by Marianne Lavelle

When President Obama unveiled his long-awaited climate change strategy this week, he never mentioned biofuels. (See “Obama Unveils Climate Strategy.”) But with nearly a third of U.S. greenhouse gas emissions due to burning petroleum for transportation, a key and controversial question is what role plant-based alternatives can play in cutting the nation’s carbon emissions.

As part of National Geographic’s Great Energy Challenge initiative, we brought together two dozen experts from industry, academia, and environmental organizations to discuss whether biofuel can be a sustainable part of a cleaner energy future. (See in-depth coverage at Biofuels at a Crossroads, and vote and comment here: The Big Energy Question: Are Biofuels Worth the Investment?“) The forum Wednesday at National Geographic’s Washington, D.C. headquarters was timely, not just because the group convened the day after the President’s long-awaited climate speech.

It also came at a time that U.S. biofuels policy is under fire, as petroleum refiners are leading an effort to roll back the mandate (the Renewable Fuel Standard) that gradually increasing volumes of biofuels be blended into the U.S. transportation fuel mix.

Thanks to that policy begun in 2005, ethanol made from corn now makes up about 10 percent of U.S. gasoline consumption by volume; it’s one of the reasons that U.S. gasoline demand has fallen 6 percent from its peak in 2007. But it’s not clear that today’s biofuels can (or should) grow further.

For one thing, the vast majority of vehicles on U.S. highways today were not designed by automakers to run on a high volume of ethanol, even though the technology for flexible fuel vehicles is well-known and inexpensive. Most of the autos sold in Brazil are flex fuel, which has helped that nation do more than any other to give motorists a choice of fuel beyond gasoline. (See related, “Brazil Ethanol Looks to Sweeten More Gas Tanks.”)

But then there are the far thornier issues of food, water, and land. More than 40 percent of the U.S. corn crop is going to make ethanol and ethanol by-products (About one-third of each bushel dry-processed for ethanol is turned into livestock feed product.) Since most of the U.S. corn crop is rain-fed, drought is a risk, and the irrigation required is heavy in some areas. (See related, “Water Demand for Energy to Double by 2035,” and “Drought Withers U.S. Corn Crop, Heats Debate on Ethanol.”) Even more difficult is the indirect land impact issue: whether the increasing use of grain for fuel has prompted other nations to destroy valuable rainforest ecosystems for agriculture to make up for lost U.S. exports.

Any effort to undo the U.S. mandate on biofuels, however, would affect more than corn ethanol. It would also unravel the incentives that were meant to spur the development of more environmentally friendly alternative biofuels made from feedstocks like waste, grasses, and wood chips. (See related: “Beyond Ethanol: Drop-In Biofuels Squeeze Gasoline From Plants.”) Although cellulosic biofuel has not come on line as quickly as hoped, the first plants are opening, with thermo-chemical and biotechnology processes showing promise. Yet the industry’s future is precarious due to lack of capital and lenders willing to take a risk on the technology.

That’s why we brought together some of the leading thinkers on this complex issue for our forum, Big Energy Question: Biofuels at a Crossroads. You can read some of their comments and see photo coverage of the forum above.

What do you think about biofuels? Vote and comment here: The Big Energy Question: Are Biofuels Worth the Investment?


Read the article at National Geographic

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