Scientists Warn of Climate Accounting Glitch

An accounting glitch in the way some greenhouse gas emissions are calculated could critically hobble efforts to reduce them in coming years as nations move to combat global warming, scientists warn in a new report.

The accounting error even gives the impression that clearing the world’s forests, which absorb and thereby diminish heat-trapping carbon dioxide, is good for the climate, the scientists write in an article published Friday in the journal Science.

The glitch boils down to this: in emission calculations, all fuel derived from plants and other organic sources — including ethanol — is generally treated as if it had no effect on carbon dioxide in the atmosphere, even though though biofuels do emit carbon dioxide when burned.

This might make sense if the source of the fuel were, say, a crop of corn grown specifically for use as fuel, because the crop would have absorbed carbon dioxide as it grew, offsetting what it emits when ultimately burned.

But if an existing stand of forest land is cleared for fuel, its ability to absorb carbon dioxide is lost, and the net balance of the gas in the atmosphere goes up.


The New York Times