(CNN) As you may have heard, celebrities have been using their clout to get out the message on climate change -- inviting the question, frequently, as to whether they're a hindrance or a help to that cause.

If there's any area where star power seems to be put to the most effective use, it's the documentary, where attaching names like Leonardo DiCaprio and Arnold Schwarzenegger helps projects that might evaporate into the ether get on the media's radar.

'Ice on Fire'

DiCaprio weighs in this week with "Ice on Fire," a better-than-most film on the topic that gets beyond the dire warnings to contemplating what can actually be done to help turn, or at least significantly curb, the tide.

For his part, Schwarzenegger plays the same role on "Wonders of the Sea," a project exploring the oceans made in conjunction with Jean-Michel Cousteau, the seafaring explorer and son of the legendary Jacques Cousteau.

At this point, subtlety isn't part of the strategy, and the time for parsing sentences and pulling punches appears to be over.

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