I will not analyze the movie's science here -- RealClimate does an excellent job -- other than to say it's very largely correct but ebola and avian flu have nothing to do with global warming. What really got my attention was Gore's juxtaposition of local and global imagery, particularly how they complement each other.
The film starts at a river near the Gore family farm. A minute later, we see the most famous photographs of Earth from space -- Earthrise and the full-frame Apollo 17 shot known only as 22727.
The images continue. Before even really getting into global warming, Gore shows a film of Earth's rotation taken by the Galileo spacecraft and a composite cloudless photograph of Earth (somewhat similar to the one I blogged about here). While the composite is used many times later in the film, the animation and other photos seem to be shown mostly for their emotional effect.
And they certainly do have an effect. Even for somebody who has spent a lot of time examining these images and studying their cultural meanings, it is hard to look closely at Earthrise or 22727 without being moved. The emotion is a complex mix of esthetic appreciation, awe and humility at our place in the Cosmos. If this feeling isn't spiritual, I don't know what is.
At this point, the movie gets into the nitty-gritty of global climate change. Here, the only significant global images are maps, often superimposed on the composite image mentioned above. Instead, we see a lot of clips of particular places on Earth where global warming has been studied or is having an effect. The movie shows the disappearing glaciers of Kilimanjaro, a collapsed building on melting Siberian permafrost, drowning atolls in the South Pacific and New Orleans after Hurricane Katrina. There are also a few images of pollution sources, but Gore mostly presents this information in graphs.
Here, it makes sense to detour briefly into the relationship between the local and the global. The two perspectives are often presented as opposites, but this is a false dichotomy. "For this local scene to exist," writes geographer Denis Wood in Five Billion Years of Global Change, " the whole world had to be just so." Each place is an intersection of a myriad of global processes, from plate tectonics to the movements of plants and animals to cultural diffusion. Simultaneously, plate tectonics, biological range shifts and cultural diffusion result from local conditions in places all over the world. Everything happens somewhere, but global systems link localities. The local and the global co-create each other.
At the end of the film, Gore comes to another photograph of Earth, this one taken from beyond the orbit of the outermost planet. Usually referred to as the Pale Blue Dot image, this photograph shows Earth as a small dot, a mote of dust caught in a sunbeam. Carl Sagan, whose idea it was to take the picture, wrote eloquently about it in a book titled Pale Blue Dot. Unfortunately, Gore didn't quote him, so I will end by doing so.
That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.
The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves.
It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.