A new study revealed that that the increasing biofuel use in the US has led to the net increase in carbon dioxide emissions, despite previous studies suggesting that biofuel is carbon neutral.
The study, published in the journal Climatic Change, debunked all previous carbon footprint models based on lifecycle analysis that were used to develop the US Renewable Fuel Standard (RFS) and California’s Low-Carbon Fuel Standard (LCFS), which resulted to the expansion of biofuel use over the past decade.
These carbon footprint models showed that crop-based biofuels offer at least modest net greenhouse gas reductions relative to petroleum fuels.
The belief that biofuel is carbon neutral was made because plants absorb carbon dioxide as they grow. Due to this, the carbon dioxide produced when burning fuels from crops should be balanced by their carbon dioxide uptake when they grow, Natural World News reported.
However, using crop-production data from the US Department of Agriculture and the Annual Basis Carbon (ABC) accounting method, the researchers discovered that the carbon dioxide uptake of crops used for biofuels can only upset 37 percent of carbon dioxide emissions from biofuel combustion from 2005 to 2013.
“When it comes to the emissions that cause global warming, it turns out that biofuels are worse than gasoline,” said John DeCicco, a research professor at University of Michigan’s Energy Institute, in a statement.
So the underpinnings of policies used to promote biofuels for reasons of climate have now been proven to be scientifically incorrect.
Unlike lifecycle analysis, the ABC method reflects the stock-and-flow nature of the carbon cycle, recognizing that changes in the atmospheric stock depend on both inflows and outflows.
For their study, DeCicco and his team analyzed real-world data on crop production, biofuel production, fossil fuel production and vehicle emissions. Furthermore, they did not used carbon footprints models based on lifecycle analysis, nor treated biofuel as carbon neutral.
Their findings suggest that the recent expansion of biofuel industry has resulted to net increase of carbon dioxide emissions, as opposed to the result of the lifecycle analysis. Due to this, the researchers are recommending government officials and policymakers to reconsider their support for the biofuel industry.
