captain Planet and the Planeteers was for a short moment in time, one of the most popular cartoons of the '90s. The environmentally-conscious series aired on Ted Turner's TBS and followed a group of do-gooding youngsters, each with an elemental ring (all except for the weird kid with a "Heart" ring) that helped them fight those who would harm the Earth. When the powers of the ring were combined they summoned the mighty Captain Planet, who really hates it when you don't recycle.
A live-action film was reportedly in the works a few years ago, but the deal between producers Don Murphy, Susan Montford, and Cartoon Network fell through. Now THR reports that Sony is in final negotiations to pick up the project, with Mark Gordon joining Murphy and Montford in producing. There are no other details at this stage as writers and directors still need to be hired, but one can assume the basic premise will remain intact.
Considering all of the attention of late on environmental disasters, the danger of the Keystone Pipeline, and energy independence, this is probably the best time to try and launch a Captain Planet franchise. If Sony is smart, they'll know the only guy to play Captain Planet is Don Cheadle.