Biofuels produced from biomass feedstocks are, by definition, carbon neutral. Yet, in a newly published article in Science, frequent biofuel critics argue that this widely held scientific convention is erroneous. They argue that biofuels and other bio-based energies should be accountable for the biogenic tailpipe and smokestack CO2 emissions that are absorbed by growing feedstocks and carbon emissions that could result from land clearing. They say existing and proposed regulations create an accounting loophole that will lead to increased deforestation.
But, according to the Renewable Fuels Association, the release of CO2 from recently living organisms has no overall effect on atmospheric CO2 levels and is therefore carbon neutral. In effect, biofuels recycle organic carbon. Conversely, accepted carbon accounting for fossil fuels such as petroleum does include tailpipe emissions from combustion. This is because the carbon in fossil fuels has been sequestered underground for millions of years rather than recently sequestered by growing organisms and cannot be naturally offset by feedstock uptake.
The Renewable Fuels Association says that based on a fair apples-to-apples comparison with petroleum, biofuels clearly offer society a lower-carbon path forward. And when it comes to the real issue – it's not accounting tactics, but whether biofuels reduce greenhouse gas emissions compared to continued petroleum use. There is clear and substantial evidence that they do. As for land conversion, the RFA says those who directly convert land for biofuel crop production or any other purpose should be severely penalized and every effort should be taken locally to prevent this type of direct action.