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Taken from the SeattlePI, the full article can be found here
From the chart it becomes very apparent that not all biofuels are created equal, and that ethanol produced from corn doesn't seem to make much sense. True, it does give farmers in the Midwest another use of their industrial grade corn, but there is very little truth behind the idea ethanol from corn will break the American dependence of foreign oil anytime soon.
What appeals to me most about the table is the consideration of carbon dioxide emissions produced per megajoule of energy created. It allows for an objective look about the various biofuel strategies and their role as carbon sequestering techniques. Even after growing, harvesting, refining, and burning, biodiesel based on algae results in a net negative carbon dioxide balance. Furthermore, algae does not have to be grown on land that could be used for food production. Now if we could combine the algae blooms produced from nitrogen enriched agriculture runoff with algae based biodiesel production, we'd really be getting somewhere ...