Because scientists just can't get enough of "the sky is falling," we have a new report from Wired referencing an article in Science, that

The problem is leaking hydrogen. Based on a 'hydrogen economy' and the estimate that 10-20% of hydrogen in systems will leak out and ascend into the atmosphere, possibly as high as the stratosphere, the scientists at CalTech think it might result in larger holes in the ozone layer (as we saw with CFCs before they were banned).