Monday, February 11, 2008

Yes, biofuels emit carbon dioxide too!

An article in The New York Times by Elisabeth Rosenthal entitled "Biofuels Deemed a Greenhouse Threat" reminds us that even over-hyped biofuels are not a magic solution to Global Warming and Climate Change. As The Times tells us:

Almost all biofuels used today cause more greenhouse gas emissions than conventional fuels if the full emissions costs of producing these "green" fuels are taken into account, two studies being published Thursday have concluded.

The benefits of biofuels have come under increasing attack in recent months, as scientists took a closer look at the global environmental cost of their production. These latest studies, published in the prestigious journal Science, are likely to add to the controversy.

These studies for the first time take a detailed, comprehensive look at the emissions effects of the huge amount of natural land that is being converted to cropland globally to support biofuels development.

The destruction of natural ecosystems -- whether rain forest in the tropics or grasslands in South America -- not only releases greenhouse gases into the atmosphere when they are burned and plowed, but also deprives the planet of natural sponges to absorb carbon emissions. Cropland also absorbs far less carbon than the rain forests or even scrubland that it replaces.

Together the two studies offer sweeping conclusions: It does not matter if it is rain forest or scrubland that is cleared, the greenhouse gas contribution is significant. More important, they discovered that, taken globally, the production of almost all biofuels resulted, directly or indirectly, intentionally or not, in new lands being cleared, either for food or fuel.

"When you take this into account, most of the biofuel that people are using or planning to use would probably increase greenhouse gasses substantially," said Timothy Searchinger, lead author of one of the studies and a researcher in environment and economics at Princeton University. "Previously there's been an accounting error: land use change has been left out of prior analysis."

Oops!

The simple, undeniable fact is that biofuel is still a hydrocarbon and burning of hydrocarbons releases carbon dioxide (and water vapor which is also a greenhouse gas.)

All along, we have been counting on many thousands of square miles of plants to continue absorbing carbon dioxide, but by misguidedly focusing energy on land-intensive biofuels, we are giving up one of our best sinks for excess carbon dioxide in the atmosphere. Further evidence that ill-considered, short-sighted "fixes" for environmental issues is not a very good idea.

In short, biofuels are in fact a good idea, but pursuing them as a land-intensive "crop" is not environmentally sustainable.

Algae-based biofuels are one interesting alternative.

-- Jack Krupansky

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