Modern concepts considering biofuels as a green alternative to oil is less harmful to the environment. However, according to two scientists, as expressed by them in the pages of Bioenergy (GCB Bioenergy), benefits of biofuels are overpriced.
According to researchers, the calculations of greenhouse gas emissions in the production and use of biofuels do not include sensitive information, leading to distortion.
The criticism directed at scientists model the life-cycle (Life Cycle Analysis, LCA) of biofuel production. Life cycle analysis is used to collect, synthesize and study of all factors related to the production, use and disposal of fuel or product. The authors concluded that the accepted LCA model overestimates the positive aspects of biofuels compared to fossil fuels. The current estimate ignores CO2 emissions by vehicles powered by biofuels.
Supporters of biofuels believe that this carbon is not worth considering, because he collected plants grown for processing into fuel, and only returned to the wild. Critics argue that in this case, biofuels will not reduce the level of carbon in the atmosphere. Biofuels can reduce carbon emissions only if it stimulates further growth of plants or uses for the production of biomass waste, which can be expanded with the release of carbon in any way.
Revaluation of bioenergy is further strengthened when one considers that there is still little attention is paid to emissions of nitrogen fertilizer required to grow plant material. According to lead author Dr. Keith Smith (Keith Smith) University of Edinburgh: "N2O emissions from the soil makes a huge contribution to global warming, which is associated with the culture of production. Every kilogram of N2O has on the environment is about the same effect as 300 kilograms of CO2 ».
Dr. Smith says that the current method of life cycle analysis underestimate the percentage of nitrogen in fertilizers, which actually released into the atmosphere as a greenhouse gas. The authors believe that the observed increase in atmospheric N2O shows that the percentage is actually almost twice that used in the life cycle assessment of biofuels, which significantly change the result.
Since the results of a life cycle assessment is widely used, researchers Keith Smith and Timothy Sichinger (Timothy Searchinger) from Princeton University, concluded that the overall development of alternative fuels is moving in the wrong direction.
"The best opportunity to make useful biofuel, is the processing of the waste or the focus on the relatively moist, but very poor land," — said Dr. Smith. "If bioenergy crops are grown on degraded lands will be allocated fewer greenhouse gases and more contact. Additional benefits of this approach — biofuels will not compete with food production, textiles and other goods. "