In my personal belief, the big problem with climate change is getting people to understand the magnitude and scale that we're dealing with. If you buy a vehicle that gets 35 miles to the gallon, that means nothing; it's not enough. We need to make changes across society and in every piece of the energy pie.
In comics the reader is in complete control of the experience. They can read it at their own pace, and if there's a piece of dialogue that seems to echo something a few pages back, they can flip back and check it out, whereas the audience for a film is being dragged through the experience at the speed of 24 frames per second.