Having long ago thrown in with a wussy posse of environmentalists, Leonardo DiCaprio has now produced something from that commitment -- a 90 minute polemic called The 11th Hour that seeks to summarize and draw awareness to the poor health of planet Earth in general. There's hardly any new information on offer in the film, even for those with only a loose understanding of the major talking points of the environmental movement, but as a classroom teaching tool, it could serve a useful purpose. It breezes from topic to topic with great alacrity, and the bases covered include global warming, overpopulation, soil erosion and forest depletion, the political landscape vis a vie environmentalism, and the emergence and practicability of green technology. There's an abundance of talking heads in the film, and they're an eclectic bunch, ranging from the authors of scary-sounding books like The Collapse of Complex Societies, to professional climatologists and environmental consultants, to he-of-the-authoritative-sounding-voicebox Stephen Hawking, to a Native American gentlemen who represents something called the Turtle Clan, to Leo himself.

One of the most interesting points argued throughout the film is that we live during a fundamentally unnatural juncture in Earth's history, with humans living very successfully off of the "ancient sunlight" stored in non-regenerative fossil fuels, instead of basing our life cycles on the natural dawn-to-dusk cycle of daily sunlight. Having found a way to live and produce food on our own schedules instead of nature's, we've exploded our numbers beyond what the Earth can bear. There are now twice as many people as there were when Kennedy was president, and if it were not for the technological advancements of the Industrial Revolution, the planet could not sustain more than one billion. The cumulative effect of all that human activity is a terribly negative one for Earth's health, the film argues, and the planet will eventually try to reject us, like a virus. A grim showdown between us and mother nature is postulated, and the film even notes that climatologists and economists have already begun crunching numbers to see what it will cost to "replace nature."