STEVE INSKEEP, Host:
NPR's Richard Harris has the story.
RICHARD HARRIS: If you burn ethanol from corn in your car, the government doesn't count the carbon dioxide that comes out the tailpipe as an actual carbon emission. That's because they figure the corn plant originally took that carbon dioxide out of the air, so you're just putting it back. But 13 prominent scientists point out in Science magazine that's bad logic when it comes to many types of biofuels. Author Tim Searchinger is from Princeton University, and he offers an extreme example to make the point.
INSKEEP: Even if you were to cut down the world's forests and turn them into a parking lot and take the wood and put it in a boiler, which obviously releases enormous amounts of carbon in the trees, that is treated as a pure way of reducing greenhouse gas emissions, and that's obviously an error.
HARRIS: And that error isn't trivial. It's now enshrined in European law as well as the Kyoto climate treaty.
INSKEEP: The problem is that when the world agreed to a treaty that limited the amount of carbon that goes up the smokestack, they didn't agree to limit the amount of carbon released by cutting down trees.
HARRIS: As a result of this accounting error, countries trying to reduce their carbon emissions actually have an incentive to cut down forests and burn them up, or replant the area with biofuels crops. In fact, Searchinger says power plants in northern Europe are starting to chip up wood and burn it for energy in the name of reducing emissions.
INSKEEP: The fundamental effect of this flaw is to make forests worth more dead than alive.
HARRIS: This spring, another report in Science magazine pondered what would happen in the coming decades if biofuels carbon was never counted as an emission. Jae Edmonds, at the Pacific Northwest National Lab, says they calculated that almost all the world's forests would be chopped down by the middle of this century.
M: You can't actually imagine this thing going on like this with no one noticing and no one stepping in to intervene, but the numerical experiment is instructive in that it takes the phenomena into sharp relief.
INSKEEP: The good news is, it's very easily fixable.
HARRIS: Again, Tim Searchinger. He says nations simply need to count all carbon dioxide coming out of tailpipes and smokestacks regardless of the source. Then if the source of the biofuel was a destructive one, like deforestation, there would be no carbon emissions credit. But if it was from a good source like plants grown on previously barren land, that would earn a carbon credit.
INSKEEP: So there are substantial amounts of bio-energy we can make that do give us greenhouse gas benefits. What we don't want to do is create a false and perverse incentive simply to go clear the world's forests.
HARRIS: Whether this new accounting scheme would affect the domestic biofuels industry is debatable. Bob Dinneen, president of the Renewable Fuels Association, says it shouldn't matter.
M: Some of the points that have been made in the paper today, we agree with. You should never, under any circumstance, tear down a forest for the growing of a biofuel.
HARRIS: But some scientists argue that the domestic biofuels industry does indirectly lead to deforestation in the tropics by raising the global price of corn, and encouraging farmers in South America to clear land to plant grain. Jae Edmonds, from the Pacific Northwest National Labs, says if we could place a cash value on preserving forests, that ends up being good for the atmosphere.
M: You end up not producing quite as much biofuel, but then you don't need as much because you don't have to make up for the deforestation.
(SOUNDBITE OF LAUGHTER)
HARRIS: Richard Harris, NPR News.
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